SpringBoot MyBatis简单快速入门例子

MyBatis 是一款优秀的持久层框架，它支持自定义 SQL、存储过程以及高级映射。MyBatis 免除了几乎所有的 JDBC 代码以及设置参数和获取结果集的工作。MyBatis 可以通过简单的 XML 或注解来配置和映射原始类型、接口和 Java POJO（Plain Old Java Objects，普通老式 Java 对象）为数据库中的记录。

1、MyBatis工程总体目录结构

2、创建简单的SpringBoot工程

3、添加MyBatis依赖

<!--MyBatis--><dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.32</version></dependency><dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.4.6</version></dependency>

4、在数据库创建USER表

CREATE TABLE `user` ( `id` int(11) NOT NULL AUTO_INCREMENT, `username` varchar(20) NOT NULL DEFAULT ’’ COMMENT ’用户名’, `password` varchar(50) NOT NULL DEFAULT ’’ COMMENT ’密码’, PRIMARY KEY (`id`) USING BTREE) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 ROW_FORMAT=DYNAMIC;

5、在application.properties配置数据库连接信息

#数据库相关配置spring.datasource.driver-class-name=com.mysql.jdbc.Driverspring.datasource.url=jdbc:mysql://127.0.0.1:3306/test?useSSL=false&characterEncoding=utf8&allowMultiQueries=true&serverTimezone=Asia/Shanghai&useAffectedRows=truespring.datasource.username=rootspring.datasource.password=QQ796413#mybaits配置#mapper加载路径mybatis.mapper-locations= classpath:mapper/*.xml#实体包位置mybatis.type-aliases-package= com.example.mybatisdemo.entity#myatbis配置文件mybatis.config-location= classpath:mybatis-config.xml

6、创建USER表对应的实体类

package com.example.mybatisdemo.entity;public class User { private int id; private String username; private String password; public int getId() {return id; } public void setId(int 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; } @Override public String toString() {return 'User{' +'id=' + id +', username=’' + username + ’’’ +', password=’' + password + ’’’ +’}’; }

7、在mapper/UserMapper创建UserMapper.java

package com.example.mybatisdemo.mapper;import com.example.mybatisdemo.entity.User;import org.apache.ibatis.annotations.Mapper;@Mapperpublic interface UserMapper{ User findUserById(Integer id);}

8、在service/UserService新建UserService.java

package com.example.mybatisdemo.service;import com.example.mybatisdemo.entity.User;public interface UserService { User findUserById(Integer id);}

9、在service/impl/UserServiceImpl 创建UserServiceImpl.java

package com.example.mybatisdemo.service.impl;import com.example.mybatisdemo.entity.User;import com.example.mybatisdemo.mapper.UserMapper;import com.example.mybatisdemo.service.UserService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;@Servicepublic class UserServiceImpl implements UserService {@Autowiredprivate UserMapper userMapper;@Overridepublic User findUserById(Integer id) { return userMapper.findUserById(id);}}

10、在resources下新建mybatis-conf.xml

<?xml version='1.0' encoding='UTF-8' ?><!DOCTYPE configurationPUBLIC '-//mybatis.org//DTD Config 3.0//EN''http://mybatis.org/dtd/mybatis-3-config.dtd'><configuration> <settings><!--开启日志--><setting name='logImpl' value='STDOUT_LOGGING'/><!--开启驼峰命名法--><setting name='mapUnderscoreToCamelCase' value='true'/><!--开启全局延迟加载--><setting name='lazyLoadingEnabled' value='true'/><!-- 集合为空时强制返回空集合实例而不是null --><setting name='returnInstanceForEmptyRow' value='true'/><!-- 结果集中value为空时保留key --><setting name='callSettersOnNulls' value='true'/> </settings></configuration>

11、在resources下mapper文件下创建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'><!--注意：1.这里的namespace要是你usermapper的位置--><mapper namespace='com.example.mybatisdemo.mapper.UserMapper'> <!--注意这里的返回类型--> <resultMap type='com.example.mybatisdemo.entity.User'><result column='id' property='id'/><result column='username' property='username'/><result column='password' property='password'/> </resultMap> <!--2.id和你的方法名一样，resultMap为上面的id名一致--> <select resultMap='BaseResultMap'>select id, username, passwordfrom userwhere id= #{id,jdbcType=INTEGER} </select></mapper>

12、创建UserController.java

package com.example.mybatisdemo.controller;import com.example.mybatisdemo.entity.User;import com.example.mybatisdemo.service.UserService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.bind.annotation.RestController;@RestControllerpublic class UserController { @Autowired UserService userService; @GetMapping('/findUserById') public User findUserById(@RequestParam Integer id){ return userService.findUserById(1); }}

13、测试

工程可以去我的资源下载

到此这篇关于SpringBoot MyBatis快速入门-简单例子的文章就介绍到这了,更多相关SpringBoot MyBatis入门内容请搜索好吧啦网以前的文章或继续浏览下面的相关文章希望大家以后多多支持好吧啦网！