| Documentation Contents

# Jar and Zip Enhancements

This page summarizes enhancements to the jar and zip support provided in JDK 6.

## API changes

Two new compressed streams have been added:

- `java.util.zip.DeflaterInputStream`: Data read from this stream is compressed.
- `java.util.zip.InflaterOutputStream`: Data written to this stream is decompressed.

For example, these can be useful if a client wants to send compressed data over a network. The data can be compressed into packets with `DeflaterInputStream`, and those packets written over the network connection. The receiving end then reads the compressed packets from the network connection, and decompresses them by writing to an `InflaterOutputStream`.

## Implementation changes

On all platforms, zip files can contain more than 64k entries.

On Windows, some limitations have been removed:

- File names longer than 256 characters are now supported.
- The limitation of just over 2,000 simultaneously open zip files has been removed.

## Changes to the `jar` command

There are two changes to the behavior of the `jar` command:

- The timestamps of extracted files are those listed in the archive, instead of the time of extraction.
- When creating a jar, it is possible to specify the entry point for stand-alone applications bundled into an executable jar file. The 'e' option specifies the application entry point by creating or overriding the Main-Class attribute value in the jar file's manifest.

Copyright © 1995-2010 Sun Microsystems, Inc. All Rights Reserved. Please send comments using this Feedback page. | Java Technology