import java.lang.reflect.*;

interface TestIF {

String hello(String name);

}

class TestImpl implements TestIF {

public String hello(String name) {

return String.format("Hello %s, this is %s", name, this);

}

}

class TestInvocationHandler implements InvocationHandler {

private Object testImpl;

public TestInvocationHandler(Object impl) {

this.testImpl = impl;

}

@Override

public Object invoke(Object proxy, Method method, Object[] args)

throws Throwable {

if(Object.class == method.getDeclaringClass()) {

String name = method.getName();

if("equals".equals(name)) {

return proxy == args[0];

} else if("hashCode".equals(name)) {

return System.identityHashCode(proxy);

} else if("toString".equals(name)) {

return proxy.getClass().getName() + "@" +

Integer.toHexString(System.identityHashCode(proxy)) +

", with InvocationHandler " + this;

} else {

throw new IllegalStateException(String.valueOf(method));

}

}

return method.invoke(testImpl, args);

}

}

public class ProxyExample {

public static void main(String... args) {

TestIF t = (TestIF) Proxy.newProxyInstance(TestIF.class.getClassLoader(),

new Class<?>[] {TestIF.class},

new TestInvocationHandler(new TestImpl()));

System.out.printf("t.hello(Duke): %s%n", t.hello("Duke"));

System.out.printf("t.toString(): %s%n", t);

System.out.printf("t.hashCode(): %H%n", t);

System.out.printf("t.equals(t): %B%n", t.equals(t));

System.out.printf("t.equals(new Object()): %B%n", t.equals(new Object()));

System.out.printf("t.equals(null): %B%n", t.equals(null));

}

}