一、业务代码

1.1.、pom

<dependencies><!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.26</version></dependency><!-- https://mvnrepository.com/artifact/com.mchange/c3p0 --><!--<dependency><groupId>com.mchange</groupId><artifactId>c3p0</artifactId><version>0.9.5.2</version></dependency>--><!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc --><dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>5.3.27</version></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.11</version></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>2.1.0</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-beans</artifactId><version>5.2.5.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>5.2.5.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-core</artifactId><version>5.2.5.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-expression</artifactId><version>5.2.5.RELEASE</version></dependency><dependency><groupId>commons-logging</groupId><artifactId>commons-logging</artifactId><version>1.1.1</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.2.16</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.13.2</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>1.2.76</version></dependency><!-- 普通maven项目中使用Sl4j注解 --><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.22</version></dependency><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-api</artifactId><version>1.7.32</version></dependency><dependency><groupId>ch.qos.logback</groupId><artifactId>logback-classic</artifactId><version>1.2.10</version></dependency></dependencies>

1.2、UserDO

package org.star.entity.model;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;import java.io.Serializable;/*** @Author:* @Date: 2023/8/28 16:51* @Description:*/
@Data
@AllArgsConstructor
@NoArgsConstructor
public class UserDO implements Serializable {/*** 编号*/private Long id;/*** 用户名*/private String username;/*** 密码*/private String password;/*** 手机号码*/private String mobile;}

1.3、UserMapper

package org.star.mapper;import org.star.entity.model.UserDO;import java.util.List;/*** @Author:* @Date: 2023/8/28 16:53* @Description:*/
public interface UserMapper {/*** 查询所有用户信息* @return*/List<UserDO> listAllUser();}

1.4、UserMapper.xml

<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="org.star.mapper.UserMapper"><select id="listAllUser" resultType="org.star.entity.model.UserDO">select id,username,password,mobile from user</select></mapper>

1.5、UserService

package org.star.service;import org.star.entity.model.UserDO;import java.util.List;/*** @Author: liuhaibo* @Date: 2023/8/28 17:41* @Description:*/
public interface UserService {/*** 查询所有用户信息* @return*/List<UserDO> listAllUser();}

1.6、UserServiceImpl

package org.star.service.impl;import org.springframework.stereotype.Service;
import org.star.entity.model.UserDO;
import org.star.mapper.UserMapper;
import org.star.service.UserService;import javax.annotation.Resource;
import java.util.List;/*** @Author: liuhaibo* @Date: 2023/8/28 17:41* @Description:*/
@Service
public class UserServiceImpl implements UserService {@Resourceprivate UserMapper userMapper;@Overridepublic List<UserDO> listAllUser() {return userMapper.listAllUser();}
}

二、配置信息

2.1、jdbc.properties

db.driverClass=com.mysql.cj.jdbc.Driver
db.url=jdbc:mysql://localhost:3306/20230828_spring5?useSSL=false&useUnicode=true&characterEncoding=UTF8&serverTimezone=GMT
db.username=root
db.password=123456

2.2、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"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd"><!--组件扫描--><context:component-scan base-package="org.star"></context:component-scan><context:property-placeholder location="jdbc.properties"></context:property-placeholder><bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"><property name="driverClassName" value="${db.driverClass}"></property><property name="url" value="${db.url}"></property><property name="username" value="${db.username}"></property><property name="password" value="${db.password}"></property></bean><!--配置sqlSessionFactory，注入相关属性--><bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"><property name="dataSource" ref="dataSource"></property><property name="typeAliasesPackage" value="org.star.entity.model"></property><property name="mapperLocations" value="classpath:mapper/*.xml"></property><property name="configuration"><bean class="org.apache.ibatis.session.Configuration"><property name="logImpl" value="org.apache.ibatis.logging.stdout.StdOutImpl"></property></bean></property></bean><!--配置mapper的位置，并指定sqlSessionFactorysqlSession = sqlSessionFactory.openSession();mapper = sqlSession.getMapper();--><bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"><property name="basePackage" value="org.star.mapper"></property><property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property></bean></beans>

三、测试

3.1、AppTest

package org.star;import org.junit.Before;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.star.entity.model.UserDO;
import org.star.mapper.UserMapper;
import org.star.service.UserService;
import org.star.service.impl.UserServiceImpl;import java.util.List;/*** Unit test for simple App.*/
public class AppTest {private ClassPathXmlApplicationContext context = null;@Beforepublic void initApplicationContext() {context = new ClassPathXmlApplicationContext("applicationContext.xml");}@Testpublic void listAllUserTest() {userMapperTest();// userServiceTest();}private void userServiceTest() {UserService userService = context.getBean(UserServiceImpl.class);List<UserDO> userDOS = userService.listAllUser();System.out.println("userService userDOS = " + userDOS);}private void userMapperTest() {UserMapper userMapper = context.getBean(UserMapper.class);List<UserDO> userDOS = userMapper.listAllUser();System.out.println("userMapper userDOS = " + userDOS);}}