Druid连接池练习

练习描述

完成商品品牌数据的增删改查操作

查询： 查询所有数据

添加： 添加品牌

修改： 根据id修改

删除： 根据id删除

技巧：

alt + 鼠标左键，整列编辑

alt + Insert可以批量导入构造函数、get方法、set方法

操作步骤

1， 获取Connection

2， 定义SQL

3， 获取PreparedStatement对象

4， 设置参数

5， 执行SQL

6， 处理结果：List<Brand>

7， 释放资源

源代码

package local.content.example;import java.io.FileInputStream;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
import com.alibaba.druid.pool.DruidDataSourceFactory;
import local.content.pojo.Brand;
import org.junit.jupiter.api.Test;import javax.sql.DataSource;
import java.sql.Connection;
/*** 测试用例* 品牌数据的增、删、改、查操作*/
public class BrandTest {public static void main(String[] args){BrandTest test1 = new BrandTest();// 测试查询所有品牌信息方法try {test1.testSelectDB();} catch (Exception e) {e.printStackTrace();}// 测试添加品牌信息方法try {test1.testAddBrand();} catch (Exception e) {e.printStackTrace();}// 测试删除品牌信息方法try {test1.testDeleteBrand(3);} catch (Exception e) {e.printStackTrace();}// 测试修改品牌信息方法try {test1.testUpdateBrand();} catch (Exception e) {e.printStackTrace();}}// 修改品牌信息方法@Testpublic void testUpdateBrand() throws Exception {//1， 获取Druid ConnectionProperties prop = new Properties();prop.load(new FileInputStream("jdbc01/src/main/resources/druid.properties"));DataSource dataSource = DruidDataSourceFactory.createDataSource(prop);Connection connection = dataSource.getConnection();System.out.println(connection);//2， 编写SQL语句String sql = "update brand set brandName = ?, companyName = ?, order_id = ? where id = ?";//3， 执行SQL语句PreparedStatement preparedStatement = connection.prepareStatement(sql);preparedStatement.setString(1, "iphone");preparedStatement.setString(2, "苹果公司");preparedStatement.setInt(3, 10);preparedStatement.setString(4, "1");System.out.println(sql);int result = preparedStatement.executeUpdate();if(result > 0) {System.out.println("修改成功");} else {System.out.println("修改失败");}//4， 关闭连接preparedStatement.close();connection.close();}// 删除品牌信息方法@Testpublic void testDeleteBrand(int id) throws Exception {//1， 获取Druid ConnectionProperties prop = new Properties();prop.load(new FileInputStream("jdbc01/src/main/resources/druid.properties"));DataSource dataSource = DruidDataSourceFactory.createDataSource(prop);Connection conn = dataSource.getConnection();//2， 编写SQL语句String sql = "delete from brand where id = ?";//3， 获取PreparedStatementPreparedStatement ps = conn.prepareStatement(sql);//4， 设置参数ps.setInt(1, 3);//5， 执行SQLint count = ps.executeUpdate();//6， 处理结果if (count > 0) {System.out.println("删除成功");} else {System.out.println("删除失败");//7， 释放资源ps.close();conn.close();}}// 添加品牌信息方法@Testpublic void testAddBrand() throws Exception {// 定义要新增的参数内容String brandName = "抖音";String company = "字节跳动";int ordered = 1000;//1， 获取Druid ConnectionProperties prop = new Properties();prop.load(new FileInputStream("jdbc01/src/main/resources/druid.properties"));DataSource dataSource = DruidDataSourceFactory.createDataSource(prop);Connection connection = dataSource.getConnection();//2， 编写SQL语句String sql = "insert into brand (brandName, companyName, order_id) values (?, ?, ?)";//3， 获取PreparedStatementPreparedStatement preparedStatement = connection.prepareStatement(sql);//4， 给占位符赋值preparedStatement.setString(1, brandName);preparedStatement.setString(2, company);preparedStatement.setInt(3, ordered);//5， 执行SQL语句int i = preparedStatement.executeUpdate();//6， 处理结果if (i > 0) {System.out.println("添加成功");} else {System.out.println("添加失败");//7， 释放资源preparedStatement.close();connection.close();}}// 查询品牌信息@Testpublic void testSelectDB() throws Exception {//1， 获取Druid ConnectionProperties prop = new Properties();prop.load(new FileInputStream("jdbc01/src/main/resources/druid.properties"));DataSource dataSource = DruidDataSourceFactory.createDataSource(prop);Connection conn = dataSource.getConnection();//2， 定义SQLString sql = "select * from brand where id >= ?";//3， 获取PreparedStatement对象PreparedStatement pstmt = conn.prepareStatement(sql);//4， 设置参数pstmt.setInt(1,1);//5， 执行SQLResultSet rs = pstmt.executeQuery();//6， 处理结果：List<Brand>List<Brand> brands = new ArrayList<>();Brand brand = null;while(rs.next()){int id = rs.getInt("id");String brandName = rs.getString("brandName");String companyName = rs.getString("companyName");int ordered = rs.getInt("order_id");brand = new Brand(id,brandName,companyName,ordered);brands.add(brand);}System.out.println(brands);//7， 释放资源rs.close();pstmt.close();conn.close();}
}