spring boot + mybatis

一、极简xml版本（mybatis还可以通过注解来实现）

pom配置：

　　 <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <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>2.0.0</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </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>

application.properties 添加相关配置：

mybatis.config-location=classpath:mybatis/mybatis-config.xml
mybatis.mapper-locations=classpath:mybatis/mapper/*.xml
mybatis.type-aliases-package=xu.model

spring.datasource.url=jdbc:mysql://localhost:3306/studyspring?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

　　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。

　　mybatis的配置也需要指明路径,指定了mybatis基础配置文件和实体类映射文件的地址

启动类：

@EnableCaching
@SpringBootApplication
@MapperScan("xu.mapper")
public class MybatisMainApplication {
    public static void main(String[] args) {
        //spring应用启动起来
        SpringApplication.run(MybatisMainApplication.class,args);
    }

}

　　在启动类中添加对mapper包扫描@MapperScan或者直接在Mapper类上面添加注解@Mapper,建议使用@MapperScan。

mybatis-config.xml 配置

<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>

Mapper文件，添加User的映射文件

<mapper namespace="xu.mapper.UserMapper" >
    <resultMap id="BaseResultMap" type="xu.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="xu.enums.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="xu.model.User" >
       INSERT INTO 
               users
               (userName,passWord,user_sex) 
           VALUES
               (#{userName}, #{passWord}, #{userSex})
    </insert>
    
    <update id="update" parameterType="xu.model.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>

java代码部分：

controller类

package xu.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import xu.mapper.UserMapper;
import xu.model.User;

import javax.annotation.Resource;
import java.util.List;

@RestController
public class UserController {

    @Autowired
    @Resource
    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);
    }


}

接口Mapper类

package xu.mapper;


import xu.model.User;

import java.util.List;

public interface UserMapper {
    
    List<User> getAll();
    
    User getOne(Long id);

    void insert(User user);

    void update(User user);

    void delete(Long id);

}

实体类

package xu.model;


import xu.enums.UserSexEnum;

import java.io.Serializable;

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();
    }

}