java动态代理--代理接口无实现类

使用通过接口定义，或解析接口注解等完成相关功能，如mybatis的SqlSession.getMapper的实现

1. 接口定义

package cn.proxy;  

public interface IHello {  
    String say(String aa);  
}  

1. 代理实现

package cn.proxy;  
import java.lang.reflect.InvocationHandler;  
import java.lang.reflect.Method;  
import java.lang.reflect.Proxy;  
/** 
  JDK动态代理代理类  
 */  
@SuppressWarnings("unchecked")  
public class FacadeProxy implements InvocationHandler {    
    @Override    
    public Object invoke(Object proxy, Method method, Object[] args)    
            throws Throwable {    
        System.out.println("接口方法调用开始");    
        //执行方法    
        System.out.println("method toGenericString:"+method.toGenericString());  
        System.out.println("method name:"+method.getName());  
        System.out.println("method args:"+(String)args[0]);  
        System.out.println("接口方法调用结束");    
        return "调用返回值";    
    }    
    public static <T> T newMapperProxy(Class<T> mapperInterface) {  
        ClassLoader classLoader = mapperInterface.getClassLoader();  
        Class<?>[] interfaces = new Class[]{mapperInterface};  
        FacadeProxy proxy = new FacadeProxy();  
        return (T) Proxy.newProxyInstance(classLoader, interfaces, proxy);  
      }  
}  

1. 运行

package cn.proxy;  

public class Test {  
    public static void main(String[] args) {  
        IHello hello = FacadeProxy.newMapperProxy(IHello.class);  
        System.out.println(hello.say("hello world"));  
    }  
}  

1. 运行结果

接口方法调用开始  
method toGenericString:public abstract java.lang.String cn.proxy.IHello.say(java.lang.String)  
method name:say  
method args:hello world  
接口方法调用结束  
调用返回值 

转载于http://blog.csdn.net/zhu_tianwei/article/details/40076391