springboot集成mybatis

springboot集成mybatis

实现步骤：

1.准备数据库创建表
2.添加起步依赖
3.创建POJO
4.创建mapper接口
5.创建映射文件
6.配置yml 指定映射文件位置
7.创建启动类，加入注解扫描
8.创建service controller 进行测试

1.创建数据库表

-- ----------------------------
-- Table structure for `user`
-- ----------------------------
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`username` varchar(50) DEFAULT NULL,
`password` varchar(50) DEFAULT NULL,
`name` varchar(50) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;
-- ----------------------------
-- Records of user
-- ----------------------------
INSERT INTO `user` VALUES ('1', 'zhangsan', '123', '张三');
INSERT INTO `user` VALUES ('2', 'lisi', '123', '李四');

2.创建工程并添加依赖pom.xml如下参考

<?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>
​
    <groupId>com.guigu</groupId>
    <artifactId>guigu-springboot-mybatis-demo04</artifactId>
    <version>1.0-SNAPSHOT</version>
​
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.4.RELEASE</version>
    </parent>
​
    <dependencies>
        <!--驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <!--mybatis的 起步依赖-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.0.1</version>
        </dependency>
        <!--spring web起步依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
​
    </dependencies>
​
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
​
​
</project>

3.创建pojo

public class User implements Serializable{
    private Integer id;
    private String username;//用户名
    private String password;//密码
    private String name;//姓名
    //getter setter...
    //toString
}

4.创建mapper接口

package com.guigu.dao;
​
import com.guigu.pojo.User;
​
import java.util.List;
​
/***
 * mapper接口
 * @author javaboy
 * @packagename com.guigu.dao
 * @version 1.0
 * @date 2020/2/23
 */
public interface UserMapper {
    public List<User> findAllUser();
}

5.创建UserMapper映射文件，如下图所示

 
​
<?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.guigu.dao.UserMapper">
    <select id="findAllUser" resultType="com.guigu.pojo.User">
        SELECT * from user
    </select>
</mapper>

xml文件放Resource中的mappers文件下

6.创建配置application.yml文件：

spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost/springboot_user?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
    username: root
    password: 123456
#配置mapper的映射文件的位置
mybatis:
  mapper-locations: classpath:mappers/*Mapper.xml

7.创建启动类，加入mapper接口注解扫描

 
​
@SpringBootApplication
@MapperScan(basePackages = "com.guigu.dao")
//MapperScan 用于扫描指定包下的所有的接口，将接口产生代理对象交给spriing容器
public class MybatisApplication {
    public static void main(String[] args) {
        SpringApplication.run(MybatisApplication.class,args);
    }
}

8.创建service 实现类和接口

package com.guigu.service.impl;
​
import com.guigu.dao.UserMapper;
import com.guigu.pojo.User;
import com.guigu.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
​
import java.util.List;
​
/***
 * 描述
 * @author javaboy
 * @packagename com.guigu.service.impl
 * @version 1.0
 * @date 2020/2/23
 */
@Service
public class UserServiceImpl implements UserService {
​
    @Autowired
    private UserMapper userMapper;
​
    @Override
    public List<User> findAllUser() {
        return userMapper.findAllUser();
    }
}

接口如下：

package com.guigu.service.impl;
​
import com.guigu.dao.UserMapper;
import com.guigu.pojo.User;
import com.guigu.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
​
import java.util.List;
​
/***
 * 描述
 * @author javaboy
 * @packagename com.guigu.service.impl
 * @version 1.0
 * @date 2020/2/23
 */
@Service
public class UserServiceImpl implements UserService {
​
    @Autowired
    private UserMapper userMapper;
​
    @Override
    public List<User> findAllUser() {
        return userMapper.findAllUser();
    }
}

9.创建controller

package com.guigu.controller;
​
import com.guigu.pojo.User;
import com.guigu.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
​
import java.util.List;
​
/***
 * 描述
 * @author javaboy
 * @packagename com.guigu.controller
 * @version 1.0
 * @date 2020/2/23
 */
@RestController
@RequestMapping("/user")
public class UserController {
​
    @Autowired
    private UserService userService;
​
    @RequestMapping("/findAll")
    public List<User> findAll(){
        return userService.findAllUser();
    }
}

10.测试

浏览器中发送请求：http://localhost:8080/user/findAll