序言：
此前，我們主要通過XML來書寫SQL和填補(bǔ)對象映射關(guān)系。在SpringBoot中我們可以通過注解來快速編寫SQL并實(shí)現(xiàn)數(shù)據(jù)訪問。（僅需配置：mybatis.configuration.map-underscore-to-camel-case=true）。

具體步驟

1. 引入依賴

在pom.xml 引入ORM框架（Mybaits-Starter）和數(shù)據(jù)庫驅(qū)動（MySQL-Conn）的依賴。

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <!--繼承信息 -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.0.M4</version>
        <relativePath/>
    </parent>

    <!--依賴管理 -->
    <dependencies>
        <dependency> <!--添加Web依賴 -->
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency> <!--添加Mybatis依賴 -->
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>
        <dependency><!--添加MySQL驅(qū)動依賴 -->
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency><!--添加Test依賴 -->
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

2. 添加數(shù)據(jù)源

在application.yml 添加數(shù)據(jù)源，以及開啟Mybaits的駝峰映射功能。

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/socks?useSSL=false
    username: root
    password: root
    driver-class-name: com.mysql.jdbc.Driver

mybatis:
  configuration:
   map-underscore-to-camel-case: true #開啟駝峰映射

3. 編寫數(shù)據(jù)層代碼

// POJO類如下：
public class User {
    private String userId;
    private String username;
    private String password;
    // Getters & Setters ..
}
// 數(shù)據(jù)層代碼如下：
public interface UserMapper {

    @Select("select * from t_user where 1=1")
    List<User> list();

    @Select("select * from t_user where username like #{username}")
    List<User> findByUsername(String username);

    @Select("select * from t_user where user_id like #{userId}")
    User getOne(String userId);

    @Delete("delete from t_user where user_id like #{userId}")
    int delete(String userId);
}

4. 添加數(shù)據(jù)庫記錄

在Navicat 連接本地?cái)?shù)據(jù)庫，隨便打開查詢窗口，復(fù)制下面這段腳本，點(diǎn)擊執(zhí)行即可。

DROP DATABASE IF EXISTS `socks`;
CREATE DATABASE `socks`;
USE `SOCKS`;
DROP TABLE IF EXISTS `t_user`;
CREATE TABLE `t_user` (
  `USER_ID` varchar(50) ,
  `USERNAME` varchar(50) ,
  `PASSWORD` varchar(50) 
) ;

INSERT INTO `t_user` VALUES ('1', 'admin', 'admin');
INSERT INTO `t_user` VALUES ('2', 'yizhiwazi', '123456');

5. 啟動項(xiàng)目

@SpringBootApplication
@MapperScan("com.hehe.mapper")  //掃描Mapper接口
public class MybatisApplication {

    public static void main(String[] args) {
        SpringApplication.run(MybatisApplication.class, args);
    }
}

6. 單元測試

import static org.assertj.core.api.Assertions.assertThat;

@RunWith(SpringRunner.class)
@SpringBootTest
public class MybatisApplicationTest {

    @SuppressWarnings("all")
    @Autowired
    UserMapper userMapper;

    @Test
    public void test_db() {
        //開始進(jìn)行測試
        assertThat(userMapper.list().size()).isGreaterThan(1);
        assertThat(userMapper.getOne("1")).isNotEqualTo(null);
        assertThat(userMapper.getOne("xxx")).isEqualTo(null);
    }
}

文檔資料

源碼下載：SpringBoot+MyBatis+Annotation

專題閱讀：《SpringBoot 布道系列》