java 代理模式（静态代理+动态代理）

静态代理：

ISubject：

/**
 * @author com.tiantian
 * @version 创建时间：2012-11-20 下午1:49:29
 */
public interface ISubject {
    public void request();
}

RealSubject（真实角色）：

/**
 * @author com.tiantian
 * @version 创建时间：2012-11-20 下午1:51:37
 */
public class RealSubject implements ISubject{

    @Override
    public void request() {
        System.out.println("realSubject requesting");
    }
}

ProxySubject（代理类）：

/**
 * @author com.tiantian
 * @version 创建时间：2012-11-20 下午1:52:22
 */
public class ProxySubject implements ISubject{
    private RealSubject realSubject;
    public ProxySubject() {
        realSubject = new RealSubject();
    }

    @Override
    public void request() {
        System.out.println("do something before");
        realSubject.request();
        System.out.println("do something after");
    }
}

Test（客户端测试）:

/**
 * @author com.tiantian
 * @version 创建时间：2012-11-20 下午1:54:47
 */
public class Test {
    public static void main(String[] args) {
        ISubject proxySubject = new ProxySubject();
        proxySubject.request();
    }
}

------------------------------------------------------------------------------------------------------------------------------

动态代理：

ISubject：

/**
 * @author com.tiantian
 * @version 创建时间：2012-11-20 下午2:51:31
 */
public interface ISubject {
    public void request();
}

RealSubject：

/**
 * @author com.tiantian
 * @version 创建时间：2012-11-20 下午2:52:00
 */
public class RealSubject implements ISubject{

    @Override
    public void request() {
        System.out.println("realSubject requesting");
    }
}

SubjectInvocationHandler（调用处理类）：

/**
 * @author com.tiantian
 * @version 创建时间：2012-11-20 下午2:54:38
 * 调用处理类
 */
public class SubjectInvocationHandler implements InvocationHandler{
    private Object obj;
    
    public SubjectInvocationHandler(Object obj) {
        this.obj = obj;
    }
    
    /**
     * 生成代理类工厂
     * @author com.tiantian
     * @param realObj
     * @return 返回生成的代理类
     */
    public static Object getProxyInstanceFactory(Object realObj){
        Class<?> classType = realObj.getClass();
        return Proxy.newProxyInstance(classType.getClassLoader(), 
                classType.getInterfaces(), new SubjectInvocationHandler(realObj));
    }
    
    @Override
    public Object invoke(Object proxy, Method method, Object[] args)
            throws Throwable {
        System.out.println("before");
        
        method.invoke(obj, args);
        
        System.out.println("after");
        
        return null;
    }
}

Test：

/**
 * @author com.tiantian
 * @version 创建时间：2012-11-20 下午2:56:25
 */
public class Test {
    public static void main(String[] args) {
        RealSubject realSubject = new RealSubject();
//        InvocationHandler handler = new SubjectInvocationHandler(realSubject);
//        ISubject subject = (ISubject)Proxy.newProxyInstance(realSubject.getClass().getClassLoader(),
//                realSubject.getClass().getInterfaces(), handler);
        ISubject subject = (ISubject)SubjectInvocationHandler.getProxyInstanceFactory(realSubject);
        subject.request();
        
    }
}