Tool to Delambdafy Java code from Java 8 to Java 7 syntax? [closed]

Question

Does anyone know of any tool to convert Java 8 code (at the source level) that uses lambdas and method references into Java 7 code that uses anonymous inner classes? I know about Retrolambda, but that works at the bytecode level, not the source level.

For now, I have a version working that works as an IntelliJ plugin. I extended the current IntelliJ code to convert all lambdas in a package at one go, instead of selecting each lambda individually and converting to anonymous inner class. The problem with this approach though is that it cannot work as a standalone tool, say a maven plugin as it needs an IntelliJ context to work.

Edit: Note that the focus is on converting lamda/method references to anonymous inner classes. I am not concerned about API changes in Java 8 which would be caught by a Java 7 compiler and reported as compilation errors.

Answer 1

In IntelliJ Idea open 'Project Structure' and then set Project language level to 7.0. Analyze your code again if that is needed. That will help in most of the cases but prefer to do it class by class (file by file) basis.