详解Spring如何整合Mybatis

2024-04-02 19:55

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第一步

导入相关jar包


<dependencies>
    <!--连接mysql-->
    <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.21</version>
    </dependency>
 
    <!--加载mybatis-->
    <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.4.6</version>
    </dependency>
 
    <!--junit测试-->
    <!-- https://mvnrepository.com/artifact/junit/junit -->
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.13.2</version>
        <scope>test</scope>
    </dependency>
 
    <!--spring-webmvc-->
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.3.8</version>
    </dependency>
 
    <!--spring-jdbc spring连接数据库必备包-->
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>5.3.8</version>
    </dependency>
 
    <!-- aspectjweaver - 在spring中使用动态代理-->
    <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver-->
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjweaver</artifactId>
        <version>1.9.6</version>
    </dependency>
 
    <!--mybatis与spring整合的包-->
    <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>2.0.6</version>
    </dependency>
 
    <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.20</version>
        <scope>provided</scope>
    </dependency>
 
</dependencies>
<!--下边配置：不管放在哪里的资源文件都会被编译-->
<build>
    <resources>
        <resource>
            <directory>class="lazy" data-src/main/resources</directory>
            <includes>
                <include>***.xml</include>
            </includes>
            <filtering>true</filtering>
        </resource>
        <resource>
            <directory>class="lazy" data-src/main/java</directory>
            <includes>
                <include>***.xml</include>
            </includes>
            <filtering>true</filtering>
        </resource>
    </resources>
</build>

第二步

编写配置文件

resources下：
spring-config.xml，此配置文件下，连接数据库，创建SqlSessionFactory


<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/aop
        https://www.springframework.org/schema/aop/spring-aop.xsd">
    <!--第一步：安装依赖包-->
    <!--
        第二步：
        安装完依赖，使用Spring来管理数据源：
        DriverManagerDataSource
        使用Spring的数据源替换Mybatis的配置，这里我们使用Spring提供的JDBC
    -->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.cj.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://127.0.0.1:3306/java_pro?serverTimezone=Asia/Shanghai&amp;useUnicode=true&amp;characterEncoding=utf8&amp;useSSL=false" />
        <property name="username" value="root" />
        <property name="password" value="lvxingchen" />
    </bean>
    <!--创建sqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--注入数据源，dataSource 就是上边我们配置的id="dataSource" -->
        <property name="dataSource" ref="dataSource" />
        <!--绑定mybatis配置文件-->
        <property name="configLocation" value="classpath:mybatis-config.xml" />
        <property name="mapperLocations" value="classpath:com/lxc/dao/UserMapper.xml" />
    </bean>
    <!--创建sqlSession，SqlSessionTemplate 就是我们使用的sqlSession-->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <!--只能通过构造器注入sqlSessionFactory，因为没有set方法-->
        <constructor-arg index="0" ref="sqlSessionFactory" />
    </bean>
 
    <!-- 把接口实现类 UserMapperImp 注入到spring中-->
    <bean id="userMapper" class="com.lxc.dao.UserMapperImp">
        <property name="sqlSessionTemplate" ref="sqlSession"/>
    </bean>
</beans>

mybatis-config.xml，下边 mybatis 的配置在上边 spring-config.xml 也可以，但是为了更加清晰，职责明确，把别名配置放在了mybatis-config.xml 中配置了。


<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<!--configuration配置-->
<configuration>
    <!--别名配置-->
    <typeAliases>
        <package name="com.lxc.domain" />
    </typeAliases>
</configuration>

实体类User


package com.lxc.domain;
 
import lombok.Data;
 
@Data
public class User {
    private String name;
    private String password;
}

UserMapper 接口


package com.lxc.dao;
 
import com.lxc.domain.User;
import java.util.List;
 
public interface UserMapper {
    public List<User> getList();
}

UserMapperImp 实现接口


package com.lxc.dao;
 
import com.lxc.domain.User;
import org.mybatis.spring.SqlSessionTemplate;
 
import java.util.List;
// 《实现接口的类 UserMapperImp》
// 需要把这个类注入到Spring中去。
public class UserMapperImp implements UserMapper{
    // 我们所有操作都是用sqlSession 来执行的
    private SqlSessionTemplate sqlSession;
    public void setSqlSession(SqlSessionTemplate sqlSession) {
        this.sqlSession = sqlSession;
    }
    @Override
    public List<User> getList() {
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        return userMapper.getList();
    }
}

UserMapper.xml


<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.lxc.dao.UserMapper">
    <select id="getList" resultType="User">
        select * from mybatis
    </select>
</mapper>

第三步

测试


import com.lxc.dao.UserMapper;
import com.lxc.domain.User;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
 
public class Test {
    @org.junit.Test
    public void test() {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("spring-config.xml");
        UserMapper userMapper = ctx.getBean("userMapper", UserMapper.class);
        for (User item : userMapper.getList()) {
            System.out.println(item);
        }
    }
}

输出：