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

本文代码示例:https://github.com/ken-io/springboot-course/tree/master/chapter-02-01


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