pom.xml

<dependencies>
        <dependency>
            <!-- jdbcweb -->
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <!-- jdbc -->
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jdbc</artifactId>
        </dependency>
        <dependency>
            <!-- jdbc -->
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <!-- thymeleaf -->
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>

        <dependency>
            <!-- mysql -->
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <!-- 热启动 -->
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

application.yml配置

spring:
  datasource:
    username: koa2weibo
    password: passMYblog123
    url: jdbc:mysql://rm-uf6t9m0yx22dxrya5no.mysql.rds.aliyuncs.com:3306/koa2weibo?serverTimezone=Asia/Shanghai&useSSL=true&useUnicode=true&characterEncoding=UTF8
    driver-class-name: com.mysql.cj.jdbc.Driver

test写一个测试类

package com.xuwen;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;

@SpringBootTest
class Springboot04DataApplicationTests {
    //spring data自带方法，注解，自动注入！-->开发全靠springboot
    @Autowired
    DataSource dataSource;

    @Test
    void contextLoads() throws SQLException {
        //查看一下数据源=>springboot使用：class com.zaxxer.hikari.HikariDataSource
        System.out.println(dataSource.getClass());
        //获得数据库连接
        Connection conn = dataSource.getConnection();
        System.out.println(conn);

        //xxxTemplate,springboot写好的，模版=bean，拿来即用,jdbcTemplate,redisTemplate

        //关闭数据
        conn.close();
    }



}

写一个controller，controller类测试一下。

package com.xuwen.controller;

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

import java.util.List;
import java.util.Map;

/**
 * author:xuwen
 * Created on 2021/8/3
 */


@RestController
public class JDBCController {


    @Autowired
    JdbcTemplate jdbcTemplate;

    //查询数据库的所有信息，并显示在网页上
    //目前没有写，实体类pojo，数据库中的东西，如何获取？-->万能的Map
    @GetMapping("/userList")
    public List<Map<String ,Object>> userList(){
        String sql = "select * from user";
        List<Map<String, Object>> list_maps = jdbcTemplate.queryForList(sql);
        return list_maps;
    }







}

前端页面查到数据库返回的信息

JDBC--spring风装版本

package com.xuwen.controller;

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

import java.util.List;
import java.util.Map;

/**
 * author:xuwen
 * Created on 2021/8/3
 */


@RestController
public class JDBCController {


    @Autowired
    JdbcTemplate jdbcTemplate;

    //查询数据库的所有信息，并显示在网页上
    //目前没有写，实体类pojo，数据库中的东西，如何获取？-->万能的Map
    @GetMapping("/userList")
    public List<Map<String ,Object>> userList(){
        String sql = "select * from user";
        List<Map<String, Object>> list_maps = jdbcTemplate.queryForList(sql);
        return list_maps;
    }

    //增加一个用户
    @GetMapping("/addUser")
    public String addUser(){
        String sql = "insert into koa2weibo.user(id,name,pwd) values(7,'大高个','66d6d')";
        jdbcTemplate.update(sql);
        return "add->ok";
    }



    //改加一个用户
    @GetMapping("/updateUser/{id}")
    public String updateUser(@PathVariable("id") int id){
        String sql = "update koa2weibo.user set name=?, pwd=?  where id="+id;
        //数据需要封装一下
         Object[] obj = new Object[2];
         obj[0]="小明2";
         obj[1]="zzzpas221";
        jdbcTemplate.update(sql,obj);
        return "update->ok";
    }

    //删加一个用户
    @GetMapping("/delUser/{id}")
    public String delUser(@PathVariable("id") int id){
        String sql = "delete from koa2weibo.user where id = ?";
        jdbcTemplate.update(sql,id);
        return "del->ok";
    }


    }