How do I invoke a Java method when given the method name as a string?

Question

If I have two variables:

Object obj;
String methodName = \"getName\";

Without knowing the class of obj, how can I call the met

Answer 1

This is working fine for me :

public class MethodInvokerClass {
    public static void main(String[] args) throws NoSuchMethodException, SecurityException, IllegalAccessException, IllegalArgumentException, ClassNotFoundException, InvocationTargetException, InstantiationException {
        Class c = Class.forName(MethodInvokerClass.class.getName());
        Object o = c.newInstance();
        Class[] paramTypes = new Class[1];
        paramTypes[0]=String.class;
        String methodName = "countWord";
         Method m = c.getDeclaredMethod(methodName, paramTypes);
         m.invoke(o, "testparam");
}
public void countWord(String input){
    System.out.println("My input "+input);
}

}

Output:

My input testparam

I am able to invoke the method by passing its name to another method (like main).