Japt (Java Optimizer) Bytecode Optimizer for Java

Bytecode optimization tool to ease development and deployment of Java

The tool provides the following functionality and technologies:

• escape analysis on a per method-invocation basis
• static control flow analysis finding the entry points into an application or library
• removal of unwanted attributes from Java™ class files or adding specialized attributes to class files
• creation or rewrite of stackmaps for Java class files
• verification of Java class files, providing more feedback than the runtime verifier
• auto-generation of classes to load other classes within the same archive
• specific remapping of method invocations
• specific rewrites of bytecodes
• obfuscation of class, field and method names
• assembler and disassembler of bytecodes
• static control flow analysis for removal of unused methods, classes, fields
• static control flow analysis that splits an application into archives according to thread accessibility
• insertion of checkcasts to allow the runtime verifier to avoid extra class loads for quicker startup performance
• separating methods unused at startup into separate classes for quicker startup performance
• listing the fields/methods missing from a Java lib profile (such as Java 8 compact profiles) that are required by application
• instrumentation of bytecode
• inlining of methods, and/or merging inner classes into their respective outer classes, for class file size reduction

Documentation

Users of Japt can refer to the user documentation while developers should consult the developer documentation.