@Component 注解

@Component
　　a) 初始化的名字默认为类名首字母小写：UserService 在容器中默认为 userService
　　b) 可以指定初始化 bean 的名字: @Component(value="userService") 

xml 配置

<?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 />
  
  <context:component-scan base-package="com.bjsxt" /><!-- 指定包 -->
  
</beans>

bean 配置：

　　UserDAOImpl

package com.bjsxt.dao.impl;

import org.springframework.stereotype.Component;

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

@Component    //默认名字：userDAOImpl
public class UserDAOImpl implements UserDAO{

    public void save(User u) {
        System.out.println("a user saved!");
    }

}

　　UserService

package com.bjsxt.service;

import javax.annotation.Resource;

import org.springframework.stereotype.Component;

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

@Component(value="userService")
public class UserService {
    
    private UserDAO userDAO;
    
    public void init(){
        System.out.println("init");
    }
    
    public UserService(){}
    
    public UserService(UserDAO userDAO){
        super();
        this.userDAO = userDAO;
    }
    
    public void addUser(User u){
        this.userDAO.save(u);
    }

    public UserDAO getUserDAO() {
        return userDAO;
    }

    @Resource(name="userDAOImpl")
    public void setUserDAO(UserDAO userDAO) {
        this.userDAO = userDAO;
    }
    
    public void destroy(){
        System.out.println("destroy");
    }
    
}

代码链接: http://pan.baidu.com/s/1i4GwEPn 密码: awdu

jar包链接: http://pan.baidu.com/s/1hs655SK 密码: 6h8x