springboot项目搭建0051-通用mapper使用mapper.xml

以你之姓@ 2022-03-31 13:16 571阅读 0赞

项目地址：[https://github.com/wenrongyao/springboot-demo.git][https_github.com_wenrongyao_springboot-demo.git]

摘要：mybatis是优秀的持久化框架，但是引入mybatis后还要频繁的写增删改查，很不方便，所以这边引入刘增辉老师的通用mapper，通用mapper封装了单表基本上所有的操作。当联表操作的时候，还是需要写sql的，这边帖子主要讲述在通用mapper的基础上使用mapper.xml。

1、在resource文件夹下建立mapper（可以换名和资源文件配置对应即可），并建立mapper.xml文件，写法和mybatis一样

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dyb25neWFv_size_16_color_FFFFFF_t_70][]  
 2 、资源文件配置

#mybatis xml文件位置
    mybatis.mapper-locations=classpath:mapper/*.xml,classpath:mapper/*/*.xml
    #配置驼峰转下划线（数据库的下划线和model的驼峰自动转换）
    mybatis.configuration.map-underscore-to-camel-case=true

3、测试类SysUserMapper，自己新建的方法不要和通用mapper重名。

import com.honor.config.Mapper2;
    import com.honor.model.sys.SysRole;
    import com.honor.model.sys.SysUserRole;
    
    import java.util.List;
    
    /**
     * 角色mapper
     *
     * @author rongyaowen
     * @create 2018-12-08 16:39
     **/
    public interface SysUserRoleMapper extends Mapper2<SysUserRole> {
    
        public List<SysRole> getConfigedRoleList(Integer sysUserId);
    }

4、测试xml SysUserMapper.xml(名称要和mapper接口一致)

<?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.honor.mapper.SysUserMapper">
    
        <select id="getAllUsers" resultType="com.honor.model.SysUser">
            select * from sys_user;
        </select>
    
    </mapper>

5、测试类

import com.honor.mapper.SysUserMapper;
    import com.honor.model.SysUser;
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.test.context.SpringBootTest;
    import org.springframework.test.context.junit4.SpringRunner;
    import org.springframework.test.context.web.WebAppConfiguration;
    
    import java.util.List;
    
    /**
     * Created by rongyaowen
     * on 2019/1/3.
     */
    @RunWith(SpringRunner.class)
    @SpringBootTest
    @WebAppConfiguration
    public class Mapper2Test {
        @Autowired
        private SysUserMapper sysUserMapper;
    
        @Test
        public void getAllUsersTest() {
            List<SysUser> sysUsers = sysUserMapper.getAllUsers();
            for (SysUser sysUser : sysUsers) {
                System.out.println(sysUser);
            }
        }

6、结果

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dyb25neWFv_size_16_color_FFFFFF_t_70 1][]

[https_github.com_wenrongyao_springboot-demo.git]: https://github.com/wenrongyao/springboot-demo.git
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dyb25neWFv_size_16_color_FFFFFF_t_70]: /images/20220331/fbc4e9b16e604ee998a27883a0c50209.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dyb25neWFv_size_16_color_FFFFFF_t_70 1]: /images/20220331/b191499a6e084116a0c7bf81f0e55dce.png