后端开发之用Mybatis简化JDBC的开发快速入门2024及数据库连接池技术和lombok工具详解

package com.bigdate.mybatis;
 
 
import com.bigdate.mybatis.mapper.UserMapper;
import com.bigdate.mybatis.pojo.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
 
import java.sql.*;
import java.util.ArrayList;
import java.util.List;
 
@SpringBootTest //springboot整合单元测试的注解
class MybatisApplicationTests {
 
  @Autowired
  private UserMapper userMapper;
 
  @Test
  public void testListUser(){
    List<User> userList = userMapper.list();
    userList.stream().forEach(user -> {
      System.out.println(user);
    });
  }
 
  @Test
  public void testJdbc() throws Exception {
    //1. 注册驱动
    Class.forName("com.mysql.cj.jdbc.Driver");
 
    //2. 获取连接对象
    String url = "jdbc:mysql://localhost:3306/mybatis";
    String username = "root";
    String password = "123456";
    Connection connection = DriverManager.getConnection(url, username, password);
 
    //3. 获取执行SQL的对象Statement,执行SQL,返回结果
    String sql = "select * from user";
    Statement statement = connection.createStatement();
    ResultSet resultSet = statement.executeQuery(sql);
 
    //4. 封装结果数据
    List<User> userList = new ArrayList<>();
    while (resultSet.next()){
      int id = resultSet.getInt("id");
      String name = resultSet.getString("name");
      short age = resultSet.getShort("age");
      short gender = resultSet.getShort("gender");
      String phone = resultSet.getString("phone");
 
      User user = new User(id,name,age,gender,phone);
      userList.add(user);
    }
 
    //5. 释放资源
    statement.close();
    connection.close();
  }
}

spring.datasource.type=com.alibaba.druid.pool.DruidDataSource

<!-- druid连接池 -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.2.8</version>
</dependency>

spring.datasource.type=com.alibaba.druid.pool.DruidDataSource

<!-- lombok -->
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
</dependency>

package com.bigdate.mybatis.pojo;
 
import lombok.*;
 
//@Getter
//@Setter
//@ToString
//@EqualsAndHashCode
 
@Data
@NoArgsConstructor  //无参构造
@AllArgsConstructor //带参构造
 
public class User {
    private Integer id;
    private String name;
    private Short age;
    private Short gender;
    private String phone;
    
}