Using Java Compiler API, what classes were created?

Question

Because a single Java file can compile into any number of class files, is there some way from the compiler API to find out which class files were generated? It's outputting to a directory that may have other files in it, so I can't just look at that.

Answer 1

I figured out something that appears to work. The *FileManager has callbacks to get the locations for things, including things for output. You can wrap it using the ForwardingJavaFileManager, override, and store the values from the calls.

final List<String> classFiles = new ArrayList<>();
StandardJavaFileManager inner = compiler.getStandardFileManager(null, null, null);
JavaFileManager fileManager = new ForwardingJavaFileManager(inner) {
    @Override
    public JavaFileObject getJavaFileForOutput(Location location, String className,
                JavaFileObject.Kind kind, FileObject sibling) throws IOException {
        JavaFileObject o = super.getJavaFileForOutput(location, className, kind, sibling);
        classFiles.add(o.getName());
        return o;
    }
};