动态代理

public interface IHello {

	public void say(String name);
	
	public void play(String sth);
}

public class HelloImp implements IHello{

	@Override
	public void say(String name) {
		System.out.println("Hello: "+name);
	}

	@Override
	public void play(String sth) {
		System.out.println("Play: "+sth);
	}

}


import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;


public class LogHandler implements InvocationHandler {

	private Object bindObj;
	
	@Override
	public Object invoke(Object proxy, Method method, Object[] args)
			throws Throwable {
		System.out.println("before....");
		Object result = method.invoke(bindObj, args); 
		System.out.println("after....");
		return result;
	}

	public Object bind(Object bindObj){  
        this.bindObj = bindObj;  
        return Proxy.newProxyInstance(bindObj.getClass().getClassLoader(), bindObj.getClass().getInterfaces(), this);  
    }  
	
}

public class ProxyDemo {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		LogHandler logHandler = new LogHandler();  
        
        IHello hello = (IHello)logHandler.bind(new HelloImp());  
          
        hello.say("callan");  
        
        hello.play("football");
	}

}