class A {
    int x;
    public void method2() {...}
        class B {
            int number;
            public void methods() {...}
        }
    }

CompilationUnit cu = JavaParser.parse(in);

 ClassVisitor classVisitor = new ClassVisitor();
 classVisitor.visit(cu, null);

 class ClassVisitor extends VoidVisitorAdapter<Void> {
    @Override
    public void visit(ClassOrInterfaceDeclaration n, Void arg) {
        System.out.println(n.getFields());

        // get class methods
        for(MethodDeclaration method : n.getMethods()) {
            System.out.println("Name :" + method.getName());
            System.out.println("Body :" + method.getBody().get());
           }
        }
    }
}

CompilationUnit cu = JavaParser.parse(in);

for(TypeDeclaration<?> type : cu.getTypes()) {
    log.info("Type Name :{}", type.getName());
}

for(TypeDeclaration type : cu.getTypes()) {
        // first give all this java doc member
        List<BodyDeclaration> members = type.getMembers();
        // check all member content
        for(BodyDeclaration member : members) {
            // if member state equal ClassOrInterfaceDeclaration, and you can identify it which is inner class
            if(member.isClassOrInterfaceDeclaration()) {
                log.info("class name :{}", member.asClassOrInterfaceDeclaration().getName());
                // get inner class method
                for(MethodDeclaration method : member.asClassOrInterfaceDeclaration().getMethods()) {
                    log.info("Method Name :{}", method.getName());
                }
                VerifyInnerClassAndParse(member.asClassOrInterfaceDeclaration());
            }
        }
    }