1.完整工程目錄圖如下

2.開啟idea,左上角 file–>new–>project–>選擇spring Initializar,選擇 jdk ,然後next

3,出現下圖,繼續next,這裡可以修改你想要的檔名

4.只選中web,next
5.可以工程名,和工程存放的資料夾,點選next之後,等待
6.開啟pom.xml 新增如下依賴

<!--連線資料庫驅動-->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
		</dependency>
		<!--支援通過jdbc連線資料庫-->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-jdbc</artifactId>
		</dependency>
 

7.在application.properties檔案裡進行連線mysql資料庫的配置

spring.datasource.url=jdbc:mysql://localhost:3306/mytime?characterEncoding=utf-8&serverTimezone=GMT%2B8
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

8.在mytime(資料庫名),新建一個t_user表,並新增兩條資料

-- 建表語句:
CREATE TABLE `t_user` (
  `login_name` varchar(255) DEFAULT NULL COMMENT '登入名',
  `password` varchar(255) DEFAULT NULL COMMENT '密碼',
  `phone` varchar(255) DEFAULT NULL COMMENT '手機號碼',
  `email` varchar(255) DEFAULT NULL COMMENT '郵箱',
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT 'id',
  KEY `id` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;
-- 新增資料
INSERT INTO `t_user` VALUES ('ning', '202CB962AC59075B964B07152D234B70', '17730012680', '
 
[email protected]', '1');
INSERT INTO `t_user` VALUES ('郭靖', '202CB962AC59075B964B07152D234B70', '18656004522', '[email protected]', '2');

9.在com.example.demo下新建包 entity,建立t_user的實體類

package com.example.demo.entity;

public class PubUser {
    private String loginName;
    private String password;
    private String phone;
    private String email;
    private String id;

    public PubUser() {
    }

    public String getLoginName() {
        return loginName;
    }

    public void setLoginName(String loginName) {
        this.loginName = loginName;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getId() {
        return id;
    }

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

10.在test 檔案下的DemoApplicationTests類下寫測試方法

package com.example.demo;

import com.example.demo.entity.PubUser;
import org.junit.Test;
import org.junit.runner.RunWith;

import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.test.context.junit4.SpringRunner;

import javax.annotation.Resource;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

@RunWith(SpringRunner.class)
@SpringBootTest
public class DemoApplicationTests {

	@Resource
	private JdbcTemplate jdbcTemplate;
	@Test
	public void contextLoads() {
	}

	@Test
	public void testMysql(){
		String sql = " select login_name,email from t_user" ;
		List<PubUser> userlist = jdbcTemplate.query(sql, new RowMapper<PubUser>() {
			@Override
			public PubUser mapRow(ResultSet resultSet, int i) throws SQLException {
				PubUser user = new PubUser();
				user.setLoginName(resultSet.getString("login_name"));
				user.setEmail(resultSet.getString("email"));
				return user;
			}
		});
		System.out.println("查詢成功");
		for (PubUser user:userlist) {
			System.out.println("使用者名稱為"+user.getLoginName()+"的郵箱是"+user.getEmail());
		}
 	}
}

11.執行步驟
選中要測試的方法,右擊,選則 run testMysql,效果如下,即大功告成