Java动态代理的实现

动态代理,代理类需要实现接口java.lang.reflect.InvocationHandler
接口UserDao

public interface UserDao {
	void addUser();
	void deleteUser();
}

 两个普通的实现

public class UserDaoOracleImpl implements UserDao {

 @Override
 public void addUser() {
  System.out.println("UserDaoOracleImpl.addUser()");
 }

 @Override
 public void deleteUser() {
  System.out.println("UserDaoOracleImpl.deleteUser()");
 }

}

public class UserDaoMySqlImpl implements UserDao {

 @Override
 public void addUser() {
  System.out.println("UserDaoMySqlImpl.addUser()");
 }

 @Override
 public void deleteUser() {
  System.out.println("UserDaoMySqlImpl.deleteUser()");

 }

}

 
代理的接口实现

public class UserDaoDynamicProxy implements InvocationHandler {
 
 private Object target;

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

}

 测试类

public class TestDynamicProxy {

 public static void main(String[] args) {
  
  UserDaoDynamicProxy udp = new UserDaoDynamicProxy();
  
  UserDao dao = (UserDao) udp.getProxyInstance(new UserDaoOracleImpl());
  
  dao.addUser();
 
 }

}