YueXian

YueXian的博客

0%

SpringBoot-整合MyBatis

发表于 更新于 分类于
本文字数： 11k 阅读时长 ≈ 20 分钟

前言

MyBatis 是一款优秀的持久层框架，它支持定制化 SQL、存储过程以及高级映射。MyBatis 避免了几乎所有的 JDBC 代码和手动设置参数以及获取结果集。MyBatis 可以使用简单的XML或注解来配置和映射原生类型、接口和 Java 的 POJO（Plain Old Java Objects，普通老式 Java 对象）为数据库中的记录。

建库建表

  • 建库
    1
    CREATE DATABASE test;
  • 建表
    1
    2
    3
    4
    5
    6
    7
    8
    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=32 DEFAULT CHARSET=utf8;

pom.xml文件

添加MyBatis依赖和MySQL依赖.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
<?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 https://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>2.1.7.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>com.huzh</groupId>
    <artifactId>springboot-mybatis</artifactId>
    <version>1.0-SNAPSHOT</version>
    <name>springboot-mybatis</name>
    <description>springboot-mybatis</description>

    <properties>
        <java.version>1.8</java.version>
        <mybatis.version>2.1.0</mybatis.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!--mybatis-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>${mybatis.version}</version>
        </dependency>
        <!--mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

实体类

  • 实体类
    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    public class User implements Serializable {
        private static final long serialVersionUID = 1L;
        private Long id;
        private String userName;
        private String passWord;
        private UserSexEnum userSex;
        private String nickName;

        public User() {
            super();
        }

        public User(String userName, String passWord, UserSexEnum userSex) {
            super();
            this.passWord = passWord;
            this.userName = userName;
            this.userSex = userSex;
        }

        public Long getId() {
            return id;
        }

        public void setId(Long id) {
            this.id = id;
        }

        public String getUserName() {
            return userName;
        }

        public void setUserName(String userName) {
            this.userName = userName;
        }

        public String getPassWord() {
            return passWord;
        }

        public void setPassWord(String passWord) {
            this.passWord = passWord;
        }

        public UserSexEnum getUserSex() {
            return userSex;
        }

        public void setUserSex(UserSexEnum userSex) {
            this.userSex = userSex;
        }

        public String getNickName() {
            return nickName;
        }

        public void setNickName(String nickName) {
            this.nickName = nickName;
        }

        @Override
        public String toString() {
            // TODO Auto-generated method stub
            return "userName " + this.userName + ", pasword " + this.passWord + "sex " + userSex.name();
        }
    }
  • 枚举类
    1
    2
    3
    public enum UserSexEnum {
    	MAN, WOMAN
    }

两种整合模式

注解模式

配置mybatis和数据库

1
2
3
4
5
6
7
8
9
spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    username: root
    password: 123456
    url: jdbc:mysql://localhost:3306/test?serverTimezone=GMT
mybatis:
  #这个配置用来指定bean在哪个包里，避免存在同名class时找不到bean
  type-aliases-package: com.huzh.springbootmybatisannotation.model

编写 Mapper 层

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
public interface UserMapper {

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

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

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

    @Update("UPDATE users SET userName=#{userName},nick_name=#{nickName} WHERE id =#{id}")
    void update(User user);

    @Delete("DELETE FROM users WHERE id =#{id}")
    void delete(Long id);
}

创建controller

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
@RestController
public class UserController {

    @Autowired
    private UserMapper userMapper;

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

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

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

    @RequestMapping(value="update")
    public void update(User user) {
        userMapper.update(user);
    }

    @RequestMapping(value="/delete/{id}")
    public void delete(@PathVariable("id") Long id) {
        userMapper.delete(id);
    }
}

xml模式

配置mybatis和数据库

  • 指定了 Mybatis 基础配置文件和实体类映射文件的地址。
    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    spring:
      datasource:
        driver-class-name: com.mysql.jdbc.Driver
        username: root
        password: 123456
        url: jdbc:mysql://localhost:3306/test?serverTimezone=GMT
    mybatis:
      #这个配置用来指定bean在哪个包里，避免存在同名class时找不到bean
      type-aliases-package: com.huzh.springbootmybatisxml.model
      ##检查 mybatis 配置是否存在，一般命名为 mybatis-config.xml
      check-config-location: true
      ##配置文件位置
      config-location: classpath:mybatis/mybatis-config.xml
      ## dao xml 文件地址
      mapper-locations: classpath:mapper/*Mapper.xml
  • mybatis-config.xml 配置
    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    <?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>

添加 User 的映射文件

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
<?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.huzh.springbootmybatisxml.mapper.UserMapper">
    <resultMap id="BaseResultMap" type="com.huzh.springbootmybatisxml.model.User">
        <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.huzh.springbootmybatisxml.enums.UserSexEnum"/>
        <result column="nick_name" property="nickName" jdbcType="VARCHAR"/>
    </resultMap>
    <parameterMap id="user" type="com.huzh.springbootmybatisxml.model.User"/>

    <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" parameterMap="user" >
       INSERT INTO
       		users
       		(userName,passWord,user_sex)
       	VALUES
       		(#{userName}, #{passWord}, #{userSex})
    </insert>

    <update id="update" parameterMap="user" >
        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 Mapper 层

1
2
3
4
5
6
7
8
9
10
11
12
public interface UserMapper {

    List<User> getAll();

    User getOne(Long id);

    void insert(User user);

    void update(User user);

    void delete(Long id);
}

创建Controller

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
@RestController
public class UserController {

    @Autowired
    private UserMapper userMapper;

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

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

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

    @RequestMapping(value = "update")
    public void update(User user) {
        userMapper.update(user);
    }

    @RequestMapping(value = "/delete/{id}")
    public void delete(@PathVariable("id") Long id) {
        userMapper.delete(id);
    }
}

启动类

添加对 mapper 包扫描@MapperScan，可以直接在 Mapper 类上面添加注解@Mapper，建议使用下面那种，不然每个 mapper 要加个注解。

1
2
3
4
5
6
7
8
9
@MapperScan("com.huzh.springbootmybatisxml.mapper")
@SpringBootApplication
public class SpringbootMybatisXmlApplication {

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

}

欢迎关注我的其它发布渠道