Springboot整合mybatis数据库连接池

1.项目的构成（主义mapper层有两个）

2.application.yml的配置（对照自己的数据库进行配置url,root,password）

spring:  datasource:useame: rootpassword: 123456url: jdbc:mysql://localhost:3306/database?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8driver-class-name: com.mysql.cj.jdbc.Drivermybatis:  type-aliases-package: com.jk.pojo  mapper-locations: classpath:mybatis/mapper/*.xml

3.pom.xml的导入

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.3.4.RELEASE</version><relativePath/> <!-- lookup parent from repository --></parent><groupId>com.example</groupId><artifactId>testmybatis</artifactId><version>0.0.1-SNAPSHOT</version><name>testmybatis</name><description>Demo project for Spring Boot</description><properties><java.version>1.8</java.version></properties><dependencies><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>2.1.1</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><scope>runtime</scope></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope><exclusions><exclusion><groupId>org.junit.vintage</groupId><artifactId>junit-vintage-engine</artifactId></exclusion></exclusions></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>

4.实体类的创建
我的数据库中表结构如下：

实体类如下：

import lombok.AllArgsConstructor;import lombok.Data;import lombok.NoArgsConstructor;@Data//无参构造函数@NoArgsConstructor//有参构造函数@AllArgsConstructorpublic class Picture {private String url;private  int tagid;private  int ram;private int size;private  int price;}

5.com.jk.Mapper的创建

import org.apache.ibatis.annotations.Mapper;import org.springframework.stereotype.Repository;import java.util.List;//表名这个注解是mybatis的一个mapper类；也是一个Dao类操作数据库@Mapper@Repositorypublic interface PictureMapper {//查询所有的图片List<Picture> queryPics();Picture getPicture(String url);int updatePic(String url);int delPic(String url);int addPic(Picture pic);}

6.mybatis中的xml文件配置

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="com.jk.mapper.PictureMapper"><select id="queryPics" resultType="Picture">  select * from picture  </select><select id="getPicture" resultType="Picture">select  * from picture where url= #{url}</select><select id="addPic" resultType="Picture">insert into picture(url,tagid,ram,size,price) values (#{url},#{tagid},#{ram},#{size},#{price})</select><select id="delPic" resultType="Picture">delete  from picture where url= #{url}</select></mapper>

7.controller层文件创建

package com.jk.Controller;import com.jk.mapper.PictureMapper;import com.jk.pojo.Picture;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.RestController;import java.util.List;@RestControllerpublic class PictureController {@Autowiredprivate PictureMapper pictureMapper;@GetMapping("/pics")public List<Picture> getPicture(){List<Picture> lits=pictureMapper.queryPics();for(Picture p:lits)System.out.println(p);retu  lits;}}