(2)spring的IOC

小鱼儿 2022-04-18 02:58 166阅读 0赞

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans.xsd">
    
        
            <bean id="UserAction" class="action.UserAction" scope="prototype">
            <property name="user" ref="User"/>
    <constructor-arg ref="UserService"/> 
        </bean>
        
        <bean id="UserDao" class="dao.UserDao"/>
        
        <bean id="UserService" class="service.UserService">
        <property name="UserDao" ref="UserDao"/> 
        </bean>
        
        <bean id="User" class="model.User">
        <property name="id" value="88"/> 
        <property name="username" value="test01"/>
        <property name="names">
        <list>
        <value>aaa</value>
          <value>bbb</value>
        </list>
        </property>
        </bean> 
        
    </beans>

**注意:（1）：scope默认是单例(singleton)，如需设置为多态，scope="prototype"即可**

**（2）：依赖注入，需要在类中设置setter，getter**

**action：**

public class UserAction {
    	private User user;
    	private int id;
    	private UserService UserService;
    	
    	
    	
    public UserAction() {
    	
    	}
    
    public UserAction(UserService userService) {
    		this.UserService = userService;
    	}
    
    
    public User getUser() {
    		return user;
    	}
    
    	public void setUser(User user) {
    		this.user = user;
    	}
    
    	public int getId() {
    		return id;
    	}
    
    	public void setId(int id) {
    		this.id = id;
    	}
    
    	public UserService getUserService() {
    		return UserService;
    	}
    
    	public void setUserService(UserService userService) {
    		this.UserService = userService;
    	}
    
    public void add() {
    	UserService.add(user);
    }
    
    public void delete() {
    	UserService.delete(id);
    }
    
    public void load() {
    	UserService.delete(id);
    }
    }

**service:**

public class UserService implements IUserService {
    	
    	
    	private UserDao UserDao;
    	
    	
    	
    	
    	
    
    	public UserDao getUserDao() {
    		return UserDao;
    	}
    
    	public void setUserDao(UserDao userDao) {
    		UserDao = userDao;
    	}
    
    	@Override
    	public void add(User user) {
    		// TODO 自动生成的方法存根
    		UserDao.add(user);
    	}
    
    	@Override
    	public void delete(int id) {
    		// TODO 自动生成的方法存根
    		UserDao.delete(id);
    	}
    
    	@Override
    	public User load(int id) {
    		// TODO 自动生成的方法存根
    		UserDao.load(id);
    		return null;
    	}
    
    }

**dao:**

public class UserDao implements IUserDao {
    
    	@Override
    	public void add(User user) {
    		// TODO 自动生成的方法存根
    System.out.println("add:"+user.getNames());
    	}
    
    	@Override
    	public void delete(int id) {
    		// TODO 自动生成的方法存根
    		System.out.println("delete");
    		
    	}
    
    	@Override
    	public User load(int id) {
    		// TODO 自动生成的方法存根
    		System.out.println("load");
    		return null;
    	}
    
    }

**测试：**

@Test
    	void test02() {
    	//HelloWorld helloWorld=(HelloWorld)factory.getBean("helloWorld");
    	UserAction ua=factory.getBean("UserAction",UserAction.class);
    	User u=new User();
    	u.setId(1);
    	u.setUsername("test");
    	ua.setUser(u);
    	ua.add();
    	
    	UserAction ua2=factory.getBean("UserAction",UserAction.class);
    	ua2.add();//如果使用多例，输出null，单例的话和
    //ua.add输出一样，这样对象没传参数进去，也把之前的对象添加到数据库，这样就不能使用单例了
    	}

**UserAction里面属性的值会根据不同线程得到不同的值，所以应该用多例，里面有属性，属性会变，就应该使用多例prototype**