Spring再接触 Annotation part1

使用annotation首先得加这两条代码

beans.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
           http://www.springframework.org/schema/context
           http://www.springframework.org/schema/context/spring-context-2.5.xsd">
    <context:annotation-config />                          //相当于初始化了四个bean 确保能够识别出annotation
  <bean id="u" class="com.bjsxt.dao.impl.UserDAOImpl">
  </bean>
  <bean id="u2" class="com.bjsxt.dao.impl.UserDAOImpl">
  </bean>
    
  <bean id="userService" class="com.bjsxt.service.UserService" >
      
  </bean>
  

</beans>

Userservice

package com.bjsxt.service;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;

import com.bjsxt.dao.UserDAO;
import com.bjsxt.model.User;



public class UserService {
    
    private UserDAO userDAO;  
    
    public void init() {
        System.out.println("init");
    }
    
    public void add(User user) {
        userDAO.save(user);
    }
    public UserDAO getUserDAO() {
        return userDAO;
    }
    
    @Autowired                                                                                //使用anotation
    public void setUserDAO(@Qualifier("u") UserDAO userDAO) {                               //制定具体注入哪一个
        this.userDAO = userDAO;
    }
    

    
    public void destroy() {
        System.out.println("destroy");
    }
}