mybatis-spring-boot-starter主要有两种解决方案,一种是使用注解,一种是使用XML。
参考这篇文章动手跑了一个例子,稍微不同之处,原文是spring boot,这里改成了spring boot 2,mybatis现在最新版本为1.3.2。
一、使用注解
1、添加相关maven文件
<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>1.3.2</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
</dependency>
mybatis-spring-boot-starter最新版本可在官网查询
http://www.mybatis.org/spring-boot-starter/mybatis-spring-boot-autoconfigure/index.html
2、application.properties 添加相关配置
mybatis.type-aliases-package = com.example.demo.entity
spring.datasource.driverClassName = com.mysql.jdbc.Driver
spring.datasource.url = jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8
spring.datasource.username = root
spring.datasource.password =
3、实体类User.java
package com.example.demo.entity;
import com.example.demo.enums.UserSexEnum;
public class User {
public User() {
super();
}
public User(String name, UserSexEnum sex) {
super();
this.name = name;
this.sex = sex;
}
private Integer id;
private String name;
private UserSexEnum sex;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name == null ? null : name.trim();
}
public UserSexEnum getSex() {
return sex;
}
public void setSex(UserSexEnum sex) {
this.sex = sex;
}
@Override
public String toString() {
return "name " + this.name + ", sex " + this.sex;
}
}
4、枚举UserSexEnum.java
package com.example.demo.enums;
public enum UserSexEnum {
MAN,
WOMAN
}
5、启动类中添加对mapper包扫描@MapperScan,这样就不需要在每个Mapper类上面添加注解@Mapper。
package com.example.demo;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
@SpringBootApplication
@MapperScan("com.example.demo.mapper")
public class DemoApplication extends SpringBootServletInitializer {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
6、开发Mapper
package com.example.demo.mapper;
import java.util.List;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import com.example.demo.entity.User;
import com.example.demo.enums.UserSexEnum;
public interface UserMapper {
@Select("SELECT * FROM user")
//结果集,关联实体类属性和数据库字段一一对应,如果两边一致,就不需要这个属性来修饰。
@Results({
@Result(property = "sex", column = "sex", javaType = UserSexEnum.class),
})
List<User> getAll();
@Select("SELECT * FROM user WHERE id = #{id}")
@Results({
@Result(property = "sex", column = "sex", javaType = UserSexEnum.class),
})
User getOne(Long id);
@Insert("INSERT INTO user(name,sex) VALUES(#{name}, #{sex})")
void insert(User user);
@Update("UPDATE user SET name=#{name} WHERE id =#{id}")
void update(User user);
@Delete("DELETE FROM user WHERE id =#{id}")
void delete(Long id);
}
7、单元测试
package com.example.demo.mapper;
import java.util.List;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import com.example.demo.entity.User;
import com.example.demo.enums.UserSexEnum;
@RunWith(SpringRunner.class)
@SpringBootTest
public class UserMapperTest {
@Autowired
private UserMapper UserMapper;
@Test
public void testInsert() throws Exception {
UserMapper.insert(new User("aa", UserSexEnum.MAN));
UserMapper.insert(new User("bb", UserSexEnum.WOMAN));
UserMapper.insert(new User("cc", UserSexEnum.WOMAN));
Assert.assertEquals(3, UserMapper.getAll().size());
}
@Test
public void testQuery() throws Exception {
List<User> users = UserMapper.getAll();
if(users==null || users.size()==0){
System.out.println("is null");
}else{
System.out.println(users.toString());
}
}
@Test
public void testUpdate() throws Exception {
User user = UserMapper.getOne(6l);
System.out.println(user.toString());
user.setName("dd");
UserMapper.update(user);
Assert.assertTrue(("dd".equals(UserMapper.getOne(6l).getName())));
}
}
8、控制层
package com.example.demo.web;
import java.util.List;
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 com.example.demo.entity.User;
import com.example.demo.mapper.UserMapper;
@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);
}
}
项目目录结构:
二、使用XML
1、application.properties新增以下配置
mybatis.config-location = classpath:mybatis/mybatis-config.xml
mybatis.mapper-locations = classpath:mybatis/mapper/*.xml
2、在resources/mybatis目录下添加mybatis-config.xml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>
<settings>
<!-- 控制台打印查询语句 -->
<setting name="logImpl" value="STDOUT_LOGGING" />
</settings>
<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>
3、在resources/mybatis/mapper目录下添加映射文件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.example.demo.mapper.UserMapper" >
<resultMap id="BaseResultMap" type="com.example.demo.entity.User" >
<id column="id" property="id" jdbcType="BIGINT" />
<result column="name" property="name" jdbcType="VARCHAR" />
<result column="sex" property="sex" javaType="com.example.demo.enums.UserSexEnum"/>
</resultMap>
<sql id="Base_Column_List" >
id, name, sex
</sql>
<select id="getAll" resultMap="BaseResultMap" >
SELECT
<include refid="Base_Column_List" />
FROM user
</select>
<select id="getOne" parameterType="java.lang.Long" resultMap="BaseResultMap" >
SELECT
<include refid="Base_Column_List" />
FROM user
WHERE id = #{id}
</select>
<insert id="insert" parameterType="com.example.demo.entity.User" >
INSERT INTO
user
(name,sex)
VALUES
(#{name}, #{sex})
</insert>
<update id="update" parameterType="com.example.demo.entity.User" >
UPDATE
user
SET
name = #{name}
WHERE
id = #{id}
</update>
<delete id="delete" parameterType="java.lang.Long" >
DELETE FROM
user
WHERE
id =#{id}
</delete>
</mapper>
4、编写Dao层的代码
package com.example.demo.mapper;
import java.util.List;
import com.example.demo.entity.User;
public interface UserMapper {
List<User> getAll();
User getOne(Long id);
void insert(User user);
void update(User user);
void delete(Long id);
}