Class CopyUtils
InputStream, Reader,
 String and byte[]) and destinations
 (OutputStream, Writer, String and
 byte[]).
 
 Unless otherwise noted, these copy methods do not
 flush or close the streams. Often doing so would require making non-portable
 assumptions about the streams' origin and further use. This means that both
 streams' close() methods must be called after copying. if one
 omits this step, then the stream resources (sockets, file descriptors) are
 released when the associated Stream is garbage-collected. It is not a good
 idea to rely on this mechanism. For a good overview of the distinction
 between "memory management" and "resource management", see
 this
 UnixReview article.
 
 For byte-to-char methods, a copy variant allows the encoding
 to be selected (otherwise the platform default is used). We would like to
 encourage you to always specify the encoding because relying on the platform
 default can lead to unexpected results.
 
 We don't provide special variants for the copy methods that
 let you specify the buffer size because in modern VMs the impact on speed
 seems to be minimal. We're using a default buffer size of 4 KB.
 
 The copy methods use an internal buffer when copying. It is
 therefore advisable not to deliberately wrap the stream arguments
 to the copy methods in Buffered* streams. For
 example, don't do the following:
 
copy( new BufferedInputStream( in ), new BufferedOutputStream( out ) );The rationale is as follows:
 Imagine that an InputStream's read() is a very expensive operation, which
 would usually suggest wrapping in a BufferedInputStream. The
 BufferedInputStream works by issuing infrequent
 InputStream.read(byte[] b, int off, int len) requests on the
 underlying InputStream, to fill an internal buffer, from which further
 read requests can inexpensively get their data (until the buffer
 runs out).
 
 However, the copy methods do the same thing, keeping an
 internal buffer, populated by
 InputStream.read(byte[] b, int off, int len) requests. Having two
 buffers (or three if the destination stream is also buffered) is pointless,
 and the unnecessary buffer management hurts performance slightly (about 3%,
 according to some simple experiments).
 
Behold, intrepid explorers; a map of this class:
       Method      Input               Output          Dependency
       ------      -----               ------          -------
 1     copy        InputStream         OutputStream    (primitive)
 2     copy        Reader              Writer          (primitive)
 3     copy        InputStream         Writer          2
 4     copy        Reader              OutputStream    2
 5     copy        String              OutputStream    2
 6     copy        String              Writer          (trivial)
 7     copy        byte[]              Writer          3
 8     copy        byte[]              OutputStream    (trivial)
 
 Note that only the first two methods shuffle bytes; the rest use these two, or (if possible) copy using native Java copy methods. As there are method variants to specify the encoding, each row may correspond to up to 2 methods.
Provenance: Excalibur.
- 
Constructor SummaryConstructors
- 
Method SummaryModifier and TypeMethodDescriptionstatic voidcopy(byte[] input, OutputStream output) Deprecated.Copies bytes from abyte[]to anOutputStream.static voidDeprecated.Usecopy(byte[], Writer, String)insteadstatic voidDeprecated.Copies and convert bytes from abyte[]to chars on aWriter, using the specified encoding.static intcopy(InputStream input, OutputStream output) Deprecated.Copies bytes from anInputStreamto anOutputStream.static voidcopy(InputStream input, Writer output) Deprecated.Usecopy(InputStream, Writer, String)insteadstatic voidcopy(InputStream input, Writer output, String encoding) Deprecated.Copies and convert bytes from anInputStreamto chars on aWriter, using the specified encoding.static voidcopy(Reader input, OutputStream output) Deprecated.Usecopy(Reader, OutputStream, String)insteadstatic voidcopy(Reader input, OutputStream output, String encoding) Deprecated.static intstatic voidcopy(String input, OutputStream output) Deprecated.Usecopy(String, OutputStream, String)insteadstatic voidcopy(String input, OutputStream output, String encoding) Deprecated.static void
- 
Constructor Details- 
CopyUtilsDeprecated.TODO Make private in 3.0.Instances should NOT be constructed in standard programming.
 
- 
- 
Method Details- 
copyDeprecated.Copies bytes from abyte[]to anOutputStream.- Parameters:
- input- the byte array to read from
- output- the- OutputStreamto write to
- Throws:
- IOException- In case of an I/O problem
 
- 
copyDeprecated.Usecopy(byte[], Writer, String)insteadCopies and convert bytes from abyte[]to chars on aWriter. The platform's default encoding is used for the byte-to-char conversion.- Parameters:
- input- the byte array to read from
- output- the- Writerto write to
- Throws:
- IOException- In case of an I/O problem
 
- 
copyDeprecated.Copies and convert bytes from abyte[]to chars on aWriter, using the specified encoding.- Parameters:
- input- the byte array to read from
- output- the- Writerto write to
- encoding- The name of a supported character encoding. See the IANA Charset Registry for a list of valid encoding types.
- Throws:
- IOException- In case of an I/O problem
 
- 
copyDeprecated.Copies bytes from anInputStreamto anOutputStream.- Parameters:
- input- the- InputStreamto read from
- output- the- OutputStreamto write to
- Returns:
- the number of bytes copied
- Throws:
- IOException- In case of an I/O problem
 
- 
copyDeprecated.Usecopy(InputStream, Writer, String)insteadCopies and convert bytes from anInputStreamto chars on aWriter.This method uses the virtual machine's default charsetfor byte-to-char conversion.- Parameters:
- input- the- InputStreamto read from
- output- the- Writerto write to
- Throws:
- IOException- In case of an I/O problem
 
- 
copyDeprecated.Copies and convert bytes from anInputStreamto chars on aWriter, using the specified encoding.- Parameters:
- input- the- InputStreamto read from
- output- the- Writerto write to
- encoding- The name of a supported character encoding. See the IANA Charset Registry for a list of valid encoding types.
- Throws:
- IOException- In case of an I/O problem
 
- 
copyDeprecated.Usecopy(Reader, OutputStream, String)insteadSerialize chars from aReaderto bytes on anOutputStream, and flush theOutputStream.This method uses the virtual machine's default charsetfor byte-to-char conversion.- Parameters:
- input- the- Readerto read from
- output- the- OutputStreamto write to
- Throws:
- IOException- In case of an I/O problem
 
- 
copyDeprecated.- Parameters:
- input- the- Readerto read from
- output- the- OutputStreamto write to
- encoding- The name of a supported character encoding. See the IANA Charset Registry for a list of valid encoding types.
- Throws:
- IOException- In case of an I/O problem
- Since:
- 2.5
 
- 
copyDeprecated.- Parameters:
- input- the- Readerto read from
- output- the- Writerto write to
- Returns:
- the number of characters copied
- Throws:
- IOException- In case of an I/O problem
 
- 
copyDeprecated.Usecopy(String, OutputStream, String)insteadSerialize chars from aStringto bytes on anOutputStream, and flush theOutputStream.This method uses the virtual machine's default charsetfor byte-to-char conversion.- Parameters:
- input- the- Stringto read from
- output- the- OutputStreamto write to
- Throws:
- IOException- In case of an I/O problem
 
- 
copyDeprecated.- Parameters:
- input- the- Stringto read from
- output- the- OutputStreamto write to
- encoding- The name of a supported character encoding. See the IANA Charset Registry for a list of valid encoding types.
- Throws:
- IOException- In case of an I/O problem
- Since:
- 2.5
 
- 
copyDeprecated.- Parameters:
- input- the- Stringto read from
- output- the- Writerto write to
- Throws:
- IOException- In case of an I/O problem
 
 
-