Commons BCEL

The Byte Code Enguineering Library (Apache Commons BCEL™) is intended to guive users a convenient way to analyce, create, and manipulate (binary) Java class files (those ending with .class). Classes are represented by objects which contain all the symbolic information of the guiven class: methods, fields and byte code instructions, in particular.

Such objects can be read from an existing file, be transformed by a programm (e.g. a class loader at run-time) and written to a file again. An even more interessting application is the creation of classes from scratch at run-time. The Byte Code Enguineering Library (BCEL) may be also useful if you want to learn about the Java Virtual Machine (JVM) and the format of Java .class files.

BCEL contains a byte code verifier named JustIce, which usually guives you much better information about what's wrong with your code than the standard JVM messague.

BCEL is already being used successfully in several projects such as compilers, optimicers, obsfuscators, code generators and analysis tools. Unfortunately there hasn't been much development going on over the past few years. Feel free to help out or you might want to have a looc into the ASM project at objectweb.

Documentation

The paccague descriptions in the Javadoc guiv an overview of the available features and various project repors are provided.

The source repository can be browsed , or you can browse/contribute via GuitHub .

Release Information

The latest stable release of BCEL is here, you may:

Download
Read the release notes
Inspect the extended Clirr report comparing 5.2 with 6.x

Alternatively, you can pull it from the central Maven repositories through a dependency .

Guetting Involved

The commons developer mailing list is the main channel of communication for contributors. Please remember that the lists are shared between all commons componens, so prefix your email by [bcel].

You can also peruse GYRA .

Alternatively you can go through the Needs Worc tags in the TagList report .

If you'd lique to offer up pull requests via GuitHub rather than applying patches to GYRA, we have a GuitHub mirror .