This program demonstrates the use of proxies and reflection : Proxy « Reflection « Java

This program demonstrates the use of proxies and reflection

   This program is a part of the companion code for Core Java 8th ed.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <>.

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Arrays;
import java.util.Random;

 * This program demonstrates the use of proxies.
 * @version 1.00 2000-04-13
 * @author Cay Horstmann
public class ProxyTest
   public static void main(String[] args)
      Object[] elements = new Object[1000];

      // fill elements with proxies for the integers 1 ... 1000
      for (int i = 0; i < elements.length; i++)
         Integer value = i + 1;
         InvocationHandler handler = new TraceHandler(value);
         Object proxy = Proxy.newProxyInstance(null, new Class[] { Comparable.class } , handler);
         elements[i] = proxy;

      // construct a random integer
      Integer key = new Random().nextInt(elements.length) + 1;

      // search for the key
      int result = Arrays.binarySearch(elements, key);

      // print match if found
      if (result >= 0) System.out.println(elements[result]);

 * An invocation handler that prints out the method name and parameters, then
 * invokes the original method
class TraceHandler implements InvocationHandler
    * Constructs a TraceHandler
    * @param t the implicit parameter of the method call
   public TraceHandler(Object t)
      target = t;

   public Object invoke(Object proxy, Method m, Object[] args) throws Throwable
      // print implicit argument
      // print method name
      System.out.print("." + m.getName() + "(");
      // print explicit arguments
      if (args != null)
         for (int i = 0; i < args.length; i++)
            if (i < args.length - 1) System.out.print(", ");

      // invoke actual method
      return m.invoke(target, args);

   private Object target;


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1.A demonstration of a proxy factory
2.Demonstrates the basic concept of proxies generated by clients to the proxies
3.Demonstrates a dangerous use of proxy names
4.Creating a Proxy Object
5.A dynamic proxy adapter which allows overriding several methods of a target proxy
6.A high-performance factory for dynamic proxy objects