Class IOUtils
This class provides static utility methods for input/output operations.
- closeQuietly - these methods close a stream ignoring nulls and exceptions
- toXxx/read - these methods read data from a stream
- write - these methods write data to a stream
- copy - these methods copy all the data from one stream to another
- contentEquals - these methods compare the content of two streams
The byte-to-char methods and char-to-byte methods involve a conversion step. Two methods are provided in each case, one that uses the platform default encoding and the other which allows you to specify an encoding. You are encouraged to always specify an encoding because relying on the platform default can lead to unexpected results, for example when moving from development to production.
 All the methods in this class that read a stream are buffered internally.
 This means that there is no cause to use a BufferedInputStream
 or BufferedReader. The default buffer size of 4K has been shown
 to be efficient in tests.
 
The various copy methods all delegate the actual copying to one of the following methods:
- copyLarge(InputStream, OutputStream, byte[])
- copyLarge(InputStream, OutputStream, long, long, byte[])
- copyLarge(Reader, Writer, char[])
- copyLarge(Reader, Writer, long, long, char[])
copy(InputStream, OutputStream) calls copyLarge(InputStream, OutputStream)
 which calls copy(InputStream, OutputStream, int) which creates the buffer and calls
 copyLarge(InputStream, OutputStream, byte[]).
 Applications can re-use buffers by using the underlying methods directly. This may improve performance for applications that need to do a lot of copying.
Wherever possible, the methods in this class do not flush or close the stream. This is to avoid making non-portable assumptions about the streams' origin and further use. Thus the caller is still responsible for closing streams after use.
Provenance: Excalibur.
- 
Field SummaryFieldsModifier and TypeFieldDescriptionstatic final intCR char '13'.static final intThe default buffer size (8192) to use in copy methods.static final charThe system directory separator character.static final charThe Unix directory separator character ''/''.static final charThe Windows directory separator character ''\\''.static final byte[]A singleton empty byte array.static final intRepresents the end-of-file (or stream) value -1.static final intLF char '10'.static final StringDeprecated.static final StringThe Unix line separator string.static final StringThe Windows line separator string.
- 
Constructor SummaryConstructors
- 
Method SummaryModifier and TypeMethodDescriptionstatic BufferedInputStreambuffer(InputStream inputStream) Returns the given InputStream if it is already aBufferedInputStream, otherwise creates a BufferedInputStream from the given InputStream.static BufferedInputStreambuffer(InputStream inputStream, int size) Returns the given InputStream if it is already aBufferedInputStream, otherwise creates a BufferedInputStream from the given InputStream.static BufferedOutputStreambuffer(OutputStream outputStream) Returns the given OutputStream if it is already aBufferedOutputStream, otherwise creates a BufferedOutputStream from the given OutputStream.static BufferedOutputStreambuffer(OutputStream outputStream, int size) Returns the given OutputStream if it is already aBufferedOutputStream, otherwise creates a BufferedOutputStream from the given OutputStream.static BufferedReaderReturns the given reader if it is already aBufferedReader, otherwise creates a BufferedReader from the given reader.static BufferedReaderReturns the given reader if it is already aBufferedReader, otherwise creates a BufferedReader from the given reader.static BufferedWriterReturns the given Writer if it is already aBufferedWriter, otherwise creates a BufferedWriter from the given Writer.static BufferedWriterReturns the given Writer if it is already aBufferedWriter, otherwise creates a BufferedWriter from the given Writer.static byte[]Returns a new byte array of sizeDEFAULT_BUFFER_SIZE.static byte[]byteArray(int size) Returns a new byte array of the given size.static voidCloses the givenCloseableas a null-safe operation.static voidCloses the givenCloseables as null-safe operations.static voidclose(Closeable closeable, IOConsumer<IOException> consumer) Closes the givenCloseableas a null-safe operation.static voidclose(URLConnection conn) Closes a URLConnection.static voidcloseQuietly(Closeable closeable) Closes aCloseableunconditionally.static voidcloseQuietly(Closeable... closeables) Closes aCloseableunconditionally.static voidcloseQuietly(Closeable closeable, Consumer<Exception> consumer) Closes the givenCloseableas a null-safe operation while consuming IOException by the givenconsumer.static voidcloseQuietly(InputStream input) Closes anInputStreamunconditionally.static voidcloseQuietly(OutputStream output) Closes anOutputStreamunconditionally.static voidcloseQuietly(Reader reader) Closes anReaderunconditionally.static voidcloseQuietly(Writer writer) Closes anWriterunconditionally.static voidcloseQuietly(Iterable<Closeable> closeables) Closes an iterable ofCloseableunconditionally.static voidcloseQuietly(ServerSocket serverSocket) Closes aServerSocketunconditionally.static voidcloseQuietly(Socket socket) Closes aSocketunconditionally.static voidcloseQuietly(Selector selector) Closes aSelectorunconditionally.static voidcloseQuietly(Stream<Closeable> closeables) Closes a stream ofCloseableunconditionally.static longconsume(InputStream input) Consumes bytes from aInputStreamand ignores them.static longConsumes characters from aReaderand ignores them.static booleancontentEquals(InputStream input1, InputStream input2) Compares the contents of two Streams to determine if they are equal or not.static booleancontentEquals(Reader input1, Reader input2) Compares the contents of two Readers to determine if they are equal or not.static booleancontentEqualsIgnoreEOL(Reader reader1, Reader reader2) Compares the contents of two Readers to determine if they are equal or not, ignoring EOL characters.static QueueInputStreamcopy(ByteArrayOutputStream outputStream) Copies bytes from aByteArrayOutputStreamto aQueueInputStream.static intcopy(InputStream inputStream, OutputStream outputStream) Copies bytes from anInputStreamto anOutputStream.static longcopy(InputStream inputStream, OutputStream outputStream, int bufferSize) Copies bytes from anInputStreamto anOutputStreamusing an internal buffer of the given size.static voidcopy(InputStream input, Writer writer) Deprecated.Usecopy(InputStream, Writer, Charset)insteadstatic voidcopy(InputStream input, Writer writer, String inputCharsetName) Copies bytes from anInputStreamto chars on aWriterusing the specified character encoding.static voidcopy(InputStream input, Writer writer, Charset inputCharset) Copies bytes from anInputStreamto chars on aWriterusing the specified character encoding.static voidcopy(Reader reader, OutputStream output) Deprecated.Usecopy(Reader, OutputStream, Charset)insteadstatic voidcopy(Reader reader, OutputStream output, String outputCharsetName) Copies chars from aReaderto bytes on anOutputStreamusing the specified character encoding, and calling flush.static voidcopy(Reader reader, OutputStream output, Charset outputCharset) Copies chars from aReaderto bytes on anOutputStreamusing the specified character encoding, and calling flush.static intstatic longcopy(Reader reader, Appendable output) Copies chars from aReaderto aAppendable.static longcopy(Reader reader, Appendable output, CharBuffer buffer) Copies chars from aReaderto anAppendable.static longCopies bytes from aURLto anOutputStream.static longcopy(URL url, OutputStream outputStream) Copies bytes from aURLto anOutputStream.static longcopyLarge(InputStream inputStream, OutputStream outputStream) Copies bytes from a large (over 2GB)InputStreamto anOutputStream.static longcopyLarge(InputStream inputStream, OutputStream outputStream, byte[] buffer) Copies bytes from a large (over 2GB)InputStreamto anOutputStream.static longcopyLarge(InputStream input, OutputStream output, long inputOffset, long length) Copies some or all bytes from a large (over 2GB)InputStreamto anOutputStream, optionally skipping input bytes.static longcopyLarge(InputStream input, OutputStream output, long inputOffset, long length, byte[] buffer) Copies some or all bytes from a large (over 2GB)InputStreamto anOutputStream, optionally skipping input bytes.static longstatic longstatic longCopies some or all chars from a large (over 2GB)InputStreamto anOutputStream, optionally skipping input chars.static longCopies some or all chars from a large (over 2GB)InputStreamto anOutputStream, optionally skipping input chars.static intlength(byte[] array) Returns the length of the given array in a null-safe manner.static intlength(char[] array) Returns the length of the given array in a null-safe manner.static intlength(CharSequence csq) Returns the length of the given CharSequence in a null-safe manner.static intReturns the length of the given array in a null-safe manner.static LineIteratorlineIterator(InputStream input, String charsetName) Returns an Iterator for the lines in anInputStream, using the character encoding specified (or default encoding if null).static LineIteratorlineIterator(InputStream input, Charset charset) Returns an Iterator for the lines in anInputStream, using the character encoding specified (or default encoding if null).static LineIteratorlineIterator(Reader reader) Returns an Iterator for the lines in aReader.static intread(InputStream input, byte[] buffer) Reads bytes from an input stream.static intread(InputStream input, byte[] buffer, int offset, int length) Reads bytes from an input stream.static intReads characters from an input character stream.static intReads characters from an input character stream.static intread(ReadableByteChannel input, ByteBuffer buffer) Reads bytes from a ReadableByteChannel.static voidreadFully(InputStream input, byte[] buffer) Reads the requested number of bytes or fail if there are not enough left.static voidreadFully(InputStream input, byte[] buffer, int offset, int length) Reads the requested number of bytes or fail if there are not enough left.static byte[]readFully(InputStream input, int length) Reads the requested number of bytes or fail if there are not enough left.static voidReads the requested number of characters or fail if there are not enough left.static voidReads the requested number of characters or fail if there are not enough left.static voidreadFully(ReadableByteChannel input, ByteBuffer buffer) Reads the requested number of bytes or fail if there are not enough left.readLines(InputStream input) Deprecated.UsereadLines(InputStream, Charset)insteadreadLines(InputStream input, String charsetName) Gets the contents of anInputStreamas a list of Strings, one entry per line, using the specified character encoding.readLines(InputStream input, Charset charset) Gets the contents of anInputStreamas a list of Strings, one entry per line, using the specified character encoding.Gets the contents of aReaderas a list of Strings, one entry per line.readLines(CharSequence csq) Gets the contents of aCharSequenceas a list of Strings, one entry per line.static byte[]resourceToByteArray(String name) Gets the contents of a resource as a byte array.static byte[]resourceToByteArray(String name, ClassLoader classLoader) Gets the contents of a resource as a byte array.static StringresourceToString(String name, Charset charset) Gets the contents of a resource as a String using the specified character encoding.static StringresourceToString(String name, Charset charset, ClassLoader classLoader) Gets the contents of a resource as a String using the specified character encoding.static URLresourceToURL(String name) Gets a URL pointing to the given resource.static URLresourceToURL(String name, ClassLoader classLoader) Gets a URL pointing to the given resource.static longskip(InputStream input, long skip) Skips bytes from an input byte stream.static longskip(InputStream input, long skip, Supplier<byte[]> skipBufferSupplier) Skips bytes from an input byte stream.static longSkips characters from an input character stream.static longskip(ReadableByteChannel input, long toSkip) Skips bytes from a ReadableByteChannel.static voidskipFully(InputStream input, long toSkip) Skips the requested number of bytes or fail if there are not enough left.static voidskipFully(InputStream input, long toSkip, Supplier<byte[]> skipBufferSupplier) Skips the requested number of bytes or fail if there are not enough left.static voidSkips the requested number of characters or fail if there are not enough left.static voidskipFully(ReadableByteChannel input, long toSkip) Skips the requested number of bytes or fail if there are not enough left.static InputStreamtoBufferedInputStream(InputStream input) Fetches entire contents of anInputStreamand represent same data as result InputStream.static InputStreamtoBufferedInputStream(InputStream input, int size) Fetches entire contents of anInputStreamand represent same data as result InputStream.static BufferedReadertoBufferedReader(Reader reader) Returns the given reader if it is aBufferedReader, otherwise creates a BufferedReader from the given reader.static BufferedReadertoBufferedReader(Reader reader, int size) Returns the given reader if it is aBufferedReader, otherwise creates a BufferedReader from the given reader.static byte[]toByteArray(InputStream inputStream) Gets the contents of anInputStreamas abyte[].static byte[]toByteArray(InputStream input, int size) Gets the contents of anInputStreamas abyte[].static byte[]toByteArray(InputStream input, long size) Gets contents of anInputStreamas abyte[].static byte[]toByteArray(Reader reader) Deprecated.UsetoByteArray(Reader, Charset)insteadstatic byte[]toByteArray(Reader reader, String charsetName) Gets the contents of aReaderas abyte[]using the specified character encoding.static byte[]toByteArray(Reader reader, Charset charset) Gets the contents of aReaderas abyte[]using the specified character encoding.static byte[]toByteArray(String input) Deprecated.UseString.getBytes()insteadstatic byte[]toByteArray(URI uri) Gets the contents of aURIas abyte[].static byte[]toByteArray(URL url) Gets the contents of aURLas abyte[].static byte[]toByteArray(URLConnection urlConnection) Gets the contents of aURLConnectionas abyte[].static char[]toCharArray(InputStream inputStream) Deprecated.UsetoCharArray(InputStream, Charset)insteadstatic char[]toCharArray(InputStream inputStream, String charsetName) Gets the contents of anInputStreamas a character array using the specified character encoding.static char[]toCharArray(InputStream inputStream, Charset charset) Gets the contents of anInputStreamas a character array using the specified character encoding.static char[]toCharArray(Reader reader) Gets the contents of aReaderas a character array.static InputStreamtoInputStream(CharSequence input) Deprecated.UsetoInputStream(CharSequence, Charset)insteadstatic InputStreamtoInputStream(CharSequence input, String charsetName) Converts the specified CharSequence to an input stream, encoded as bytes using the specified character encoding.static InputStreamtoInputStream(CharSequence input, Charset charset) Converts the specified CharSequence to an input stream, encoded as bytes using the specified character encoding.static InputStreamtoInputStream(String input) Deprecated.UsetoInputStream(String, Charset)insteadstatic InputStreamtoInputStream(String input, String charsetName) Converts the specified string to an input stream, encoded as bytes using the specified character encoding.static InputStreamtoInputStream(String input, Charset charset) Converts the specified string to an input stream, encoded as bytes using the specified character encoding.static StringtoString(byte[] input) Deprecated.UseString(byte[])insteadstatic StringGets the contents of abyte[]as a String using the specified character encoding.static StringtoString(InputStream input) Deprecated.UsetoString(InputStream, Charset)insteadstatic StringtoString(InputStream input, String charsetName) Gets the contents of anInputStreamas a String using the specified character encoding.static StringtoString(InputStream input, Charset charset) Gets the contents of anInputStreamas a String using the specified character encoding.static StringGets the contents of aReaderas a String.static StringDeprecated.UsetoString(URI, Charset)insteadstatic StringGets the contents at the given URI.static StringGets the contents at the given URI.static StringDeprecated.UsetoString(URL, Charset)insteadstatic StringGets the contents at the given URL.static StringGets the contents at the given URL.static StringtoString(IOSupplier<InputStream> input, Charset charset) Gets the contents of anInputStreamfrom a supplier as a String using the specified character encoding.static StringtoString(IOSupplier<InputStream> input, Charset charset, IOSupplier<String> defaultString) Gets the contents of anInputStreamfrom a supplier as a String using the specified character encoding.static voidwrite(byte[] data, OutputStream output) Writes bytes from abyte[]to anOutputStream.static voidDeprecated.Usewrite(byte[], Writer, Charset)insteadstatic voidWrites bytes from abyte[]to chars on aWriterusing the specified character encoding.static voidWrites bytes from abyte[]to chars on aWriterusing the specified character encoding.static voidwrite(char[] data, OutputStream output) Deprecated.Usewrite(char[], OutputStream, Charset)insteadstatic voidwrite(char[] data, OutputStream output, String charsetName) Writes chars from achar[]to bytes on anOutputStreamusing the specified character encoding.static voidwrite(char[] data, OutputStream output, Charset charset) Writes chars from achar[]to bytes on anOutputStreamusing the specified character encoding.static voidWrites chars from achar[]to aWriterstatic voidwrite(CharSequence data, OutputStream output) Deprecated.Usewrite(CharSequence, OutputStream, Charset)insteadstatic voidwrite(CharSequence data, OutputStream output, String charsetName) Writes chars from aCharSequenceto bytes on anOutputStreamusing the specified character encoding.static voidwrite(CharSequence data, OutputStream output, Charset charset) Writes chars from aCharSequenceto bytes on anOutputStreamusing the specified character encoding.static voidwrite(CharSequence data, Writer writer) Writes chars from aCharSequenceto aWriter.static voidwrite(StringBuffer data, OutputStream output) Deprecated.static voidwrite(StringBuffer data, OutputStream output, String charsetName) Deprecated.static voidwrite(StringBuffer data, Writer writer) Deprecated.static voidwrite(String data, OutputStream output) Deprecated.Usewrite(String, OutputStream, Charset)insteadstatic voidwrite(String data, OutputStream output, String charsetName) Writes chars from aStringto bytes on anOutputStreamusing the specified character encoding.static voidwrite(String data, OutputStream output, Charset charset) Writes chars from aStringto bytes on anOutputStreamusing the specified character encoding.static voidstatic voidwriteChunked(byte[] data, OutputStream output) Writes bytes from abyte[]to anOutputStreamusing chunked writes.static voidwriteChunked(char[] data, Writer writer) Writes chars from achar[]to aWriterusing chunked writes.static voidwriteLines(Collection<?> lines, String lineEnding, OutputStream output) Deprecated.static voidwriteLines(Collection<?> lines, String lineEnding, OutputStream output, String charsetName) Writes theObject.toString()value of each item in a collection to anOutputStreamline by line, using the specified character encoding and the specified line ending.static voidwriteLines(Collection<?> lines, String lineEnding, OutputStream output, Charset charset) Writes theObject.toString()value of each item in a collection to anOutputStreamline by line, using the specified character encoding and the specified line ending.static voidwriteLines(Collection<?> lines, String lineEnding, Writer writer) Writes theObject.toString()value of each item in a collection to aWriterline by line, using the specified line ending.static Writerwriter(Appendable appendable) Returns the given Appendable if it is already aWriter, otherwise creates a Writer wrapper around the given Appendable.
- 
Field Details- 
CRCR char '13'.- Since:
- 2.9.0
- See Also:
 
- 
DEFAULT_BUFFER_SIZEThe default buffer size (8192) to use in copy methods.- See Also:
 
- 
DIR_SEPARATORThe system directory separator character.
- 
DIR_SEPARATOR_UNIXThe Unix directory separator character ''/''.- See Also:
 
- 
DIR_SEPARATOR_WINDOWSThe Windows directory separator character ''\\''.- See Also:
 
- 
EMPTY_BYTE_ARRAYA singleton empty byte array.- Since:
- 2.9.0
 
- 
EOFRepresents the end-of-file (or stream) value -1.- Since:
- 2.5 (made public)
- See Also:
 
- 
LFLF char '10'.- Since:
- 2.9.0
- See Also:
 
- 
LINE_SEPARATORDeprecated.The system line separator string.
- 
LINE_SEPARATOR_UNIXThe Unix line separator string.- See Also:
 
- 
LINE_SEPARATOR_WINDOWSThe Windows line separator string.- See Also:
 
 
- 
- 
Constructor Details- 
IOUtilsDeprecated.TODO Make private in 3.0.Instances should NOT be constructed in standard programming.
 
- 
- 
Method Details- 
bufferReturns the given InputStream if it is already aBufferedInputStream, otherwise creates a BufferedInputStream from the given InputStream.- Parameters:
- inputStream- the InputStream to wrap or return (not null)
- Returns:
- the given InputStream or a new BufferedInputStreamfor the given InputStream
- Throws:
- NullPointerException- if the input parameter is null
- Since:
- 2.5
 
- 
bufferReturns the given InputStream if it is already aBufferedInputStream, otherwise creates a BufferedInputStream from the given InputStream.- Parameters:
- inputStream- the InputStream to wrap or return (not null)
- size- the buffer size, if a new BufferedInputStream is created.
- Returns:
- the given InputStream or a new BufferedInputStreamfor the given InputStream
- Throws:
- NullPointerException- if the input parameter is null
- Since:
- 2.5
 
- 
bufferReturns the given OutputStream if it is already aBufferedOutputStream, otherwise creates a BufferedOutputStream from the given OutputStream.- Parameters:
- outputStream- the OutputStream to wrap or return (not null)
- Returns:
- the given OutputStream or a new BufferedOutputStreamfor the given OutputStream
- Throws:
- NullPointerException- if the input parameter is null
- Since:
- 2.5
 
- 
bufferReturns the given OutputStream if it is already aBufferedOutputStream, otherwise creates a BufferedOutputStream from the given OutputStream.- Parameters:
- outputStream- the OutputStream to wrap or return (not null)
- size- the buffer size, if a new BufferedOutputStream is created.
- Returns:
- the given OutputStream or a new BufferedOutputStreamfor the given OutputStream
- Throws:
- NullPointerException- if the input parameter is null
- Since:
- 2.5
 
- 
bufferReturns the given reader if it is already aBufferedReader, otherwise creates a BufferedReader from the given reader.- Parameters:
- reader- the reader to wrap or return (not null)
- Returns:
- the given reader or a new BufferedReaderfor the given reader
- Throws:
- NullPointerException- if the input parameter is null
- Since:
- 2.5
 
- 
bufferReturns the given reader if it is already aBufferedReader, otherwise creates a BufferedReader from the given reader.- Parameters:
- reader- the reader to wrap or return (not null)
- size- the buffer size, if a new BufferedReader is created.
- Returns:
- the given reader or a new BufferedReaderfor the given reader
- Throws:
- NullPointerException- if the input parameter is null
- Since:
- 2.5
 
- 
bufferReturns the given Writer if it is already aBufferedWriter, otherwise creates a BufferedWriter from the given Writer.- Parameters:
- writer- the Writer to wrap or return (not null)
- Returns:
- the given Writer or a new BufferedWriterfor the given Writer
- Throws:
- NullPointerException- if the input parameter is null
- Since:
- 2.5
 
- 
bufferReturns the given Writer if it is already aBufferedWriter, otherwise creates a BufferedWriter from the given Writer.- Parameters:
- writer- the Writer to wrap or return (not null)
- size- the buffer size, if a new BufferedWriter is created.
- Returns:
- the given Writer or a new BufferedWriterfor the given Writer
- Throws:
- NullPointerException- if the input parameter is null
- Since:
- 2.5
 
- 
byteArrayReturns a new byte array of sizeDEFAULT_BUFFER_SIZE.- Returns:
- a new byte array of size DEFAULT_BUFFER_SIZE.
- Since:
- 2.9.0
 
- 
byteArrayReturns a new byte array of the given size. TODO Consider guarding or warning against large allocations...- Parameters:
- size- array size.
- Returns:
- a new byte array of the given size.
- Throws:
- NegativeArraySizeException- if the size is negative.
- Since:
- 2.9.0
 
- 
closeCloses the givenCloseableas a null-safe operation.- Parameters:
- closeable- The resource to close, may be null.
- Throws:
- IOException- if an I/O error occurs.
- Since:
- 2.7
 
- 
closeCloses the givenCloseables as null-safe operations.- Parameters:
- closeables- The resource(s) to close, may be null.
- Throws:
- IOExceptionList- if an I/O error occurs.
- Since:
- 2.8.0
 
- 
closeCloses the givenCloseableas a null-safe operation.- Parameters:
- closeable- The resource to close, may be null.
- consumer- Consume the IOException thrown by- Closeable.close().
- Throws:
- IOException- if an I/O error occurs.
- Since:
- 2.7
 
- 
closeCloses a URLConnection.- Parameters:
- conn- the connection to close.
- Since:
- 2.4
 
- 
closeQuietlyCloses aCloseableunconditionally.Equivalent to Closeable.close(), except any exceptions will be ignored. This is typically used in finally blocks.Example code: Closeable closeable = null; try { closeable = new FileReader("foo.txt"); // process closeable closeable.close(); } catch (Exception e) { // error handling } finally { IOUtils.closeQuietly(closeable); }Closing all streams: try { return IOUtils.copy(inputStream, outputStream); } finally { IOUtils.closeQuietly(inputStream); IOUtils.closeQuietly(outputStream); }Also consider using a try-with-resources statement where appropriate. - Parameters:
- closeable- the objects to close, may be null or already closed
- Since:
- 2.0
- See Also:
 
- 
closeQuietlyCloses aCloseableunconditionally.Equivalent to Closeable.close(), except any exceptions will be ignored.This is typically used in finally blocks to ensure that the closeable is closed even if an Exception was thrown before the normal close statement was reached. 
 It should not be used to replace the close statement(s) which should be present for the non-exceptional case.
 It is only intended to simplify tidying up where normal processing has already failed and reporting close failure as well is not necessary or useful.Example code: Closeable closeable = null; try { closeable = new FileReader("foo.txt"); // processing using the closeable; may throw an Exception closeable.close(); // Normal close - exceptions not ignored } catch (Exception e) { // error handling } finally { IOUtils.closeQuietly(closeable); // In case normal close was skipped due to Exception }Closing all streams: 
 try { return IOUtils.copy(inputStream, outputStream); } finally { IOUtils.closeQuietly(inputStream, outputStream); }Also consider using a try-with-resources statement where appropriate. - Parameters:
- closeables- the objects to close, may be null or already closed
- Since:
- 2.5
- See Also:
 
- 
closeQuietlyCloses the givenCloseableas a null-safe operation while consuming IOException by the givenconsumer.- Parameters:
- closeable- The resource to close, may be null.
- consumer- Consumes the Exception thrown by- Closeable.close().
- Since:
- 2.7
 
- 
closeQuietlyCloses anInputStreamunconditionally.Equivalent to InputStream.close(), except any exceptions will be ignored. This is typically used in finally blocks.Example code: byte[] data = new byte[1024]; InputStream in = null; try { in = new FileInputStream("foo.txt"); in.read(data); in.close(); //close errors are handled } catch (Exception e) { // error handling } finally { IOUtils.closeQuietly(in); }Also consider using a try-with-resources statement where appropriate. - Parameters:
- input- the InputStream to close, may be null or already closed
- See Also:
 
- 
closeQuietlyCloses an iterable ofCloseableunconditionally.Equivalent calling Closeable.close()on each element, except any exceptions will be ignored.- Parameters:
- closeables- the objects to close, may be null or already closed
- Since:
- 2.12.0
- See Also:
 
- 
closeQuietlyCloses anOutputStreamunconditionally.Equivalent to OutputStream.close(), except any exceptions will be ignored. This is typically used in finally blocks.Example code: byte[] data = "Hello, World".getBytes(); OutputStream out = null; try { out = new FileOutputStream("foo.txt"); out.write(data); out.close(); //close errors are handled } catch (IOException e) { // error handling } finally { IOUtils.closeQuietly(out); }Also consider using a try-with-resources statement where appropriate. - Parameters:
- output- the OutputStream to close, may be null or already closed
- See Also:
 
- 
closeQuietlyCloses anReaderunconditionally.Equivalent to Reader.close(), except any exceptions will be ignored. This is typically used in finally blocks.Example code: char[] data = new char[1024]; Reader in = null; try { in = new FileReader("foo.txt"); in.read(data); in.close(); //close errors are handled } catch (Exception e) { // error handling } finally { IOUtils.closeQuietly(in); }Also consider using a try-with-resources statement where appropriate. - Parameters:
- reader- the Reader to close, may be null or already closed
- See Also:
 
- 
closeQuietlyCloses aSelectorunconditionally.Equivalent to Selector.close(), except any exceptions will be ignored. This is typically used in finally blocks.Example code: Selector selector = null; try { selector = Selector.open(); // process socket } catch (Exception e) { // error handling } finally { IOUtils.closeQuietly(selector); }Also consider using a try-with-resources statement where appropriate. - Parameters:
- selector- the Selector to close, may be null or already closed
- Since:
- 2.2
- See Also:
 
- 
closeQuietlyCloses aServerSocketunconditionally.Equivalent to ServerSocket.close(), except any exceptions will be ignored. This is typically used in finally blocks.Example code: ServerSocket socket = null; try { socket = new ServerSocket(); // process socket socket.close(); } catch (Exception e) { // error handling } finally { IOUtils.closeQuietly(socket); }Also consider using a try-with-resources statement where appropriate. - Parameters:
- serverSocket- the ServerSocket to close, may be null or already closed
- Since:
- 2.2
- See Also:
 
- 
closeQuietlyCloses aSocketunconditionally.Equivalent to Socket.close(), except any exceptions will be ignored. This is typically used in finally blocks.Example code: Socket socket = null; try { socket = new Socket("http://www.foo.com/", 80); // process socket socket.close(); } catch (Exception e) { // error handling } finally { IOUtils.closeQuietly(socket); }Also consider using a try-with-resources statement where appropriate. - Parameters:
- socket- the Socket to close, may be null or already closed
- Since:
- 2.0
- See Also:
 
- 
closeQuietlyCloses a stream ofCloseableunconditionally.Equivalent calling Closeable.close()on each element, except any exceptions will be ignored.- Parameters:
- closeables- the objects to close, may be null or already closed
- Since:
- 2.12.0
- See Also:
 
- 
closeQuietlyCloses anWriterunconditionally.Equivalent to Writer.close(), except any exceptions will be ignored. This is typically used in finally blocks.Example code: Writer out = null; try { out = new StringWriter(); out.write("Hello World"); out.close(); //close errors are handled } catch (Exception e) { // error handling } finally { IOUtils.closeQuietly(out); }Also consider using a try-with-resources statement where appropriate. - Parameters:
- writer- the Writer to close, may be null or already closed
- See Also:
 
- 
consumeConsumes bytes from aInputStreamand ignores them.The buffer size is given by DEFAULT_BUFFER_SIZE.- Parameters:
- input- the- InputStreamto read.
- Returns:
- the number of bytes copied. or 0ifinput is null.
- Throws:
- NullPointerException- if the InputStream is- null.
- IOException- if an I/O error occurs.
- Since:
- 2.8.0
 
- 
consumeConsumes characters from aReaderand ignores them.The buffer size is given by DEFAULT_BUFFER_SIZE.- Parameters:
- input- the- Readerto read.
- Returns:
- the number of bytes copied. or 0ifinput is null.
- Throws:
- NullPointerException- if the Reader is- null.
- IOException- if an I/O error occurs.
- Since:
- 2.12.0
 
- 
contentEqualsCompares the contents of two Streams to determine if they are equal or not.This method buffers the input internally using BufferedInputStreamif they are not already buffered.- Parameters:
- input1- the first stream
- input2- the second stream
- Returns:
- true if the content of the streams are equal or they both don't exist, false otherwise
- Throws:
- IOException- if an I/O error occurs
 
- 
contentEqualsCompares the contents of two Readers to determine if they are equal or not.This method buffers the input internally using BufferedReaderif they are not already buffered.- Parameters:
- input1- the first reader
- input2- the second reader
- Returns:
- true if the content of the readers are equal or they both don't exist, false otherwise
- Throws:
- NullPointerException- if either input is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
contentEqualsIgnoreEOLpublic static boolean contentEqualsIgnoreEOL(Reader reader1, Reader reader2) throws UncheckedIOException Compares the contents of two Readers to determine if they are equal or not, ignoring EOL characters.This method buffers the input internally using BufferedReaderif they are not already buffered.- Parameters:
- reader1- the first reader
- reader2- the second reader
- Returns:
- true if the content of the readers are equal (ignoring EOL differences), false otherwise
- Throws:
- NullPointerException- if either input is null
- UncheckedIOException- if an I/O error occurs
- Since:
- 2.2
 
- 
copyCopies bytes from anInputStreamto anOutputStream.This method buffers the input internally, so there is no need to use a BufferedInputStream.Large streams (over 2GB) will return a bytes copied value of -1after the copy has completed since the correct number of bytes cannot be returned as an int. For large streams use thecopyLarge(InputStream, OutputStream)method.- Parameters:
- inputStream- the- InputStreamto read.
- outputStream- the- OutputStreamto write.
- Returns:
- the number of bytes copied, or -1 if greater than Integer.MAX_VALUE.
- Throws:
- NullPointerException- if the InputStream is- null.
- NullPointerException- if the OutputStream is- null.
- IOException- if an I/O error occurs.
- Since:
- 1.1
 
- 
copypublic static long copy(InputStream inputStream, OutputStream outputStream, int bufferSize) throws IOException Copies bytes from anInputStreamto anOutputStreamusing an internal buffer of the given size.This method buffers the input internally, so there is no need to use a BufferedInputStream.- Parameters:
- inputStream- the- InputStreamto read.
- outputStream- the- OutputStreamto write to
- bufferSize- the bufferSize used to copy from the input to the output
- Returns:
- the number of bytes copied.
- Throws:
- NullPointerException- if the InputStream is- null.
- NullPointerException- if the OutputStream is- null.
- IOException- if an I/O error occurs.
- Since:
- 2.5
 
- 
copyDeprecated.Usecopy(InputStream, Writer, Charset)insteadCopies bytes from anInputStreamto chars on aWriterusing the virtual machine'sdefault charset.This method buffers the input internally, so there is no need to use a BufferedInputStream.This method uses InputStreamReader.- Parameters:
- input- the- InputStreamto read
- writer- the- Writerto write to
- Throws:
- NullPointerException- if the input or output is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
copyCopies bytes from anInputStreamto chars on aWriterusing the specified character encoding.This method buffers the input internally, so there is no need to use a BufferedInputStream.This method uses InputStreamReader.- Parameters:
- input- the- InputStreamto read
- writer- the- Writerto write to
- inputCharset- the charset to use for the input stream, null means platform default
- Throws:
- NullPointerException- if the input or output is null
- IOException- if an I/O error occurs
- Since:
- 2.3
 
- 
copypublic static void copy(InputStream input, Writer writer, String inputCharsetName) throws IOException Copies bytes from anInputStreamto chars on aWriterusing the specified character encoding.This method buffers the input internally, so there is no need to use a BufferedInputStream.Character encoding names can be found at IANA. This method uses InputStreamReader.- Parameters:
- input- the- InputStreamto read
- writer- the- Writerto write to
- inputCharsetName- the name of the requested charset for the InputStream, null means platform default
- Throws:
- NullPointerException- if the input or output is null
- IOException- if an I/O error occurs
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 1.1
 
- 
copyCopies bytes from aByteArrayOutputStreamto aQueueInputStream.Unlike using JDK PipedInputStreamandPipedOutputStreamfor this, this solution works safely in a single thread environment.Example usage: ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); outputStream.writeBytes("hello world".getBytes(StandardCharsets.UTF_8)); InputStream inputStream = IOUtils.copy(outputStream);- Parameters:
- outputStream- the- ByteArrayOutputStreamto read.
- Returns:
- the QueueInputStreamfilled with the content of the outputStream.
- Throws:
- NullPointerException- if the- ByteArrayOutputStreamis- null.
- IOException- if an I/O error occurs.
- Since:
- 2.12
 
- 
copyCopies chars from aReaderto aAppendable.This method buffers the input internally, so there is no need to use a BufferedReader.Large streams (over 2GB) will return a chars copied value of -1after the copy has completed since the correct number of chars cannot be returned as an int. For large streams use thecopyLarge(Reader, Writer)method.- Parameters:
- reader- the- Readerto read
- output- the- Appendableto write to
- Returns:
- the number of characters copied, or -1 if > Integer.MAX_VALUE
- Throws:
- NullPointerException- if the input or output is null
- IOException- if an I/O error occurs
- Since:
- 2.7
 
- 
copyCopies chars from aReaderto anAppendable.This method uses the provided buffer, so there is no need to use a BufferedReader.- Parameters:
- reader- the- Readerto read
- output- the- Appendableto write to
- buffer- the buffer to be used for the copy
- Returns:
- the number of characters copied
- Throws:
- NullPointerException- if the input or output is null
- IOException- if an I/O error occurs
- Since:
- 2.7
 
- 
copyDeprecated.Usecopy(Reader, OutputStream, Charset)insteadCopies chars from aReaderto bytes on anOutputStreamusing the the virtual machine'sdefault charset, and calling flush.This method buffers the input internally, so there is no need to use a BufferedReader.Due to the implementation of OutputStreamWriter, this method performs a flush. This method uses OutputStreamWriter.- Parameters:
- reader- the- Readerto read
- output- the- OutputStreamto write to
- Throws:
- NullPointerException- if the input or output is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
copypublic static void copy(Reader reader, OutputStream output, Charset outputCharset) throws IOException Copies chars from aReaderto bytes on anOutputStreamusing the specified character encoding, and calling flush.This method buffers the input internally, so there is no need to use a BufferedReader.Due to the implementation of OutputStreamWriter, this method performs a flush. This method uses OutputStreamWriter.- Parameters:
- reader- the- Readerto read
- output- the- OutputStreamto write to
- outputCharset- the charset to use for the OutputStream, null means platform default
- Throws:
- NullPointerException- if the input or output is null
- IOException- if an I/O error occurs
- Since:
- 2.3
 
- 
copypublic static void copy(Reader reader, OutputStream output, String outputCharsetName) throws IOException Copies chars from aReaderto bytes on anOutputStreamusing the specified character encoding, and calling flush.This method buffers the input internally, so there is no need to use a BufferedReader.Character encoding names can be found at IANA. Due to the implementation of OutputStreamWriter, this method performs a flush. This method uses OutputStreamWriter.- Parameters:
- reader- the- Readerto read
- output- the- OutputStreamto write to
- outputCharsetName- the name of the requested charset for the OutputStream, null means platform default
- Throws:
- NullPointerException- if the input or output is null
- IOException- if an I/O error occurs
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 1.1
 
- 
copyCopies chars from aReaderto aWriter.This method buffers the input internally, so there is no need to use a BufferedReader.Large streams (over 2GB) will return a chars copied value of -1after the copy has completed since the correct number of chars cannot be returned as an int. For large streams use thecopyLarge(Reader, Writer)method.- Parameters:
- reader- the- Readerto read.
- writer- the- Writerto write.
- Returns:
- the number of characters copied, or -1 if > Integer.MAX_VALUE
- Throws:
- NullPointerException- if the input or output is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
copyCopies bytes from aURLto anOutputStream.This method buffers the input internally, so there is no need to use a BufferedInputStream.The buffer size is given by DEFAULT_BUFFER_SIZE.- Parameters:
- url- the- URLto read.
- file- the- OutputStreamto write.
- Returns:
- the number of bytes copied.
- Throws:
- NullPointerException- if the URL is- null.
- NullPointerException- if the OutputStream is- null.
- IOException- if an I/O error occurs.
- Since:
- 2.9.0
 
- 
copyCopies bytes from aURLto anOutputStream.This method buffers the input internally, so there is no need to use a BufferedInputStream.The buffer size is given by DEFAULT_BUFFER_SIZE.- Parameters:
- url- the- URLto read.
- outputStream- the- OutputStreamto write.
- Returns:
- the number of bytes copied.
- Throws:
- NullPointerException- if the URL is- null.
- NullPointerException- if the OutputStream is- null.
- IOException- if an I/O error occurs.
- Since:
- 2.9.0
 
- 
copyLargeCopies bytes from a large (over 2GB)InputStreamto anOutputStream.This method buffers the input internally, so there is no need to use a BufferedInputStream.The buffer size is given by DEFAULT_BUFFER_SIZE.- Parameters:
- inputStream- the- InputStreamto read.
- outputStream- the- OutputStreamto write.
- Returns:
- the number of bytes copied.
- Throws:
- NullPointerException- if the InputStream is- null.
- NullPointerException- if the OutputStream is- null.
- IOException- if an I/O error occurs.
- Since:
- 1.3
 
- 
copyLargepublic static long copyLarge(InputStream inputStream, OutputStream outputStream, byte[] buffer) throws IOException Copies bytes from a large (over 2GB)InputStreamto anOutputStream.This method uses the provided buffer, so there is no need to use a BufferedInputStream.- Parameters:
- inputStream- the- InputStreamto read.
- outputStream- the- OutputStreamto write.
- buffer- the buffer to use for the copy
- Returns:
- the number of bytes copied.
- Throws:
- NullPointerException- if the InputStream is- null.
- NullPointerException- if the OutputStream is- null.
- IOException- if an I/O error occurs.
- Since:
- 2.2
 
- 
copyLargepublic static long copyLarge(InputStream input, OutputStream output, long inputOffset, long length) throws IOException Copies some or all bytes from a large (over 2GB)InputStreamto anOutputStream, optionally skipping input bytes.This method buffers the input internally, so there is no need to use a BufferedInputStream.Note that the implementation uses The buffer size is given byskip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.DEFAULT_BUFFER_SIZE.- Parameters:
- input- the- InputStreamto read.
- output- the- OutputStreamto write.
- inputOffset- number of bytes to skip from input before copying, these bytes are ignored.
- length- number of bytes to copy.
- Returns:
- the number of bytes copied.
- Throws:
- NullPointerException- if the input or output is null.
- IOException- if an I/O error occurs.
- Since:
- 2.2
 
- 
copyLargepublic static long copyLarge(InputStream input, OutputStream output, long inputOffset, long length, byte[] buffer) throws IOException Copies some or all bytes from a large (over 2GB)InputStreamto anOutputStream, optionally skipping input bytes.This method uses the provided buffer, so there is no need to use a BufferedInputStream.Note that the implementation uses skip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.- Parameters:
- input- the- InputStreamto read.
- output- the- OutputStreamto write.
- inputOffset- number of bytes to skip from input before copying, these bytes are ignored.
- length- number of bytes to copy.
- buffer- the buffer to use for the copy.
- Returns:
- the number of bytes copied.
- Throws:
- NullPointerException- if the input or output is null.
- IOException- if an I/O error occurs.
- Since:
- 2.2
 
- 
copyLargeCopies chars from a large (over 2GB)Readerto aWriter.This method buffers the input internally, so there is no need to use a BufferedReader.The buffer size is given by DEFAULT_BUFFER_SIZE.- Parameters:
- reader- the- Readerto source.
- writer- the- Writerto target.
- Returns:
- the number of characters copied
- Throws:
- NullPointerException- if the input or output is null
- IOException- if an I/O error occurs
- Since:
- 1.3
 
- 
copyLargeCopies chars from a large (over 2GB)Readerto aWriter.This method uses the provided buffer, so there is no need to use a BufferedReader.- Parameters:
- reader- the- Readerto source.
- writer- the- Writerto target.
- buffer- the buffer to be used for the copy
- Returns:
- the number of characters copied
- Throws:
- NullPointerException- if the input or output is null
- IOException- if an I/O error occurs
- Since:
- 2.2
 
- 
copyLargepublic static long copyLarge(Reader reader, Writer writer, long inputOffset, long length) throws IOException Copies some or all chars from a large (over 2GB)InputStreamto anOutputStream, optionally skipping input chars.This method buffers the input internally, so there is no need to use a BufferedReader.The buffer size is given by DEFAULT_BUFFER_SIZE.- Parameters:
- reader- the- Readerto read
- writer- the- Writerto write to
- inputOffset- number of chars to skip from input before copying -ve values are ignored
- length- number of chars to copy. -ve means all
- Returns:
- the number of chars copied
- Throws:
- NullPointerException- if the input or output is null
- IOException- if an I/O error occurs
- Since:
- 2.2
 
- 
copyLargepublic static long copyLarge(Reader reader, Writer writer, long inputOffset, long length, char[] buffer) throws IOException Copies some or all chars from a large (over 2GB)InputStreamto anOutputStream, optionally skipping input chars.This method uses the provided buffer, so there is no need to use a BufferedReader.- Parameters:
- reader- the- Readerto read
- writer- the- Writerto write to
- inputOffset- number of chars to skip from input before copying -ve values are ignored
- length- number of chars to copy. -ve means all
- buffer- the buffer to be used for the copy
- Returns:
- the number of chars copied
- Throws:
- NullPointerException- if the input or output is null
- IOException- if an I/O error occurs
- Since:
- 2.2
 
- 
lengthReturns the length of the given array in a null-safe manner.- Parameters:
- array- an array or null
- Returns:
- the array length, or 0 if the given array is null.
- Since:
- 2.7
 
- 
lengthReturns the length of the given array in a null-safe manner.- Parameters:
- array- an array or null
- Returns:
- the array length, or 0 if the given array is null.
- Since:
- 2.7
 
- 
lengthReturns the length of the given CharSequence in a null-safe manner.- Parameters:
- csq- a CharSequence or null
- Returns:
- the CharSequence length, or 0 if the given CharSequence is null.
- Since:
- 2.7
 
- 
lengthReturns the length of the given array in a null-safe manner.- Parameters:
- array- an array or null
- Returns:
- the array length, or 0 if the given array is null.
- Since:
- 2.7
 
- 
lineIteratorReturns an Iterator for the lines in anInputStream, using the character encoding specified (or default encoding if null).LineIteratorholds a reference to the openInputStreamspecified here. When you have finished with the iterator you should close the stream to free internal resources. This can be done by using a try-with-resources block, closing the stream directly, or by callingLineIterator.close().The recommended usage pattern is: try { LineIterator it = IOUtils.lineIterator(stream, charset); while (it.hasNext()) { String line = it.nextLine(); /// do something with line } } finally { IOUtils.closeQuietly(stream); }- Parameters:
- input- the- InputStreamto read, not null
- charset- the charset to use, null means platform default
- Returns:
- an Iterator of the lines in the reader, never null
- Throws:
- IllegalArgumentException- if the input is null
- Since:
- 2.3
 
- 
lineIteratorReturns an Iterator for the lines in anInputStream, using the character encoding specified (or default encoding if null).LineIteratorholds a reference to the openInputStreamspecified here. When you have finished with the iterator you should close the stream to free internal resources. This can be done by using a try-with-resources block, closing the stream directly, or by callingLineIterator.close().The recommended usage pattern is: try { LineIterator it = IOUtils.lineIterator(stream, StandardCharsets.UTF_8.name()); while (it.hasNext()) { String line = it.nextLine(); /// do something with line } } finally { IOUtils.closeQuietly(stream); }- Parameters:
- input- the- InputStreamto read, not null
- charsetName- the encoding to use, null means platform default
- Returns:
- an Iterator of the lines in the reader, never null
- Throws:
- IllegalArgumentException- if the input is null
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 1.2
 
- 
lineIteratorReturns an Iterator for the lines in aReader.LineIteratorholds a reference to the openReaderspecified here. When you have finished with the iterator you should close the reader to free internal resources. This can be done by using a try-with-resources block, closing the reader directly, or by callingLineIterator.close().The recommended usage pattern is: try { LineIterator it = IOUtils.lineIterator(reader); while (it.hasNext()) { String line = it.nextLine(); /// do something with line } } finally { IOUtils.closeQuietly(reader); }- Parameters:
- reader- the- Readerto read, not null
- Returns:
- an Iterator of the lines in the reader, never null
- Throws:
- NullPointerException- if the reader is null
- Since:
- 1.2
 
- 
readReads bytes from an input stream. This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for subclasses ofInputStream.- Parameters:
- input- where to read input from
- buffer- destination
- Returns:
- actual length read; may be less than requested if EOF was reached
- Throws:
- IOException- if a read error occurs
- Since:
- 2.2
 
- 
readReads bytes from an input stream. This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for subclasses ofInputStream.- Parameters:
- input- where to read input
- buffer- destination
- offset- initial offset into buffer
- length- length to read, must be >= 0
- Returns:
- actual length read; may be less than requested if EOF was reached
- Throws:
- IllegalArgumentException- if length is negative
- IOException- if a read error occurs
- Since:
- 2.2
 
- 
readReads bytes from a ReadableByteChannel.This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for subclasses of ReadableByteChannel.- Parameters:
- input- the byte channel to read
- buffer- byte buffer destination
- Returns:
- the actual length read; may be less than requested if EOF was reached
- Throws:
- IOException- if a read error occurs
- Since:
- 2.5
 
- 
readReads characters from an input character stream. This implementation guarantees that it will read as many characters as possible before giving up; this may not always be the case for subclasses ofReader.- Parameters:
- reader- where to read input from
- buffer- destination
- Returns:
- actual length read; may be less than requested if EOF was reached
- Throws:
- IOException- if a read error occurs
- Since:
- 2.2
 
- 
readReads characters from an input character stream. This implementation guarantees that it will read as many characters as possible before giving up; this may not always be the case for subclasses ofReader.- Parameters:
- reader- where to read input from
- buffer- destination
- offset- initial offset into buffer
- length- length to read, must be >= 0
- Returns:
- actual length read; may be less than requested if EOF was reached
- Throws:
- IllegalArgumentException- if length is negative
- IOException- if a read error occurs
- Since:
- 2.2
 
- 
readFullyReads the requested number of bytes or fail if there are not enough left.This allows for the possibility that InputStream.read(byte[], int, int)may not read as many bytes as requested (most likely because of reaching EOF).- Parameters:
- input- where to read input from
- buffer- destination
- Throws:
- IOException- if there is a problem reading the file
- IllegalArgumentException- if length is negative
- EOFException- if the number of bytes read was incorrect
- Since:
- 2.2
 
- 
readFullypublic static void readFully(InputStream input, byte[] buffer, int offset, int length) throws IOException Reads the requested number of bytes or fail if there are not enough left.This allows for the possibility that InputStream.read(byte[], int, int)may not read as many bytes as requested (most likely because of reaching EOF).- Parameters:
- input- where to read input from
- buffer- destination
- offset- initial offset into buffer
- length- length to read, must be >= 0
- Throws:
- IOException- if there is a problem reading the file
- IllegalArgumentException- if length is negative
- EOFException- if the number of bytes read was incorrect
- Since:
- 2.2
 
- 
readFullyReads the requested number of bytes or fail if there are not enough left.This allows for the possibility that InputStream.read(byte[], int, int)may not read as many bytes as requested (most likely because of reaching EOF).- Parameters:
- input- where to read input from
- length- length to read, must be >= 0
- Returns:
- the bytes read from input
- Throws:
- IOException- if there is a problem reading the file
- IllegalArgumentException- if length is negative
- EOFException- if the number of bytes read was incorrect
- Since:
- 2.5
 
- 
readFullyReads the requested number of bytes or fail if there are not enough left.This allows for the possibility that ReadableByteChannel.read(ByteBuffer)may not read as many bytes as requested (most likely because of reaching EOF).- Parameters:
- input- the byte channel to read
- buffer- byte buffer destination
- Throws:
- IOException- if there is a problem reading the file
- EOFException- if the number of bytes read was incorrect
- Since:
- 2.5
 
- 
readFullyReads the requested number of characters or fail if there are not enough left.This allows for the possibility that Reader.read(char[], int, int)may not read as many characters as requested (most likely because of reaching EOF).- Parameters:
- reader- where to read input from
- buffer- destination
- Throws:
- IOException- if there is a problem reading the file
- IllegalArgumentException- if length is negative
- EOFException- if the number of characters read was incorrect
- Since:
- 2.2
 
- 
readFullypublic static void readFully(Reader reader, char[] buffer, int offset, int length) throws IOException Reads the requested number of characters or fail if there are not enough left.This allows for the possibility that Reader.read(char[], int, int)may not read as many characters as requested (most likely because of reaching EOF).- Parameters:
- reader- where to read input from
- buffer- destination
- offset- initial offset into buffer
- length- length to read, must be >= 0
- Throws:
- IOException- if there is a problem reading the file
- IllegalArgumentException- if length is negative
- EOFException- if the number of characters read was incorrect
- Since:
- 2.2
 
- 
readLinesGets the contents of aCharSequenceas a list of Strings, one entry per line.- Parameters:
- csq- the- CharSequenceto read, not null
- Returns:
- the list of Strings, never null
- Throws:
- UncheckedIOException- if an I/O error occurs
- Since:
- 2.18.0
 
- 
readLinesDeprecated.UsereadLines(InputStream, Charset)insteadGets the contents of anInputStreamas a list of Strings, one entry per line, using the virtual machine'sdefault charset.This method buffers the input internally, so there is no need to use a BufferedInputStream.- Parameters:
- input- the- InputStreamto read, not null
- Returns:
- the list of Strings, never null
- Throws:
- NullPointerException- if the input is null
- UncheckedIOException- if an I/O error occurs
- Since:
- 1.1
 
- 
readLinespublic static List<String> readLines(InputStream input, Charset charset) throws UncheckedIOException Gets the contents of anInputStreamas a list of Strings, one entry per line, using the specified character encoding.This method buffers the input internally, so there is no need to use a BufferedInputStream.- Parameters:
- input- the- InputStreamto read, not null
- charset- the charset to use, null means platform default
- Returns:
- the list of Strings, never null
- Throws:
- NullPointerException- if the input is null
- UncheckedIOException- if an I/O error occurs
- Since:
- 2.3
 
- 
readLinespublic static List<String> readLines(InputStream input, String charsetName) throws UncheckedIOException Gets the contents of anInputStreamas a list of Strings, one entry per line, using the specified character encoding.Character encoding names can be found at IANA. This method buffers the input internally, so there is no need to use a BufferedInputStream.- Parameters:
- input- the- InputStreamto read, not null
- charsetName- the name of the requested charset, null means platform default
- Returns:
- the list of Strings, never null
- Throws:
- NullPointerException- if the input is null
- UncheckedIOException- if an I/O error occurs
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 1.1
 
- 
readLinesGets the contents of aReaderas a list of Strings, one entry per line.This method buffers the input internally, so there is no need to use a BufferedReader.- Parameters:
- reader- the- Readerto read, not null
- Returns:
- the list of Strings, never null
- Throws:
- NullPointerException- if the input is null
- UncheckedIOException- if an I/O error occurs
- Since:
- 1.1
 
- 
resourceToByteArrayGets the contents of a resource as a byte array.Delegates to resourceToByteArray(String, null).- Parameters:
- name- The resource name.
- Returns:
- the requested byte array
- Throws:
- IOException- if an I/O error occurs or the resource is not found.
- Since:
- 2.6
- See Also:
 
- 
resourceToByteArrayGets the contents of a resource as a byte array.Delegates to resourceToURL(String, ClassLoader).- Parameters:
- name- The resource name.
- classLoader- the class loader that the resolution of the resource is delegated to
- Returns:
- the requested byte array
- Throws:
- IOException- if an I/O error occurs or the resource is not found.
- Since:
- 2.6
- See Also:
 
- 
resourceToStringGets the contents of a resource as a String using the specified character encoding.Delegates to resourceToString(String, Charset, null).- Parameters:
- name- The resource name.
- charset- the charset to use, null means platform default
- Returns:
- the requested String
- Throws:
- IOException- if an I/O error occurs or the resource is not found.
- Since:
- 2.6
- See Also:
 
- 
resourceToStringpublic static String resourceToString(String name, Charset charset, ClassLoader classLoader) throws IOException Gets the contents of a resource as a String using the specified character encoding.Delegates to resourceToURL(String, ClassLoader).- Parameters:
- name- The resource name.
- charset- the Charset to use, null means platform default
- classLoader- the class loader that the resolution of the resource is delegated to
- Returns:
- the requested String
- Throws:
- IOException- if an I/O error occurs.
- Since:
- 2.6
- See Also:
 
- 
resourceToURLGets a URL pointing to the given resource.Delegates to resourceToURL(String, null).- Parameters:
- name- The resource name.
- Returns:
- A URL object for reading the resource.
- Throws:
- IOException- if the resource is not found.
- Since:
- 2.6
 
- 
resourceToURLGets a URL pointing to the given resource.If the classLoaderis not null, callClassLoader.getResource(String), otherwise callIOUtils.class.getResource(name).- Parameters:
- name- The resource name.
- classLoader- Delegate to this class loader if not null
- Returns:
- A URL object for reading the resource.
- Throws:
- IOException- if the resource is not found.
- Since:
- 2.6
 
- 
skipSkips bytes from an input byte stream. This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for skip() implementations in subclasses ofInputStream.Note that the implementation uses InputStream.read(byte[], int, int)rather than delegating toInputStream.skip(long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of bytes are skipped.- Parameters:
- input- byte stream to skip
- skip- number of bytes to skip.
- Returns:
- number of bytes actually skipped.
- Throws:
- IOException- if there is a problem reading the file
- IllegalArgumentException- if toSkip is negative
- Since:
- 2.0
- See Also:
 
- 
skippublic static long skip(InputStream input, long skip, Supplier<byte[]> skipBufferSupplier) throws IOException Skips bytes from an input byte stream.Intended for special cases when customization of the temporary buffer is needed because, for example, a nested input stream has requirements for the bytes read. For example, when using InflaterInputStreams from multiple threads.This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for skip() implementations in subclasses of InputStream.Note that the implementation uses InputStream.read(byte[], int, int)rather than delegating toInputStream.skip(long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of bytes are skipped.- Parameters:
- input- byte stream to skip
- skip- number of bytes to skip.
- skipBufferSupplier- Supplies the buffer to use for reading.
- Returns:
- number of bytes actually skipped.
- Throws:
- IOException- if there is a problem reading the file
- IllegalArgumentException- if toSkip is negative
- Since:
- 2.14.0
- See Also:
 
- 
skipSkips bytes from a ReadableByteChannel. This implementation guarantees that it will read as many bytes as possible before giving up.- Parameters:
- input- ReadableByteChannel to skip
- toSkip- number of bytes to skip.
- Returns:
- number of bytes actually skipped.
- Throws:
- IOException- if there is a problem reading the ReadableByteChannel
- IllegalArgumentException- if toSkip is negative
- Since:
- 2.5
 
- 
skipSkips characters from an input character stream. This implementation guarantees that it will read as many characters as possible before giving up; this may not always be the case for skip() implementations in subclasses ofReader.Note that the implementation uses Reader.read(char[], int, int)rather than delegating toReader.skip(long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.- Parameters:
- reader- character stream to skip
- toSkip- number of characters to skip.
- Returns:
- number of characters actually skipped.
- Throws:
- IOException- if there is a problem reading the file
- IllegalArgumentException- if toSkip is negative
- Since:
- 2.0
- See Also:
 
- 
skipFullySkips the requested number of bytes or fail if there are not enough left.This allows for the possibility that InputStream.skip(long)may not skip as many bytes as requested (most likely because of reaching EOF).Note that the implementation uses skip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.- Parameters:
- input- stream to skip
- toSkip- the number of bytes to skip
- Throws:
- IOException- if there is a problem reading the file
- IllegalArgumentException- if toSkip is negative
- EOFException- if the number of bytes skipped was incorrect
- Since:
- 2.0
- See Also:
 
- 
skipFullypublic static void skipFully(InputStream input, long toSkip, Supplier<byte[]> skipBufferSupplier) throws IOException Skips the requested number of bytes or fail if there are not enough left.Intended for special cases when customization of the temporary buffer is needed because, for example, a nested input stream has requirements for the bytes read. For example, when using InflaterInputStreams from multiple threads.This allows for the possibility that InputStream.skip(long)may not skip as many bytes as requested (most likely because of reaching EOF).Note that the implementation uses skip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.- Parameters:
- input- stream to skip
- toSkip- the number of bytes to skip
- skipBufferSupplier- Supplies the buffer to use for reading.
- Throws:
- IOException- if there is a problem reading the file
- IllegalArgumentException- if toSkip is negative
- EOFException- if the number of bytes skipped was incorrect
- Since:
- 2.14.0
- See Also:
 
- 
skipFullySkips the requested number of bytes or fail if there are not enough left.- Parameters:
- input- ReadableByteChannel to skip
- toSkip- the number of bytes to skip
- Throws:
- IOException- if there is a problem reading the ReadableByteChannel
- IllegalArgumentException- if toSkip is negative
- EOFException- if the number of bytes skipped was incorrect
- Since:
- 2.5
 
- 
skipFullySkips the requested number of characters or fail if there are not enough left.This allows for the possibility that Reader.skip(long)may not skip as many characters as requested (most likely because of reaching EOF).Note that the implementation uses skip(Reader, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.- Parameters:
- reader- stream to skip
- toSkip- the number of characters to skip
- Throws:
- IOException- if there is a problem reading the file
- IllegalArgumentException- if toSkip is negative
- EOFException- if the number of characters skipped was incorrect
- Since:
- 2.0
- See Also:
 
- 
toBufferedInputStreamFetches entire contents of anInputStreamand represent same data as result InputStream.This method is useful where, - Source InputStream is slow.
- It has network resources associated, so we cannot keep it open for long time.
- It has network timeout associated.
 It can be used in favor of toByteArray(InputStream), since it avoids unnecessary allocation and copy of byte[].
 This method buffers the input internally, so there is no need to use aBufferedInputStream.- Parameters:
- input- Stream to be fully buffered.
- Returns:
- A fully buffered stream.
- Throws:
- IOException- if an I/O error occurs.
- Since:
- 2.0
 
- 
toBufferedInputStreamFetches entire contents of anInputStreamand represent same data as result InputStream.This method is useful where, - Source InputStream is slow.
- It has network resources associated, so we cannot keep it open for long time.
- It has network timeout associated.
 It can be used in favor of toByteArray(InputStream), since it avoids unnecessary allocation and copy of byte[].
 This method buffers the input internally, so there is no need to use aBufferedInputStream.- Parameters:
- input- Stream to be fully buffered.
- size- the initial buffer size
- Returns:
- A fully buffered stream.
- Throws:
- IOException- if an I/O error occurs.
- Since:
- 2.5
 
- 
toBufferedReaderReturns the given reader if it is aBufferedReader, otherwise creates a BufferedReader from the given reader.- Parameters:
- reader- the reader to wrap or return (not null)
- Returns:
- the given reader or a new BufferedReaderfor the given reader
- Throws:
- NullPointerException- if the input parameter is null
- Since:
- 2.2
- See Also:
 
- 
toBufferedReaderReturns the given reader if it is aBufferedReader, otherwise creates a BufferedReader from the given reader.- Parameters:
- reader- the reader to wrap or return (not null)
- size- the buffer size, if a new BufferedReader is created.
- Returns:
- the given reader or a new BufferedReaderfor the given reader
- Throws:
- NullPointerException- if the input parameter is null
- Since:
- 2.5
- See Also:
 
- 
toByteArrayGets the contents of anInputStreamas abyte[].This method buffers the input internally, so there is no need to use a BufferedInputStream.- Parameters:
- inputStream- the- InputStreamto read.
- Returns:
- the requested byte array.
- Throws:
- NullPointerException- if the InputStream is- null.
- IOException- if an I/O error occurs or reading more than- Integer.MAX_VALUEoccurs.
 
- 
toByteArrayGets the contents of anInputStreamas abyte[]. Use this method instead oftoByteArray(InputStream)whenInputStreamsize is known.- Parameters:
- input- the- InputStreamto read.
- size- the size of- InputStreamto read, where 0 <- size<= length of input stream.
- Returns:
- byte [] of length size.
- Throws:
- IOException- if an I/O error occurs or- InputStreamlength is smaller than parameter- size.
- IllegalArgumentException- if- sizeis less than zero.
- Since:
- 2.1
 
- 
toByteArrayGets contents of anInputStreamas abyte[]. Use this method instead oftoByteArray(InputStream)whenInputStreamsize is known. NOTE: the method checks that the length can safely be cast to an int without truncation before usingtoByteArray(InputStream, int)to read into the byte array. (Arrays can have no more than Integer.MAX_VALUE entries anyway)- Parameters:
- input- the- InputStreamto read
- size- the size of- InputStreamto read, where 0 <- size<= min(Integer.MAX_VALUE, length of input stream).
- Returns:
- byte [] the requested byte array, of length size
- Throws:
- IOException- if an I/O error occurs or- InputStreamlength is less than- size
- IllegalArgumentException- if size is less than zero or size is greater than Integer.MAX_VALUE
- Since:
- 2.1
- See Also:
 
- 
toByteArrayDeprecated.UsetoByteArray(Reader, Charset)insteadGets the contents of aReaderas abyte[]using the virtual machine'sdefault charset.This method buffers the input internally, so there is no need to use a BufferedReader.- Parameters:
- reader- the- Readerto read
- Returns:
- the requested byte array
- Throws:
- NullPointerException- if the input is null
- IOException- if an I/O error occurs
 
- 
toByteArrayGets the contents of aReaderas abyte[]using the specified character encoding.This method buffers the input internally, so there is no need to use a BufferedReader.- Parameters:
- reader- the- Readerto read
- charset- the charset to use, null means platform default
- Returns:
- the requested byte array
- Throws:
- NullPointerException- if the input is null
- IOException- if an I/O error occurs
- Since:
- 2.3
 
- 
toByteArrayGets the contents of aReaderas abyte[]using the specified character encoding.Character encoding names can be found at IANA. This method buffers the input internally, so there is no need to use a BufferedReader.- Parameters:
- reader- the- Readerto read
- charsetName- the name of the requested charset, null means platform default
- Returns:
- the requested byte array
- Throws:
- NullPointerException- if the input is null
- IOException- if an I/O error occurs
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 1.1
 
- 
toByteArrayDeprecated.UseString.getBytes()insteadGets the contents of aStringas abyte[]using the virtual machine'sdefault charset.This is the same as String.getBytes().- Parameters:
- input- the- Stringto convert
- Returns:
- the requested byte array
- Throws:
- NullPointerException- if the input is null
 
- 
toByteArrayGets the contents of aURIas abyte[].- Parameters:
- uri- the- URIto read
- Returns:
- the requested byte array
- Throws:
- NullPointerException- if the uri is null
- IOException- if an I/O exception occurs
- Since:
- 2.4
 
- 
toByteArrayGets the contents of aURLas abyte[].- Parameters:
- url- the- URLto read
- Returns:
- the requested byte array
- Throws:
- NullPointerException- if the input is null
- IOException- if an I/O exception occurs
- Since:
- 2.4
 
- 
toByteArrayGets the contents of aURLConnectionas abyte[].- Parameters:
- urlConnection- the- URLConnectionto read.
- Returns:
- the requested byte array.
- Throws:
- NullPointerException- if the urlConn is null.
- IOException- if an I/O exception occurs.
- Since:
- 2.4
 
- 
toCharArrayDeprecated.UsetoCharArray(InputStream, Charset)insteadGets the contents of anInputStreamas a character array using the virtual machine'sdefault charset.This method buffers the input internally, so there is no need to use a BufferedInputStream.- Parameters:
- inputStream- the- InputStreamto read
- Returns:
- the requested character array
- Throws:
- NullPointerException- if the input is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
toCharArrayGets the contents of anInputStreamas a character array using the specified character encoding.This method buffers the input internally, so there is no need to use a BufferedInputStream.- Parameters:
- inputStream- the- InputStreamto read
- charset- the charset to use, null means platform default
- Returns:
- the requested character array
- Throws:
- NullPointerException- if the input is null
- IOException- if an I/O error occurs
- Since:
- 2.3
 
- 
toCharArrayGets the contents of anInputStreamas a character array using the specified character encoding.Character encoding names can be found at IANA. This method buffers the input internally, so there is no need to use a BufferedInputStream.- Parameters:
- inputStream- the- InputStreamto read
- charsetName- the name of the requested charset, null means platform default
- Returns:
- the requested character array
- Throws:
- NullPointerException- if the input is null
- IOException- if an I/O error occurs
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 1.1
 
- 
toCharArrayGets the contents of aReaderas a character array.This method buffers the input internally, so there is no need to use a BufferedReader.- Parameters:
- reader- the- Readerto read
- Returns:
- the requested character array
- Throws:
- NullPointerException- if the input is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
toInputStreamDeprecated.UsetoInputStream(CharSequence, Charset)insteadConverts the specified CharSequence to an input stream, encoded as bytes using the virtual machine'sdefault charset.- Parameters:
- input- the CharSequence to convert
- Returns:
- an input stream
- Since:
- 2.0
 
- 
toInputStreamConverts the specified CharSequence to an input stream, encoded as bytes using the specified character encoding.- Parameters:
- input- the CharSequence to convert
- charset- the charset to use, null means platform default
- Returns:
- an input stream
- Since:
- 2.3
 
- 
toInputStreamConverts the specified CharSequence to an input stream, encoded as bytes using the specified character encoding.Character encoding names can be found at IANA. - Parameters:
- input- the CharSequence to convert
- charsetName- the name of the requested charset, null means platform default
- Returns:
- an input stream
- Throws:
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 2.0
 
- 
toInputStreamDeprecated.UsetoInputStream(String, Charset)insteadConverts the specified string to an input stream, encoded as bytes using the virtual machine'sdefault charset.- Parameters:
- input- the string to convert
- Returns:
- an input stream
- Since:
- 1.1
 
- 
toInputStreamConverts the specified string to an input stream, encoded as bytes using the specified character encoding.- Parameters:
- input- the string to convert
- charset- the charset to use, null means platform default
- Returns:
- an input stream
- Since:
- 2.3
 
- 
toInputStreamConverts the specified string to an input stream, encoded as bytes using the specified character encoding.Character encoding names can be found at IANA. - Parameters:
- input- the string to convert
- charsetName- the name of the requested charset, null means platform default
- Returns:
- an input stream
- Throws:
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 1.1
 
- 
toStringDeprecated.UseString(byte[])insteadGets the contents of abyte[]as a String using the virtual machine'sdefault charset.- Parameters:
- input- the byte array to read
- Returns:
- the requested String
- Throws:
- NullPointerException- if the input is null
 
- 
toStringGets the contents of abyte[]as a String using the specified character encoding.Character encoding names can be found at IANA. - Parameters:
- input- the byte array to read
- charsetName- the name of the requested charset, null means platform default
- Returns:
- the requested String
- Throws:
- NullPointerException- if the input is null
 
- 
toStringDeprecated.UsetoString(InputStream, Charset)insteadGets the contents of anInputStreamas a String using the virtual machine'sdefault charset.This method buffers the input internally, so there is no need to use a BufferedInputStream.- Parameters:
- input- the- InputStreamto read
- Returns:
- the requested String
- Throws:
- NullPointerException- if the input is null
- IOException- if an I/O error occurs
 
- 
toStringGets the contents of anInputStreamas a String using the specified character encoding.This method buffers the input internally, so there is no need to use a BufferedInputStream.- Parameters:
- input- the- InputStreamto read
- charset- the charset to use, null means platform default
- Returns:
- the requested String
- Throws:
- NullPointerException- if the input is null
- IOException- if an I/O error occurs
- Since:
- 2.3
 
- 
toStringGets the contents of anInputStreamas a String using the specified character encoding.Character encoding names can be found at IANA. This method buffers the input internally, so there is no need to use a BufferedInputStream.- Parameters:
- input- the- InputStreamto read
- charsetName- the name of the requested charset, null means platform default
- Returns:
- the requested String
- Throws:
- NullPointerException- if the input is null
- IOException- if an I/O error occurs
- UnsupportedCharsetException- if the encoding is not supported
 
- 
toStringGets the contents of anInputStreamfrom a supplier as a String using the specified character encoding.This method buffers the input internally, so there is no need to use a BufferedInputStream.- Parameters:
- input- supplies the- InputStreamto read
- charset- the charset to use, null means platform default
- Returns:
- the requested String
- Throws:
- NullPointerException- if the input is null
- IOException- if an I/O error occurs
- Since:
- 2.12.0
 
- 
toStringpublic static String toString(IOSupplier<InputStream> input, Charset charset, IOSupplier<String> defaultString) throws IOException Gets the contents of anInputStreamfrom a supplier as a String using the specified character encoding.This method buffers the input internally, so there is no need to use a BufferedInputStream.- Parameters:
- input- supplies the- InputStreamto read
- charset- the charset to use, null means platform default
- defaultString- the default return value if the supplier or its value is null.
- Returns:
- the requested String
- Throws:
- NullPointerException- if the input is null
- IOException- if an I/O error occurs
- Since:
- 2.12.0
 
- 
toStringGets the contents of aReaderas a String.This method buffers the input internally, so there is no need to use a BufferedReader.- Parameters:
- reader- the- Readerto read
- Returns:
- the requested String
- Throws:
- NullPointerException- if the input is null
- IOException- if an I/O error occurs
 
- 
toStringDeprecated.UsetoString(URI, Charset)insteadGets the contents at the given URI using the virtual machine'sdefault charset.- Parameters:
- uri- The URI source.
- Returns:
- The contents of the URL as a String.
- Throws:
- IOException- if an I/O exception occurs.
- Since:
- 2.1
 
- 
toStringGets the contents at the given URI.- Parameters:
- uri- The URI source.
- encoding- The encoding name for the URL contents.
- Returns:
- The contents of the URL as a String.
- Throws:
- IOException- if an I/O exception occurs.
- Since:
- 2.3.
 
- 
toStringGets the contents at the given URI.- Parameters:
- uri- The URI source.
- charsetName- The encoding name for the URL contents.
- Returns:
- The contents of the URL as a String.
- Throws:
- IOException- if an I/O exception occurs.
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 2.1
 
- 
toStringDeprecated.UsetoString(URL, Charset)insteadGets the contents at the given URL using the virtual machine'sdefault charset.- Parameters:
- url- The URL source.
- Returns:
- The contents of the URL as a String.
- Throws:
- IOException- if an I/O exception occurs.
- Since:
- 2.1
 
- 
toStringGets the contents at the given URL.- Parameters:
- url- The URL source.
- encoding- The encoding name for the URL contents.
- Returns:
- The contents of the URL as a String.
- Throws:
- IOException- if an I/O exception occurs.
- Since:
- 2.3
 
- 
toStringGets the contents at the given URL.- Parameters:
- url- The URL source.
- charsetName- The encoding name for the URL contents.
- Returns:
- The contents of the URL as a String.
- Throws:
- IOException- if an I/O exception occurs.
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 2.1
 
- 
writeWrites bytes from abyte[]to anOutputStream.- Parameters:
- data- the byte array to write, do not modify during output, null ignored
- output- the- OutputStreamto write to
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
writeDeprecated.Usewrite(byte[], Writer, Charset)insteadWrites bytes from abyte[]to chars on aWriterusing the virtual machine'sdefault charset.This method uses String(byte[]).- Parameters:
- data- the byte array to write, do not modify during output, null ignored
- writer- the- Writerto write to
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
writeWrites bytes from abyte[]to chars on aWriterusing the specified character encoding.This method uses String(byte[], String).- Parameters:
- data- the byte array to write, do not modify during output, null ignored
- writer- the- Writerto write to
- charset- the charset to use, null means platform default
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 2.3
 
- 
writeWrites bytes from abyte[]to chars on aWriterusing the specified character encoding.Character encoding names can be found at IANA. This method uses String(byte[], String).- Parameters:
- data- the byte array to write, do not modify during output, null ignored
- writer- the- Writerto write to
- charsetName- the name of the requested charset, null means platform default
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 1.1
 
- 
writeDeprecated.Usewrite(char[], OutputStream, Charset)insteadWrites chars from achar[]to bytes on anOutputStream.This method uses the virtual machine's default charset.- Parameters:
- data- the char array to write, do not modify during output, null ignored
- output- the- OutputStreamto write to
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
writeWrites chars from achar[]to bytes on anOutputStreamusing the specified character encoding.This method uses String(char[])andString.getBytes(String).- Parameters:
- data- the char array to write, do not modify during output, null ignored
- output- the- OutputStreamto write to
- charset- the charset to use, null means platform default
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 2.3
 
- 
writeWrites chars from achar[]to bytes on anOutputStreamusing the specified character encoding.Character encoding names can be found at IANA. This method uses String(char[])andString.getBytes(String).- Parameters:
- data- the char array to write, do not modify during output, null ignored
- output- the- OutputStreamto write to
- charsetName- the name of the requested charset, null means platform default
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 1.1
 
- 
writeWrites chars from achar[]to aWriter- Parameters:
- data- the char array to write, do not modify during output, null ignored
- writer- the- Writerto write to
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
writeDeprecated.Usewrite(CharSequence, OutputStream, Charset)insteadWrites chars from aCharSequenceto bytes on anOutputStreamusing the virtual machine'sdefault charset.This method uses String.getBytes().- Parameters:
- data- the- CharSequenceto write, null ignored
- output- the- OutputStreamto write to
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 2.0
 
- 
writepublic static void write(CharSequence data, OutputStream output, Charset charset) throws IOException Writes chars from aCharSequenceto bytes on anOutputStreamusing the specified character encoding.This method uses String.getBytes(String).- Parameters:
- data- the- CharSequenceto write, null ignored
- output- the- OutputStreamto write to
- charset- the charset to use, null means platform default
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 2.3
 
- 
writepublic static void write(CharSequence data, OutputStream output, String charsetName) throws IOException Writes chars from aCharSequenceto bytes on anOutputStreamusing the specified character encoding.Character encoding names can be found at IANA. This method uses String.getBytes(String).- Parameters:
- data- the- CharSequenceto write, null ignored
- output- the- OutputStreamto write to
- charsetName- the name of the requested charset, null means platform default
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 2.0
 
- 
writeWrites chars from aCharSequenceto aWriter.- Parameters:
- data- the- CharSequenceto write, null ignored
- writer- the- Writerto write to
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 2.0
 
- 
writeDeprecated.Usewrite(String, OutputStream, Charset)insteadWrites chars from aStringto bytes on anOutputStreamusing the virtual machine'sdefault charset.This method uses String.getBytes().- Parameters:
- data- the- Stringto write, null ignored
- output- the- OutputStreamto write to
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
writeWrites chars from aStringto bytes on anOutputStreamusing the specified character encoding.This method uses String.getBytes(String).- Parameters:
- data- the- Stringto write, null ignored
- output- the- OutputStreamto write to
- charset- the charset to use, null means platform default
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 2.3
 
- 
writeWrites chars from aStringto bytes on anOutputStreamusing the specified character encoding.Character encoding names can be found at IANA. This method uses String.getBytes(String).- Parameters:
- data- the- Stringto write, null ignored
- output- the- OutputStreamto write to
- charsetName- the name of the requested charset, null means platform default
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 1.1
 
- 
write- Parameters:
- data- the- Stringto write, null ignored
- writer- the- Writerto write to
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
writeDeprecated.Writes chars from aStringBufferto bytes on anOutputStreamusing the default character encoding of the platform.This method uses String.getBytes().- Parameters:
- data- the- StringBufferto write, null ignored
- output- the- OutputStreamto write to
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
write@Deprecated public static void write(StringBuffer data, OutputStream output, String charsetName) throws IOException Deprecated.Writes chars from aStringBufferto bytes on anOutputStreamusing the specified character encoding.Character encoding names can be found at IANA. This method uses String.getBytes(String).- Parameters:
- data- the- StringBufferto write, null ignored
- output- the- OutputStreamto write to
- charsetName- the name of the requested charset, null means platform default
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 1.1
 
- 
writeDeprecated.Writes chars from aStringBufferto aWriter.- Parameters:
- data- the- StringBufferto write, null ignored
- writer- the- Writerto write to
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
writeChunkedWrites bytes from abyte[]to anOutputStreamusing chunked writes. This is intended for writing very large byte arrays which might otherwise cause excessive memory usage if the native code has to allocate a copy.- Parameters:
- data- the byte array to write, do not modify during output, null ignored
- output- the- OutputStreamto write to
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 2.5
 
- 
writeChunkedWrites chars from achar[]to aWriterusing chunked writes. This is intended for writing very large byte arrays which might otherwise cause excessive memory usage if the native code has to allocate a copy.- Parameters:
- data- the char array to write, do not modify during output, null ignored
- writer- the- Writerto write to
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 2.5
 
- 
writeLines@Deprecated public static void writeLines(Collection<?> lines, String lineEnding, OutputStream output) throws IOException Deprecated.Writes theObject.toString()value of each item in a collection to anOutputStreamline by line, using the virtual machine'sdefault charsetand the specified line ending.- Parameters:
- lines- the lines to write, null entries produce blank lines
- lineEnding- the line separator to use, null is system default
- output- the- OutputStreamto write to, not null, not closed
- Throws:
- NullPointerException- if the output is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
writeLinespublic static void writeLines(Collection<?> lines, String lineEnding, OutputStream output, Charset charset) throws IOException Writes theObject.toString()value of each item in a collection to anOutputStreamline by line, using the specified character encoding and the specified line ending.UTF-16 is written big-endian with no byte order mark. For little-endian, use UTF-16LE. For a BOM, write it to the stream before calling this method. - Parameters:
- lines- the lines to write, null entries produce blank lines
- lineEnding- the line separator to use, null is system default
- output- the- OutputStreamto write to, not null, not closed
- charset- the charset to use, null means platform default
- Throws:
- NullPointerException- if output is null
- IOException- if an I/O error occurs
- Since:
- 2.3
 
- 
writeLinespublic static void writeLines(Collection<?> lines, String lineEnding, OutputStream output, String charsetName) throws IOException Writes theObject.toString()value of each item in a collection to anOutputStreamline by line, using the specified character encoding and the specified line ending.Character encoding names can be found at IANA. - Parameters:
- lines- the lines to write, null entries produce blank lines
- lineEnding- the line separator to use, null is system default
- output- the- OutputStreamto write to, not null, not closed
- charsetName- the name of the requested charset, null means platform default
- Throws:
- NullPointerException- if the output is null
- IOException- if an I/O error occurs
- UnsupportedCharsetException- if the encoding is not supported
- Since:
- 1.1
 
- 
writeLinespublic static void writeLines(Collection<?> lines, String lineEnding, Writer writer) throws IOException Writes theObject.toString()value of each item in a collection to aWriterline by line, using the specified line ending.- Parameters:
- lines- the lines to write, null entries produce blank lines
- lineEnding- the line separator to use, null is system default
- writer- the- Writerto write to, not null, not closed
- Throws:
- NullPointerException- if the input is null
- IOException- if an I/O error occurs
- Since:
- 1.1
 
- 
writerReturns the given Appendable if it is already aWriter, otherwise creates a Writer wrapper around the given Appendable.- Parameters:
- appendable- the Appendable to wrap or return (not null)
- Returns:
- the given Appendable or a Writer wrapper around the given Appendable
- Throws:
- NullPointerException- if the input parameter is null
- Since:
- 2.7
 
 
- 
System.lineSeparator().