i2pplus

Pack200 (pack200/)

Fork of the Pack200 compression format for JAR files. Extracted from OpenJDK just before its removal in Java 14.

Why Pack200?

Pack200 achieves 60-80% compression on JAR files by:

• Analyzing bytecode across all classes
• Sharing constant pools
• Applying predictions

This made it ideal for router updates over I2P (bandwidth-constrained). Development I2P+ updates use Pack200-compressed JARs.

Status

Pack200 was removed in Java 14 (2019). This fork re-adds Pack200 support for Java 14 and later, enabling compressed I2P+ updates across all supported Java versions.

Packages

• io.pack200 - Packer, unpacker, archive format

Building

ant -f java/build.xml