springboot整合mybatis

springboot整合mybatis

1、单纯使用注解进行配置

在pom文件中添加相关依赖

<dependencies>
    <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>1.1.1</version>
    </dependency>
    <!-- mysql -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.46</version>
    </dependency>
    <!-- 单元测试 -->
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
    </dependency>

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

编辑application.properties文件

mybatis.type-aliases-package=cn.xupengzhuang.entity

spring.datasource.driverClassName = com.mysql.jdbc.Driver
spring.datasource.url = jdbc:mysql://localhost:3306/mybatis_db?useUnicode=true&characterEncoding=utf-8
spring.datasource.username = root
spring.datasource.password = root

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。

启动类中添加对mapper包扫描

@SpringBootApplication
@MapperScan("cn.xupengzhuang.mapper")
public class Application {

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

}

在数据库创建一张表，用于测试

CREATE TABLE `user` (
  `user_id` int(10) NOT NULL AUTO_INCREMENT,
  `user_name` varchar(15) NOT NULL,
  `password` varchar(30) NOT NULL,
  `age` int(2) DEFAULT NULL,
  PRIMARY KEY (`user_id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;

根据表的字段，创建实体类

private Integer userId;
    private String userName;
    private String password;
    private Integer age;

    public User() {
    }

    public User(Integer userId, String userName, String password, Integer age) {
        this.userId = userId;
        this.userName = userName;
        this.password = password;
        this.age = age;
    }

    public Integer getUserId() {
        return userId;
    }

    public void setUserId(Integer userId) {
        this.userId = userId;
    }

    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 Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

编写Mapper文件

public interface UserMapper {

    /**
     * 查询所有
     */
    @Select("select * from user")
    @Results({
            @Result(property = "userId",column = "user_id"),
            @Result(property = "userName",column = "user_name")
    })
    List<User> getAllUsers();

    /**
     * 根据主键查询
     */
    @Select("select * from user where user_id = #{id}")
    @Results({
            @Result(property = "userId",column = "user_id"),
            @Result(property = "userName",column = "user_name")
    })
    User getUserById(@Param("id") Integer id);

    /**
     * 添加
     */
    @Insert("insert into user values(#{userId},#{userName},#{password},#{age})")
    int addUser(User user);

    /**
     * 删除
     */
    @Delete("delete from user where user_id = #{id}")
    int deleteUser(@Param("id") Integer id);

    /**
     * 修改
     */
    @Update("update user set user_name=#{userName},password=#{password},age=#{age} where user_id = #{userId}")
    int updateUser(User user);

}

开发Controller

@RestController
public class UserController {

    @Autowired
    private UserMapper userMapper;

    @GetMapping("/getAllUsers")
    public List<User> getAllUsers() {
        return userMapper.getAllUsers();
    }

    @GetMapping("/getUser/{id}")
    public User getUserById(@PathVariable("id") Integer id) {
        return userMapper.getUserById(id);
    }

    /**
     *
     * 请使用接口测试工具进行测试
     */
    @PostMapping("/addUser")
    public String addUser() {
        User user = new User();
        user.setUserName("zxp");
        user.setPassword("666");
        user.setAge(23);

        int i = userMapper.addUser(user);
        if (i > 0) {
            return "success";
        } else {
            return "fail";
        }
    }

    @DeleteMapping("/deleteUser")
    public String deleteUser(){
        int i = userMapper.deleteUser(4);
        if (i>0){
            return "删除成功";
        }else {
            return "删除失败";
        }
    }

    @PutMapping("/updateUser")
    public String updateUser(){
        User user = userMapper.getUserById(1);
        user.setUserName("zxp");
        user.setPassword("999");
        user.setAge(24);

        int i = userMapper.updateUser(user);
        if (i>0){
            return "修改成功";
        }else {
            return "修改失败";
        }

    }



}

以上工作做完后，就可以启动项目，使用接口测试工具进行测试。

 2、XML配置版本

修改application.properties

在上面配置的基础上，增加下面两行

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

然后在resources下创建mybatis文件夹，在mybatis文件夹下创建mybatis-config.xml配置文件，在mybatis文件夹下继续创建mapper文件夹，在这个mapper文件夹下创建UserMapper.xml文件。这两个文件的内容分别如下：

mybatis-config.xml

<?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>

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="cn.xupengzhuang.mapper.UserMapper" >
    <resultMap id="BaseResultMap" type="cn.xupengzhuang.entity.User" >
        <id column="user_id" property="userId" jdbcType="INTEGER" />
        <result column="user_name" property="userName" jdbcType="VARCHAR" />
        <result column="password" property="password" jdbcType="VARCHAR" />
        <result column="age" property="age" jdbcType="INTEGER" />
    </resultMap>

    <!-- 查询所有 -->
    <select id="getAllUsers" resultMap="BaseResultMap"  >
        select * from user
    </select>

    <!-- 根据主键查询 -->
    <select id="getUserById" parameterType="java.lang.Integer" resultMap="BaseResultMap" >
        select * from user where user_id = #{id}
    </select>

    <!-- 添加 -->
    <insert id="addUser" parameterType="cn.xupengzhuang.entity.User" >
        insert into user values(#{userId},#{userName},#{password},#{age})
    </insert>

    <!-- 删除 -->
    <delete id="deleteUser" parameterType="java.lang.Integer" >
        delete from user where user_id = #{id}
    </delete>

    <!-- 修改 -->
    <update id="updateUser" parameterType="cn.xupengzhuang.entity.User" >
        update user set user_name=#{userName},password=#{password},age=#{age} where user_id = #{userId}
    </update>


</mapper>

编写UserMapper文件

public interface UserMapper {

    /**
     * 查询所有
     */
    List<User> getAllUsers();

    /**
     * 根据主键查询
     */
    User getUserById(@Param("id") Integer id);

    /**
     * 添加
     */
    int addUser(User user);

    /**
     * 删除
     */
    int deleteUser(@Param("id") Integer id);

    /**
     * 修改
     */
    int updateUser(User user);

}

编写完后，启动项目，然后就可以使用接口测试进行测试了。