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.
