第一步：
package com.qq.db;
import java.sql.*;
/** 封装一个数据库的工具类* 通用的获取数据的方法* 提高代码的高重用性* */
public class DBunit {private static final String url = "jdbc:mysql://localhost:3306/qqdb";private static final String user = "root";private static final String password = "6612";//封装了一个公共的获取数据库的连接方法public static Connection getConnection() {Connection conn = null;try {//1.加载驱动类Class.forName("com.mysql.jdbc.Driver");//2.创建数据库的连接（提供url+用户名+密码），向java.sql.DriverManger请求并获取Connection对象conn = DriverManager.getConnection(url,user,password);} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}return conn;}//封装一个查询语句public static ResultSet getQueryResult(String sql) {ResultSet rs = null;try {Connection conn = DBunit.getConnection();Statement stat = conn.createStatement();rs = stat.executeQuery(sql);} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}return rs;}}
第二步：测试
package com.qq;
//封装完之后用类名连接方式连接数据库
import java.sql.*;
import java.sql.DriverManager;
import com.qq.db.DBunit;;public class TestDBC {public static void main(String[] args) {try {Connection conn = DBunit.getConnection();String sql = "select * from t_user";ResultSet rs = DBunit.getQueryResult(sql);//3.2相当于游标while(rs.next()) {//判断是否有下一行System.out.println(rs.getInt("id")+"\t"+rs.getString("name"));//输出数据内容}rs.close();conn.close();} catch (Exception e) {e.printStackTrace();}}}