spring基础-控制反转和依赖注入

新建maven项目

导入依赖

<dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.3.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.2</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

UserDao.java

package com.shrimpking.dao;

/**
 * Created by IntelliJ IDEA.
 *
 * @Author : Shrimpking
 * @create 2023/7/3 21:47
 */
public interface UserDao
{
    public void login();
}

UserDaoImpl.java

package com.shrimpking.dao;

/**
 * Created by IntelliJ IDEA.
 *
 * @Author : Shrimpking
 * @create 2023/7/3 21:48
 */
public class UserDaoImpl implements UserDao
{
    @Override
    public void login()
    {
        System.out.println("UserDao login");
    }
}

 UserDaoTest.java

package com.shrimpking.t1;

import com.shrimpking.dao.UserDao;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * Created by IntelliJ IDEA.
 *
 * @Author : Shrimpking
 * @create 2023/7/3 21:52
 */
public class UserDaoTest
{
    @Test
    public void test()
    {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserDao userDao = context.getBean("userDao", UserDao.class);
        userDao.login();
    }
}

 applicationContext.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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="userDao" class="com.shrimpking.dao.UserDaoImpl"/>

    <bean id="userService" class="com.shrimpking.service.UserServiceImpl">
        <property name="userDao" ref="userDao"/>
    </bean>
</beans>

UserService.java

package com.shrimpking.service;

/**
 * Created by IntelliJ IDEA.
 *
 * @Author : Shrimpking
 * @create 2023/7/3 21:57
 */
public interface UserService
{
    public void login();
}

UserServiceImpl.java

package com.shrimpking.service;

import com.shrimpking.dao.UserDao;
import com.shrimpking.dao.UserDaoImpl;

/**
 * Created by IntelliJ IDEA.
 *
 * @Author : Shrimpking
 * @create 2023/7/3 21:57
 */
public class UserServiceImpl implements UserService
{

    private UserDao userDao;

    public void setUserDao(UserDao userDao)
    {
        this.userDao = userDao;
    }

    @Override
    public void login()
    {
        this.userDao.login();
        System.out.println("UserService login");
    }
}

UserServiceTest.java

package com.shrimpking.t1;

import com.shrimpking.service.UserService;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * Created by IntelliJ IDEA.
 *
 * @Author : Shrimpking
 * @create 2023/7/3 22:03
 */
public class UserServiceTest
{
    @Test
    public void test()
    {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserService userService = context.getBean("userService", UserService.class);
        userService.login();
    }
}