Java Compiler Compiler (JavaCC) is (according to sun) "the most popular parser generator" for use with Java [tm] applications. . A parser generator is a tool that reads a grammar specification and converts it to a Java program that can recognize matches to the grammar. In addition to the parser generator itself, JavaCC provides other standard capabilities related to parser generation such as tree building (via a tool called JJTree included with JavaCC), actions, debugging, etc.
