Spring IoC实现解耦合

 1 public class UserDaoImpl implements UserDao{
 4     @Override
 5     public void save(User user) {
 6         // TODO Auto-generated method stub
 7         System.out.println("保存用户信息到数据库");

 1 public class UserServiceImpl implements UserService{
 2     private UserDao userDao;
 3 
 4     public UserDao getUserDao() {
 5         return userDao;
 6     }
 7     //后面要调用该方法
 8     public void setUserDao(UserDao userDao) {
 9         this.userDao = userDao;
10     }
11     @Override
12     public void addUser(User user) {
13         // TODO Auto-generated method stub
14         userDao.save(user);
15     }
16 }

测试类获取Bean的实例，调用功能方法

 1 @Test
 2     public void test() {
 3         ApplicationContext context = new ClassPathXmlApplicationContext
                         ("applicationContext.xml");
 4         UserServiceImpl service =  (UserServiceImpl)context.getBean("userServiceImpl");//此处是xml中id
 5         User user = (User) context.getBean("user");
 6         user.setUsername("admin");
 7         user.setPassword("123");
 8         
 9         service.addUser(user);
10     }

xml文件配置文件，给Service对应的Bean注入Dao对象

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4     xsi:schemaLocation="http://www.springframework.org/schema/beans
 5     http://www.springframework.org/schema/beans/spring-beans-3.1.xsd ">
 6     
 7     <!-- 定义userDaoImpl对象,并指定id为userDaoImpl -->
 8     <bean id="userDaoImpl" class="cn.bdqn.biz.dao.impl.UserDaoImpl" />
 9     <!-- 定义User对象,并指定id为user -->
10     <bean id="user" class="cn.bdqn.biz.pojo.User" />
11     
12     <!-- 定义UserServiceImpl对象,并指定id为userServiceImpl -->
13     <bean id="userServiceImpl" class="cn.bdqn.biz.service.impl.UserServiceImpl">
14         <!--为userServiceImpl的userDao属性赋值,需要注意的是,这里要调用setUserDao()方法 -->
15         <property name="userDao">
16             <!-- 引用id为userDao的对象为userServiceImpl的userDao属性赋值 -->
17             <ref bean="userDaoImpl" />
18         </property>
19     </bean>
20     
21 </beans>