Supported 1.5 Language Features

• generics
• extended for loops
• static imports
• autoboxing/unboxing
• varargs

Unsupported 1.5 Language Features

• enumerations
• annotations

Limitations

Because Retroweaver operates on class files which are already compiled by a 1.5 compiler, it is possible that your source code has made references to classes or methods which are only available in the 1.5 runtime. If this is the case, your code will fail with ClassNotFoundExceptions/NoClassDefFoundErrors at runtime, when run on a 1.4 virtual machine. An intended future enhancement for Retroweaver, is to automatically detect those situations and issue warnings as it transforms class files.

Usage

1. Compile your source code using a 1.5 compiler.
2. Run com.rc.retroweaver.Weaver against your classes folder. For example, running:

   java -cp retroweaver.jar;lib\bcel-5.1.jar;lib\jace.jar;lib\Regex.jar com.rc.retroweaver.Weaver classes

   will transform all of the class files in the classes folder from version 1.5 to version 1.4.
3. When deploying your application, include retroweaver.jar. It contains classes that are needed to support certain 1.5 language features during runtime. (i.e. autoboxing, class literals, etc...).