SpringBoot+maven整合mybatis实现增删改查

第一种方式：SpringBoot整合Mybatis注解开发
首先创建一个maven项目 在pom.xml文件中添加maven的相关依赖

<?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">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.3.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.my.withub</groupId>
<artifactId>springbootmybatis</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.1.1</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.26</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
</dependency>
</dependencies>
</project>

在application.yml文件中添加数据源等相关配置

mybatis:
type-aliases-package: com.my.withub.domain
spring:
datasource:
driverClassName: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/springboot?useUnicode=true&characterEncoding=utf-8
username: root
password: 123456

springboot会自动加载spring.datasource.*相关配置，数据源就会自动注入到sqlSessionFactory中，sqlSessionFactory会自动注入到Mapper中

在启动类中添加对mapper包扫描注解@MapperScan

@SpringBootApplication
@MapperScan("com.my.withub.mapper")
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class,args);
}
}

编写写实体类UserEntity

public class UserEntity implements Serializable {
private static final long serialVersionUID = 1L;
private Long id;
private String userName;
private String passWord;
private UserSexEnum userSex;
private String nickName;

省略构造方法、getter setter以及toString方法
建表语句如下：

CREATE TABLE `users` (
`id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键id',
`userName` varchar(32) DEFAULT NULL COMMENT '用户名',
`passWord` varchar(32) DEFAULT NULL COMMENT '密码',
`user_sex` varchar(32) DEFAULT NULL,
`nick_name` varchar(32) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=28 DEFAULT CHARSET=utf8;

然后编写mapper文件

public interface UserMapper {
@Select("SELECT * FROM users")
@Results({
@Result(property = "userSex",  column = "user_sex", javaType = UserSexEnum.class),
@Result(property = "nickName", column = "nick_name")
})
List<UserEntity> getAll();

@Select("SELECT * FROM users where id=#{id}")
@Results({
@Result(property = "userSex",  column = "user_sex", javaType = UserSexEnum.class),
@Result(property = "nickName", column = "nick_name")
})
UserEntity getOne(Long id);

@Insert("INSERT INTO users(userName,passWord,user_sex,nick_name) VALUES(#{userName}, #{passWord}, #{userSex},#{nickName})")
void insert(UserEntity user);

@Update("update users set userName=#{userName},nick_name=#{nickName} where id=#{id}")
void update(UserEntity user);

@Delete("delete from users where id=#{id}")
void delere(UserEntity user);
}

其中user_sex使用了枚举

public enum UserSexEnum {
MAN, WOMAN
}

@Select注解表示查询，所有的查询均使用这个
@Result 修饰返回的结果集，实体类属性与数据库字段一一对应，如果实体类属性和数据库属性名保持一致，就不需要这个属性来修饰。
@Insert 插入数据，直接传入实体类会自动解析属性到对应的值
@Update 修改数据，也可以直接传入对象
@delete 删除数据
编写Controller

@RestController
public class UserController {
@Resource
private UserMapper userMapper;

@RequestMapping("/add")
public void save(UserEntity user) {
userMapper.insert(user);
}

@RequestMapping("/update")
public void update(UserEntity user) {
userMapper.update(user);
}

@RequestMapping("/delete")
public void delete(UserEntity user) {
userMapper.delere(user);
}

@RequestMapping("/getUser")
public UserEntity  getUser(Long id) {
UserEntity  user=userMapper.getOne(id);
return user;
}

@RequestMapping("/getUsers")
public List<UserEntity> getUsers() {
List<UserEntity> users=userMapper.getAll();
return users;
}

接下来就可以测试了

@RunWith(SpringRunner.class)
@SpringBootTest
public class UserMapperTest {
@Resource
private UserMapper userMapper;

@Test
public void testInsert() throws Exception {
UserEntity user = new UserEntity();
userMapper.insert(new UserEntity("大辉辉", "123456", UserSexEnum.MAN,"dahuihui"));
userMapper.insert(new UserEntity("小灰灰", "123456", UserSexEnum.WOMAN,"xiaohuihui"));
userMapper.insert(new UserEntity("樱桃小丸子", "123456", UserSexEnum.WOMAN,"xiaowanzi"));
}

@Test
public void testUpdate(){
UserEntity users = userMapper.getOne(3L);
System.out.println(users.toString());
users.setUserName("小丸子头");
users.setNickName("xiaowanzitou");
userMapper.update(users);
}

@Test
public void testDelete() {
UserEntity users = userMapper.getOne(32L);
System.out.println(users.toString());
userMapper.delere(users);
}

第二种方式：SpringBoot整合Mybatis配置文件xml开发
pom.xml配置文件和注解开发一致，只需要在application.yml文件中添加如下配置

mybatis.config-location: classpath:mybatis/mybatis-config.xml
mybatis.mapper-locations: classpath:mybatis/mapper/*.xml

在mybatis-config.xml配置文件添加相关配置

<?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>
<typeAliases>
<typeAlias alias="Integer" type="java.lang.Integer" />
<typeAlias alias="Long" type="java.lang.Long" />
<typeAlias alias="HashMap" type="java.util.HashMap" />
<typeAlias alias="LinkedHashMap" type="java.util.LinkedHashMap" />
<typeAlias alias="ArrayList" type="java.util.ArrayList" />
<typeAlias alias="LinkedList" type="java.util.LinkedList" />
</typeAliases>
</configuration>

编写user的mapper映射文件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.my.withub.mapper.UserMapper" >
<resultMap id="BaseResultMap" type="com.my.withub.domain.UserEntity" >
<id column="id" property="id" jdbcType="BIGINT" />
<result column="userName" property="userName" jdbcType="VARCHAR" />
<result column="passWord" property="passWord" jdbcType="VARCHAR" />
<result column="user_sex" property="userSex" javaType="com.my.withub.domain.UserSexEnum"/>
<result column="nick_name" property="nickName" jdbcType="VARCHAR" />
</resultMap>

<sql id="Base_Column_List" >
id, userName, passWord, user_sex, nick_name
</sql>

<select id="getAll" resultMap="BaseResultMap"  >
SELECT
<include refid="Base_Column_List" />
FROM users
</select>

<select id="getOne" parameterType="java.lang.Long" resultMap="BaseResultMap" >
SELECT
<include refid="Base_Column_List" />
FROM users
WHERE id = #{id}
</select>

<insert id="insert" parameterType="com.my.withub.domain.UserEntity" >
INSERT INTO
users
(userName,passWord,user_sex,nick_name)
VALUES
(#{userName}, #{passWord}, #{userSex},#{nickName})
</insert>

<update id="update" parameterType="com.my.withub.domain.UserEntity" >
UPDATE
users
SET
<if test="userName != null">userName = #{userName},</if>
<if test="passWord != null">passWord = #{passWord},</if>
nick_name = #{nickName}
WHERE
id = #{id}
</update>

<delete id="delete" parameterType="java.lang.Long" >
DELETE FROM
users
WHERE
id =#{id}
</delete>
</mapper>

编写Dao层的代码

public interface UserMapper {
List<UserEntity> getAll();

UserEntity getOne(Long id);

void insert(UserEntity user);

void update(UserEntity user);

void delete(Long id);
}

controller与测试代码和注解一致就不贴代码了