Springboot连接数据库

好家伙，

这里使用的软件是IDEA 2021

1.新建项目

2.更改配置项目文件目录

更改前:

更改后:

2.1.更改pom.xml文件

在该文件中添加:

    <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
    </dependency>    

2.2.更改配置application.properties文件

spring.datasource.url=jdbc:mysql://127.0.0.1:3306/test    //按你说的数据库名字改
spring.datasource.username=root   //按你的的数据库用户名改,一般都是'root'
spring.datasource.password=root   //按你的的数据库密码改
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.max-idle=10
spring.datasource.max-wait=10000
spring.datasource.min-idle=5
spring.datasource.initial-size=5

server.port=8011
server.session.timeout=10
server.tomcat.uri-encoding=UTF-8

2.3.更改配置TestController文件:

代码如下:

package com.example.demo.controller;   //按文件的实际路径来写

import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/mydb")
public class TestController {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @RequestMapping("/getUsers")
    public List<Map<String, Object>> getDbType(){
        String sql = "select * from appuser";
        List<Map<String, Object>> list =  jdbcTemplate.queryForList(sql);
        for (Map<String, Object> map : list) {
            Set<Entry<String, Object>> entries = map.entrySet( );
            if(entries != null) {
                Iterator<Entry<String, Object>> iterator = entries.iterator( );
                while(iterator.hasNext( )) {
                    Entry<String, Object> entry =(Entry<String, Object>) iterator.next( );
                    Object key = entry.getKey( );
                    Object value = entry.getValue();
                    System.out.println(key+":"+value);
                }
            }
        }
        return list;
    }

    @RequestMapping("/user/{id}")
    public Map<String,Object> getUser(@PathVariable String id){
        Map<String,Object> map = null;

        List<Map<String, Object>> list = getDbType();

        for (Map<String, Object> dbmap : list) {

            Set<String> set = dbmap.keySet();

            for (String key : set) {
                if(key.equals("id")){
                    if(dbmap.get(key).equals(id)){
                        map = dbmap;
                    }
                }
            }
        }

        if(map==null)
            map = list.get(0);
        return map;
    }

}

TestController

2.4.更改配置主启动程序DemoApplication文件

代码如下:

package com.example.demo;  //按文件的实际路径来写

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemoApplication {

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

}

3.mysql新建表

spring boot这边基本上搞定了,

前往mysql workbench

3.1.添加一个名为appuser的表

并在其中设置'id','name','password'等属性

中填一点数据用于测试

4.前往spring boot 中启动主程序

启动主程序DemoApplication

点击进入localhost:8011/mydb/getUsers

不出意外的话，应该是出不了什么意外了

搞定！！

That's all