Spring Boot入门教程2-1、使用Spring Boot+MyBatis访问数据库（CURD）注解版

一、前言

什么是MyBatis？
MyBatis是目前Java平台最为流行的ORM框架
https://baike.baidu.com/item/MyBatis/2824918
本篇开发环境
1、操作系统： Windows 10 X64
2、Java SDK： jdk-8u141
3、Maven：3.5
4、IDE：IntelliJ IDEA 2017
5、Spring Boot：1.5.6

本项目构建基于：https://ken.io/note/springboot-course-basic-helloworld

二、Spring Boot整合MyBatis

引入核心依赖

package	说明
mybatis-spring-boot-starter	MyBatis核心for Spring Boot
mysql-connector-java	用于连接MySQL

pom.xml文件：

<parent>
    <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.6.RELEASE</version> </parent> <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> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.38</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> </dependencies>

配置数据库连接

在配置文件：application.yml中增加以下配置：

spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver url: jdbc:mysql://localhost:3306/course?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf-8 username: mysql password: password

数据库自行创建MySQL下载地址：https://dev.mysql.com/downloads/

Package创建

Package	说明
io.ken.springboot.course.model	用于存放实体
io.ken.springboot.course.dao	用于存放数据访问映射*mapper

user表&实体创建

1、user表创建脚本

DROP TABLE IF EXISTS `user`; CREATE TABLE `user` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(255) DEFAULT NULL, `age` int(11) DEFAULT NULL, `hobby` varchar(500) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;

2、user实体

package io.ken.springboot.course.model;

public class User { private int id; private String name; private int age; private String hobby; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getHobby() { return hobby; } public void setHobby(String hobby) { this.hobby = hobby; } }

getger和setter可以选中类名之后使用快捷键Alt+Insert生成

创建UserMapper，用于User数据库操作映射

package io.ken.springboot.course.dao;

import io.ken.springboot.course.model.User;
import org.apache.ibatis.annotations.*;

import java.util.List;

@Mapper public interface UserMapper { @Select("SELECT * FROM user WHERE id = #{id}") User queryById(@Param("id") int id); @Select("SELECT * FROM user") List<User> queryAll(); @Insert({"INSERT INTO user(name,age,hobby) VALUES(#{name},#{age},#{hobby})"}) int add(User user); @Delete("DELETE FROM user WHERE id = #{id}") int delById(int id); @Update("UPDATE user SET name=#{name},age=#{age},hobby=#{hobby} WHERE id = #{id}") int updateById(User user); }

创建UserController并提供API

package io.ken.springboot.course.controller;

import io.ken.springboot.course.dao.UserMapper;
import io.ken.springboot.course.model.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; import java.util.List; @Controller @RequestMapping("/user") public class UserController { @Autowired UserMapper userMapper; @RequestMapping("/querybyid") @ResponseBody User queryById(int id) { return userMapper.queryById(id); } @RequestMapping("/queryall") @ResponseBody List<User> queryAll() { return userMapper.queryAll(); } @RequestMapping("/add") @ResponseBody String add(User user) { return userMapper.add(user) == 1 ? "success" : "failed"; } @RequestMapping("/updatebyid") @ResponseBody String updateById(User user) { return userMapper.updateById(user) == 1 ? "success" : "failed"; } @RequestMapping("/delbyid") @ResponseBody String delById(int id) { return userMapper.delById(id) == 1 ? "success" : "failed"; } }

API测试

API	示例
添加用户	/user/add?name=tom&age=1&hobby=football
更新用户	/user/updatebyid?name=ken&age=18&hobby=coding&id=1
查询指定用户	/user/querybyid?id=1
查询所有用户	/user/queryall
删除指定用户	/user/delbyid?id=2