Определяем все классы, которые использует приложение на Java

    // The classes loaded by this class loader. The only purpose of this table
    // is to keep the classes from being GC'ed until the loader is GC'ed.
    private final Vector<Class<?>> classes = new Vector<>();

        // get access to the private variable ClassLoader.classes
        Field fld = ClassLoader.class.getDeclaredField("classes");
        fld.setAccessible(true);

        // list classes loaded by the application class loader		
        ClassLoader appLoader = MyApp.class.getClassLoader();
        Vector<Class<?>> classes = (Vector<Class<?>>) fld.get(appLoader);
        Map<String, Class<?>> map = new HashMap<String, Class<?>>();
        for (Class<?> cls : classes) {
            System.out.println(cls);
        }

    // classes groupped by jar
    Map<String, Collection<Class> > classesByJar = new HashMap<String, Collection<Class>>();
    for(Class clz : loadedClasses){
        String jarLocation = clz.getProtectionDomain().getCodeSource().getLocation().toString();
        Collection<Class>  jarClasses = classesByJar.get(jarLocation );
        if(jarClasses == null) {
            jarClasses = new ArrayList<Class>();
            classesByJar.put(jarLocation, jarClasses);
        }
        jarClasses.add(clz);
    }