Java静态代理的实现

静态代理,不使用其他Java类
做到动态的调用接口的不同实现
静态代理,优点:不需要其他的类,实现简单 缺点:需要更改源代码
实现
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 UserDaoProxyImpl implements UserDao {
 
 public UserDaoProxyImpl(UserDao dao) {
  super();
public static void main(String[] args) {
  UserDao dao1 = new UserDaoMySqlImpl();
  UserDao dao2 = new UserDaoOracleImpl();
  UserDao dao3 = new UserDaoProxyImpl(dao2);
  
  dao3.addUser();
 }
   this.dao = dao;
 }

 private UserDao dao = null;

 @Override
 public void addUser() {
  dao.addUser();
 }

 @Override
 public void deleteUser() {
  dao.deleteUser();
 }

}

 测试类:
 

public static void main(String[] args) {
		UserDao dao1 = new UserDaoMySqlImpl();
		UserDao dao2 = new UserDaoOracleImpl();
		UserDao dao3 = new UserDaoProxyImpl(dao2);
		
		dao3.addUser();
	}