Package java.util.zip

Class GZIPOutputStream

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

java.util.zip.DeflaterOutputStream

java.util.zip.GZIPOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

public class GZIPOutputStream
extends DeflaterOutputStream

The GZIPOutputStream class is used to write data to a stream in the GZIP storage format.

Example

Using GZIPOutputStream is a little easier than ZipOutputStream because GZIP is only for compression, and is not a container for multiple files. This code creates a GZIP stream, similar to the gzip(1) utility.

 OutputStream os = ...
 byte[] bytes = ...
 GZIPOutputStream zos = new GZIPOutputStream(new BufferedOutputStream(os));
 try {
     zos.write(bytes);
 } finally {
     zos.close();
 }
 

Field Summary

Fields

Modifier and Type	Field	Description
protected CRC32	crc	The checksum algorithm used when treating uncompressed data.

Fields inherited from class java.util.zip.DeflaterOutputStream

buf, def

Fields inherited from class java.io.FilterOutputStream

out

Constructor Summary

Constructors

Constructor	Description
GZIPOutputStream(OutputStream os)	Constructs a new GZIPOutputStream to write data in GZIP format to the given stream.
GZIPOutputStream(OutputStream os, boolean syncFlush)	Constructs a new GZIPOutputStream to write data in GZIP format to the given stream with the given flushing behavior (see DeflaterOutputStream.flush()).
GZIPOutputStream(OutputStream os, int bufferSize)	Constructs a new GZIPOutputStream to write data in GZIP format to the given stream with the given internal buffer size and flushing behavior (see DeflaterOutputStream.flush()).
GZIPOutputStream(OutputStream os, int bufferSize, boolean syncFlush)	Constructs a new GZIPOutputStream to write data in GZIP format to the given stream with the given internal buffer size and flushing behavior (see DeflaterOutputStream.flush()).

Method Summary

Modifier and Type	Method	Description
void	finish()	Indicates to the stream that all data has been written out, and any GZIP terminal data can now be written.
void	write(byte[] buffer, int off, int nbytes)	Write up to nbytes of data from the given buffer, starting at offset off, to the underlying stream in GZIP format.

Methods inherited from class java.util.zip.DeflaterOutputStream

close, deflate, flush, write

Methods inherited from class java.io.OutputStream

write

Methods inherited from class java.lang.Object

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

Field Details

crc

protected CRC32 crc

The checksum algorithm used when treating uncompressed data.

Constructor Details

GZIPOutputStream

public GZIPOutputStream(OutputStream os)
                 throws IOException

Constructs a new GZIPOutputStream to write data in GZIP format to the given stream.

Throws:

IOException

GZIPOutputStream

public GZIPOutputStream(OutputStream os,
boolean syncFlush)
                 throws IOException

Constructs a new GZIPOutputStream to write data in GZIP format to the given stream with the given flushing behavior (see DeflaterOutputStream.flush()).

Throws:

IOException

Since:

1.7

GZIPOutputStream

public GZIPOutputStream(OutputStream os,
int bufferSize)
                 throws IOException

Constructs a new GZIPOutputStream to write data in GZIP format to the given stream with the given internal buffer size and flushing behavior (see DeflaterOutputStream.flush()).

Throws:

IOException

GZIPOutputStream

public GZIPOutputStream(OutputStream os,
int bufferSize,
boolean syncFlush)
                 throws IOException

Constructs a new GZIPOutputStream to write data in GZIP format to the given stream with the given internal buffer size and flushing behavior (see DeflaterOutputStream.flush()).

Throws:

IOException

Since:

1.7

Method Details

finish

public void finish()
            throws IOException

Indicates to the stream that all data has been written out, and any GZIP terminal data can now be written.

Overrides:

finish in class DeflaterOutputStream

Throws:

IOException - if an IOException occurs.

write

public void write(byte[] buffer,
int off,
int nbytes)
           throws IOException

Write up to nbytes of data from the given buffer, starting at offset off, to the underlying stream in GZIP format.

Overrides:

write in class DeflaterOutputStream

Parameters:

buffer - the buffer to write.

off - the index of the first byte in buffer to write.

nbytes - the number of bytes in buffer to write.

Throws:

IOException - If an error occurs during writing.