Springcloud 学习笔记04-Springboot连接数据库

一、打开user-service微服务

启动类右键Run’UserServiceApplication’或者点击右上方启动

2 Springboot连接Mysql数据库

(1)首先我们将需要的包导入，这几个包都是我们稍后要用到的:

       <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.13</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>5.1.3.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.6</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.0.0</version>
        </dependency> 

(2)在application.yml配置你数据库的信息

主要是在spring下添加datasource

server:
  port: 8201
spring:
  application:
    name: user-service
  datasource:
      url: jdbc:mysql://localhost:3306/day1?serverTimezone=UTC&useSSL=false
      username: root
      password: ******
      driver-class-name: com.mysql.cj.jdbc.Driver
eureka:
  client:
    register-with-eureka: true
    fetch-registry: true
    service-url:
      defaultZone: http://localhost:10086/eureka/

(3)测试是否成功

建立一个controller包，在它下面创建一个TestController类

package com.hztest.controller;

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

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

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

}

然后我们在浏览器端输入：
http://localhost:端口号+路径
http://localhost:8201/getUsers