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/OpenJDK 21

Class DeflaterOutputStream

All Implemented Interfaces:
Closeable, Flushable, AutoCloseable
Direct Known Subclasses:
GZIPOutputStream, ZipOutputStream
public class DeflaterOutputStream extends FilterOutputStream
This class implements an output stream filter for compressing data in the "deflate" compression format. It is also used as the basis for other types of compression filters, such as GZIPOutputStream.
Since:
1.1
See Also:

Field Summary

Modifier and Type Field Description
protected byte[] buf
Output buffer for writing compressed data.
protected Deflater def
Compressor for this stream.

Fields declared in class java.io.FilterOutputStream

out

Constructor Summary

Constructor Description
DeflaterOutputStream(OutputStream out)
Creates a new output stream with a default compressor and buffer size.
DeflaterOutputStream(OutputStream out, boolean syncFlush)
Creates a new output stream with a default compressor, a default buffer size and the specified flush mode.
DeflaterOutputStream(OutputStream out, Deflater def)
Creates a new output stream with the specified compressor and a default buffer size.
DeflaterOutputStream(OutputStream out, Deflater def, boolean syncFlush)
Creates a new output stream with the specified compressor, flush mode and a default buffer size.
DeflaterOutputStream(OutputStream out, Deflater def, int size)
Creates a new output stream with the specified compressor and buffer size.
DeflaterOutputStream(OutputStream out, Deflater def, int size, boolean syncFlush)
Creates a new output stream with the specified compressor, buffer size and flush mode.

Method Summary

Modifier and Type Method Description
void close()
Writes remaining compressed data to the output stream and closes the underlying stream.
protected void deflate()
Writes next block of compressed data to the output stream.
void finish()
Finishes writing compressed data to the output stream without closing the underlying stream.
void flush()
Flushes the compressed output stream.
void write(byte[] b, int off, int len)
Writes an array of bytes to the compressed output stream.
void write(int b)
Writes a byte to the compressed output stream.

Methods declared in class java.io.FilterOutputStream

write

Methods declared in class java.io.OutputStream

nullOutputStream

Methods declared in class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

def

protected Deflater def
Compressor for this stream.

buf

protected byte[] buf
Output buffer for writing compressed data.

Constructor Details

DeflaterOutputStream

public DeflaterOutputStream(OutputStream out, Deflater def, int size, boolean syncFlush)
Creates a new output stream with the specified compressor, buffer size and flush mode.
Parameters:
out - the output stream
def - the compressor ("deflater")
size - the output buffer size
syncFlush - if true the flush() method of this instance flushes the compressor with flush mode Deflater.SYNC_FLUSH before flushing the output stream, otherwise only flushes the output stream
Throws:
IllegalArgumentException - if size <= 0
Since:
1.7

DeflaterOutputStream

public DeflaterOutputStream(OutputStream out, Deflater def, int size)
Creates a new output stream with the specified compressor and buffer size.

The new output stream instance is created as if by invoking the 4-argument constructor DeflaterOutputStream(out, def, size, false).

Parameters:
out - the output stream
def - the compressor ("deflater")
size - the output buffer size
Throws:
IllegalArgumentException - if size <= 0

DeflaterOutputStream

public DeflaterOutputStream(OutputStream out, Deflater def, boolean syncFlush)
Creates a new output stream with the specified compressor, flush mode and a default buffer size.
Parameters:
out - the output stream
def - the compressor ("deflater")
syncFlush - if true the flush() method of this instance flushes the compressor with flush mode Deflater.SYNC_FLUSH before flushing the output stream, otherwise only flushes the output stream
Since:
1.7

DeflaterOutputStream

public DeflaterOutputStream(OutputStream out, Deflater def)
Creates a new output stream with the specified compressor and a default buffer size.

The new output stream instance is created as if by invoking the 3-argument constructor DeflaterOutputStream(out, def, false).

Parameters:
out - the output stream
def - the compressor ("deflater")

DeflaterOutputStream

public DeflaterOutputStream(OutputStream out, boolean syncFlush)
Creates a new output stream with a default compressor, a default buffer size and the specified flush mode.
Parameters:
out - the output stream
syncFlush - if true the flush() method of this instance flushes the compressor with flush mode Deflater.SYNC_FLUSH before flushing the output stream, otherwise only flushes the output stream
Since:
1.7

DeflaterOutputStream

public DeflaterOutputStream(OutputStream out)
Creates a new output stream with a default compressor and buffer size.

The new output stream instance is created as if by invoking the 2-argument constructor DeflaterOutputStream(out, false).

Parameters:
out - the output stream

Method Details

write

public void write(int b) throws IOException
Writes a byte to the compressed output stream. This method will block until the byte can be written.
Overrides:
write in class FilterOutputStream
Parameters:
b - the byte to be written
Throws:
IOException - if an I/O error has occurred

write

public void write(byte[] b, int off, int len) throws IOException
Writes an array of bytes to the compressed output stream. This method will block until all the bytes are written.
Overrides:
write in class FilterOutputStream
Parameters:
b - the data to be written
off - the start offset of the data
len - the length of the data
Throws:
IOException - if an I/O error has occurred
See Also:

finish

public void finish() throws IOException
Finishes writing compressed data to the output stream without closing the underlying stream. Use this method when applying multiple filters in succession to the same output stream.
Throws:
IOException - if an I/O error has occurred

close

public void close() throws IOException
Writes remaining compressed data to the output stream and closes the underlying stream.
Specified by:
close in interface AutoCloseable
Specified by:
close in interface Closeable
Overrides:
close in class FilterOutputStream
Throws:
IOException - if an I/O error has occurred
See Also:

deflate

protected void deflate() throws IOException
Writes next block of compressed data to the output stream.
Throws:
IOException - if an I/O error has occurred

flush

public void flush() throws IOException
Flushes the compressed output stream. If syncFlush is true when this compressed output stream is constructed, this method first flushes the underlying compressor with the flush mode Deflater.SYNC_FLUSH to force all pending data to be flushed out to the output stream and then flushes the output stream. Otherwise this method only flushes the output stream without flushing the compressor.
Specified by:
flush in interface Flushable
Overrides:
flush in class FilterOutputStream
Throws:
IOException - if an I/O error has occurred
Since:
1.7
See Also:

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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/util/zip/DeflaterOutputStream.html