//Loader.java
//
// A simple program to demonstrate dynamic loading and usage of a class.



import java.lang.reflect.*;
// Contains the Method class.

public class Loader
{
    public static void main(String [] args) throws ClassNotFoundException,
						   InstantiationException,
						   IllegalAccessException,
						   NoSuchMethodException,
						   InvocationTargetException
    {
	String strClassName = "Talker";
	// Name of the class to be loaded.
	String strMethodName = "say";
	// Name of the method to be executed in the loaded class.
	Class [] parameterTypes = new Class[0];
	// List of parameter types for the aformentioned method.  In this case,
	// there are none.
	String [] arguments = new String[0];
	// Actual values of the aformentioned arguments.
	Method methodBuff;
	// A method buffer used to deal with a method in the loaded class.
	Object returnValue;
	// An untyped return value; must be type-cast to be used.
	Object anInstance;
	// An untyped instance variable for the class to be loaded.
	Class classBuff;
	// A buffer for the class to be loaded.


	classBuff = Class.forName( strClassName );
	//  loads the class named by the given string.

	anInstance = classBuff.newInstance();
	//  creates an instance of the previously loaded class.

       	methodBuff = classBuff.getMethod( strMethodName, parameterTypes );
	//  returns a method of given name and array of parameter types from the loaded class
	//  for use.

       	returnValue = methodBuff.invoke( anInstance, arguments );
	//  A shell for the method to invoke itself.  'arguments' is an array of values for
	//  the arguments.
    }
}