Class DeferredFileOutputStream
- All Implemented Interfaces:
- Closeable,- Flushable,- AutoCloseable
 To build an instance, use DeferredFileOutputStream.Builder.
 
 The caller is responsible for deleting the output file (getFile(), getPath()) created by a DeferredFileOutputStream when the caller only
 configured a prefix.
 
 The caller is responsible for deleting the output file passed to a constructor or builder through DeferredFileOutputStream.Builder.setOutputFile(File) or
 DeferredFileOutputStream.Builder.setOutputFile(Path).
 
This class originated in FileUpload processing. In this use case, you do not know in advance the size of the file being uploaded. If the file is small you want to store it in memory (for speed), but if the file is large you want to store it to file (to avoid memory issues).
- See Also:
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Nested Class SummaryNested Classes
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Constructor SummaryConstructorsConstructorDescriptionDeferredFileOutputStream(int threshold, int initialBufferSize, File outputFile) Deprecated.DeferredFileOutputStream(int threshold, int initialBufferSize, String prefix, String suffix, File directory) Deprecated.DeferredFileOutputStream(int threshold, File outputFile) Deprecated.DeferredFileOutputStream(int threshold, String prefix, String suffix, File directory) Deprecated.
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Method SummaryModifier and TypeMethodDescriptionbuilder()Constructs a newDeferredFileOutputStream.Builder.voidclose()Closes underlying output stream, and mark this as closedbyte[]getData()Gets the data for this output stream as an array of bytes, assuming that the data has been retained in memory.getFile()Gets either the output File specified in the constructor or the temporary File created or null.getPath()Gets either the output Path specified in the constructor or the temporary Path created or null.protected OutputStreamDeprecated.booleanTests whether or not the data for this output stream has been retained in memory.protected voidSwitches the underlying output stream from a memory based stream to one that is backed by disk.Converts the current contents of this byte stream to anInputStream.voidwriteTo(OutputStream outputStream) Writes the data from this output stream to the specified output stream, after it has been closed.Methods inherited from class org.apache.commons.io.output.ThresholdingOutputStreamcheckThreshold, flush, getByteCount, getOutputStream, getThreshold, isThresholdExceeded, resetByteCount, setByteCount, write, write, write
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Constructor Details- 
DeferredFileOutputStreamDeprecated.Constructs an instance of this class which will trigger an event at the specified threshold, and save data to a file beyond that point. The initial buffer size will default to 1024 bytes which is ByteArrayOutputStream's default buffer size.- Parameters:
- threshold- The number of bytes at which to trigger an event.
- outputFile- The file to which data is saved beyond the threshold.
 
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DeferredFileOutputStreamDeprecated.Constructs an instance of this class which will trigger an event at the specified threshold, and save data to a file beyond that point.- Parameters:
- threshold- The number of bytes at which to trigger an event.
- initialBufferSize- The initial size of the in memory buffer.
- outputFile- The file to which data is saved beyond the threshold.
- Since:
- 2.5
 
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DeferredFileOutputStream@Deprecated public DeferredFileOutputStream(int threshold, int initialBufferSize, String prefix, String suffix, File directory) Deprecated.Constructs an instance of this class which will trigger an event at the specified threshold, and save data to a temporary file beyond that point.- Parameters:
- threshold- The number of bytes at which to trigger an event.
- initialBufferSize- The initial size of the in memory buffer.
- prefix- Prefix to use for the temporary file.
- suffix- Suffix to use for the temporary file.
- directory- Temporary file directory.
- Since:
- 2.5
 
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DeferredFileOutputStream@Deprecated public DeferredFileOutputStream(int threshold, String prefix, String suffix, File directory) Deprecated.Constructs an instance of this class which will trigger an event at the specified threshold, and save data to a temporary file beyond that point. The initial buffer size will default to 32 bytes which is ByteArrayOutputStream's default buffer size.- Parameters:
- threshold- The number of bytes at which to trigger an event.
- prefix- Prefix to use for the temporary file.
- suffix- Suffix to use for the temporary file.
- directory- Temporary file directory.
- Since:
- 1.4
 
 
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Method Details- 
builderConstructs a newDeferredFileOutputStream.Builder.- Returns:
- a new DeferredFileOutputStream.Builder.
- Since:
- 2.12.0
 
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closeCloses underlying output stream, and mark this as closed- Specified by:
- closein interface- AutoCloseable
- Specified by:
- closein interface- Closeable
- Overrides:
- closein class- ThresholdingOutputStream
- Throws:
- IOException- if an error occurs.
 
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getDataGets the data for this output stream as an array of bytes, assuming that the data has been retained in memory. If the data was written to disk, this method returnsnull.- Returns:
- The data for this output stream, or nullif no such data is available.
 
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getFileGets either the output File specified in the constructor or the temporary File created or null.If the constructor specifying the File is used then it returns that same output File, even when threshold has not been reached. If constructor specifying a temporary File prefix/suffix is used then the temporary File created once the threshold is reached is returned if the threshold was not reached then nullis returned.- Returns:
- The File for this output stream, or nullif no such File exists.
 
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getPathGets either the output Path specified in the constructor or the temporary Path created or null.If the constructor specifying the file is used then it returns that same output Path, even when threshold has not been reached. If constructor specifying a temporary Path prefix/suffix is used then the temporary Path created once the threshold is reached is returned if the threshold was not reached then nullis returned.- Returns:
- The Path for this output stream, or nullif no such Path exists.
- Since:
- 2.14.0
 
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getStreamDeprecated.Gets the current output stream. This may be memory based or disk based, depending on the current state with respect to the threshold.- Overrides:
- getStreamin class- ThresholdingOutputStream
- Returns:
- The underlying output stream.
- Throws:
- IOException- if an error occurs.
 
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isInMemoryTests whether or not the data for this output stream has been retained in memory.- Returns:
- trueif the data is available in memory;- falseotherwise.
 
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thresholdReachedSwitches the underlying output stream from a memory based stream to one that is backed by disk. This is the point at which we realize that too much data is being written to keep in memory, so we elect to switch to disk-based storage.- Overrides:
- thresholdReachedin class- ThresholdingOutputStream
- Throws:
- IOException- if an error occurs.
 
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toInputStreamConverts the current contents of this byte stream to anInputStream. If the data for this output stream has been retained in memory, the returned stream is backed by buffers ofthisstream, avoiding memory allocation and copy, thus saving space and time.
 Otherwise, the returned stream will be one that is created from the data that has been committed to disk.- Returns:
- the current contents of this output stream.
- Throws:
- IOException- if this stream is not yet closed or an error occurs.
- Since:
- 2.9.0
- See Also:
 
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writeToWrites the data from this output stream to the specified output stream, after it has been closed.- Parameters:
- outputStream- output stream to write to.
- Throws:
- NullPointerException- if the OutputStream is- null.
- IOException- if this stream is not yet closed or an error occurs.
 
 
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builder(),DeferredFileOutputStream.Builder, andDeferredFileOutputStream.Builder.get()