Fully qualified name of a class?

class MethodFinder {

    public static String findMethod(String methodName, String[] classNames) {
            for(String cn: classNames){
                if(cn.getMethods() == methodName){
                    return methodName.getName();
                }
            }
    }
}

The method should return fully qualified name of a class.How to fix it? For example, the method name is abs and possible classes are String, StringBuffer and Math.

String and StringBuffer have no method with the name abs. So they are not the class we are looking for. Math class has a method with the name abs. The method should return the fully-qualified name of Math class, java.lang.Math in this case.