How can I invoke a method when the method name is in the form of a given string

Question

Without knowing the class of obj, how can I call the method identified by methodName on it?​

Object obj;
String mName = "gName";

Answer 1

I tried doing it this way -

java.lang.reflect.Method methods;
try {
  methods = obj.getClass().getMethod(methodName, parameter1.class, parameter2.class, ..);
} catch (SecurityException e) { ... }
  catch (NoSuchMethodException e) { ... }

The parameters identify the very specific method you need.

Then you invoke that method by calling:

try {
  method.invoke(obj, arg1, arg2,...);
} catch (IllegalArgumentException e) { ... }
  catch (IllegalAccessException e) { ... }
  catch (InvocationTargetException e) { ... }

Answer 2

You could probably use method invocation from reflection:

Class<?> 
c = Class.forName("class name");
Method method = c.getDeclaredMethod("method name", parameterTypes);
method.invoke(objectToInvokeOn, params);

Where:

· class name - name of the class

· objectToInvokeOn - is of type Object and is the object you want to invoke the method on

· method name -  name of the method you want to call

· parameterTypes  - is of type Class[] and declares the parameters the method takes

· params - is of type Object[] and declares the parameters to be passed to the method.