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

using import java.lang.reflect.*;

public static Object launchProcess(String className, String methodName, Class[] argsTypes, Object[] methodArgs)
        throws Exception {

    Class processClass = Class.forName(className); // convert string classname to class
    Object process = processClass.newInstance(); // invoke empty constructor

    Method aMethod = process.getClass().getMethod(methodName,argsTypes);
    Object res = aMethod.invoke(process, methodArgs); // pass arg
    return(res);
}

and here is how you use it:

String className = "com.example.helloworld";
String methodName = "print";
Class[] argsTypes = {String.class,  String.class};
Object[] methArgs = { "hello", "world" };   
launchProcess(className, methodName, argsTypes, methArgs);