spring-boot加mybatis实现数据库访问

项目结构

1.maven

<?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>2.1.7.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.zhizous</groupId>
<artifactId>blogs</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>blogs</name>
<description>Demo project for Spring Boot</description>

<properties>
<java.version>1.8</java.version>
</properties>

<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</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>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.0</version>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</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>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.35</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.17</version>
</dependency>
</dependencies>

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>

</project>

 2.Application.class（启动类）

package com.zhizous.blogs;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@MapperScan("com.zhizous.blogs.mapper") //启动时扫描所有的Mapper
@SpringBootApplication
public class BlogsApplication {

public static void main(String[] args) {
SpringApplication.run(BlogsApplication.class, args);
}

}

3.application.yml（配置文件）

server:
port: 8080
servlet: #配置项目的访问路径
context-path: / #(http://localhost/boot)

spring:
datasource: #连接数据的基本配置
username: root
password: admin
url: jdbc:mysql://localhost:3306/blogs?serverTimezone=UTC #设置时区，不然可能会报错
driver-class-name: com.mysql.cj.jdbc.Driver

mybatis:
configuration:
map-underscore-to-camel-case: true #开启驼峰命名转换机制

4.创建一个实体类（music）

package com.zhizous.blogs.bean;

public class Music {

private int id;//id
private String musWriter;//音乐作者
private String musName;//音乐名
private int musTime;//音乐总秒数
private String musSrc;//音乐文件路径
private String musImg;//音乐图片

public String getMusImg() {
return musImg;
}

public void setMusImg(String musImg) {
this.musImg = musImg;
}

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

public String getMusWriter() {
return musWriter;
}

public void setMusWriter(String musWriter) {
this.musWriter = musWriter;
}

public String getMusName() {
return musName;
}

public void setMusName(String musName) {
this.musName = musName;
}

public int getMusTime() {
return musTime;
}

public void setMusTime(int musTime) {
this.musTime = musTime;
}

public String getMusSrc() {
return musSrc;
}

public void setMusSrc(String musSrc) {
this.musSrc = musSrc;
}
}

5.设置mapper

package com.zhizous.blogs.mapper;

import com.zhizous.blogs.bean.Music;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import org.springframework.stereotype.Repository;

import java.util.List;

@Mapper
@Repository
public interface MusicMapper {
//    select * from music where id=#{id}
@Select("select * from music where id = #{id}")
public Music getMusicById(@Param("id") Integer id);

@Select("select * from music")
public List<Music> getMusics();

}

6.设置server

package com.zhizous.blogs.service;

import com.zhizous.blogs.bean.Music;
import com.zhizous.blogs.mapper.MusicMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.List;

@Service
public class MusicService {
@Autowired
MusicMapper musicMapper;

public Music getMusicById(Integer id) {
return musicMapper.getMusicById(id);
}

public List<Music> getMusics(){
return musicMapper.getMusics();
}
}

7.最后设置我们的控制器

package com.zhizous.blogs.controller;
import com.zhizous.blogs.bean.Music;
import com.zhizous.blogs.service.MusicService;
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;

@RestController
@RequestMapping(path = "/music", produces = "application/json;charset=UTF-8")
public class MusicController {

@Autowired
private MusicService musicService;

//@PathVariable Integer id
@RequestMapping("/getmusic")
public Music getMusic(Integer id) {
Music music = musicService.getMusicById(id);
return music;
}

@RequestMapping("/musiclist")
public List<Music> getMusicList() {
List<Music> musics = musicService.getMusics();
return musics;
}

}

 8.浏览器查看结果

9.数据库

转载于:https://www.cnblogs.com/zhizou/p/11384396.html