动态代理 测试代码

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

public class FactoryDao {
 @SuppressWarnings("unchecked")
 public static UserDao getUserDaoImpl(UserDao dao) throws Exception {
  Class proxyClass = Proxy.getProxyClass(dao.getClass().getClassLoader(),
    dao.getClass().getInterfaces());
  
  Constructor constructor = proxyClass
    .getConstructor(InvocationHandler.class);
  
  UserDao userdaoProxy = (UserDao) constructor
    .newInstance(new InvocationHandler() {
     
     public Object invoke(Object proxy, Method method,
       Object[] args) throws Throwable {
      if ("delete".equals(method.getName())) {
       System.out.println("您调用了delete方法：权限验证完毕");
      }
      UserDaoImpl dao = new UserDaoImpl();
      return method.invoke(dao, args);
     }

    });
  return userdaoProxy;
 }
}