java 动态代理

        java实现动态代理 有jdk 或者cglib，使用jdk的必须实现接口

 

     代理模式实现一

 

      

public interface  Log{
	
	public  void beforelog();
	
	public void aftelog();

}

 

public class LogImpl implements Log{

	@Override
	public void beforelog() {
	 System.out.println("befor");

	}

	@Override
	public void afterlog() {
		 System.out.println("after");

	}

}

 

public class LogProxy implements Log {

	
	public  Log delegate;
	
	public LogProxy (Log delegate){
		this.delegate = delegate;
		
	}
	
	@Override
	public void beforelog() {
		    System.out.println("begin ");
		delegate.beforelog();
		 System.out.println("end  ");
	}

	@Override
	public void afeterlog() {
		System.out.println("begin ");
		delegate.afterlog();
		System.out.println("end  ");

	}

}

 

public class TestProxy {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Log log= new LogProxy(new LogImpl());
		
		 log.beforelog();
		
		log.afterlog();

	}

}

  

二 jdk 动态代理

  

public class ProxyFactory implements InvocationHandler {

	private Object delegate;
	
	public Object bind(Object delegate){
		
		 this.delegate = delegate;
		 
				 
		 return Proxy.newProxyInstance(delegate.getClass().getClassLoader(), delegate.getClass().getInterfaces(),this);
	}
	
	@Override
	public Object invoke(Object proxy, Method method, Object[] args)
			throws Throwable {
		Object result = null;
		
		 result = method.invoke(delegate, args);
		return result;
	}

}

 

public class TestJDKProxy {
	
	 public static void main(String[] args) {
		
		 Log log= (Log) new ProxyFactory().bind(new LogImpl());
		 log.beforlog();
		 
		 log.afterlog();
	}

}

   

 三 cglib 代理

   

public class CglibProxyFactory implements MethodInterceptor {
    
	
	
	private Object delegate;
	
	public Object bind(Object delegate){
		this.delegate = delegate;
		
		Enhancer  hancer = new Enhancer();
		
		
		hancer.setSuperclass(delegate.getClass());
		
		hancer.setCallback(this);
		
				return hancer.create();
		
	}
	
	@Override
	public Object intercept(Object arg0, Method arg1, Object[] arg2,
			MethodProxy arg3) throws Throwable {
		
		 Object o = arg3.invoke(this.delegate, arg2);
		
		return  o;
	}

}

 

public class TestCglibProxy {
	
	 public static void main(String[] args) {
		
		DefaulLog log= (DefaulLog) new CglibProxyFactory().bind(new DefaulOffer());
		
		log.beforlog();
		
		log.afterlog();
	}

}