JavaCC is an old and venerable tool, used in so many projects. In recent years however ANTLR seems to have a growing community and there are different tools to support ANTLR. Also, ANTLR can be generate a parser for so many target languages that are not supported by JavaCC.
So I hacked together this little project, in Kotlin.
For now it basically get a JavaCC grammar and produces a lexer and a parser ANTLR grammar which should hopefully be equivalent.
Simply look at the class JavaCCToAntlrConverter. It takes the file name of the JavaCC grammar and outputs
a Lexer and a parser Grammar.
val file = File("src/test/resources/java.jj")
val grammarName = file.nameWithoutExtension.capitalize()
val javaCCGrammar = loadJavaCCGrammar(file)
val antlrGrammar = javaCCGrammar.convertToAntlr(grammarName)
this.genericParser = antlrGrammar.genericParser()
val ast = genericParser.parse("class A { }")