版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/Haidaiya/article/details/82973515
1 原理
Java DataBase Connectivity(JDBC)
2 导包
3 单元测试
4 JDBC测试登录功能(分2步校验和防止SQL注入)
package com.haidai.test;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class LoginTest {
public static void main(String[] args) {
try {
Login("wanglei","wanglei");
} catch (ClassNotFoundException | SQLException e) {
e.printStackTrace();
}
}
public static void Login(String uname,String upassword) throws ClassNotFoundException, SQLException {
//1.加载驱动
Class.forName("com.mysql.jdbc.Driver");
//2.获得连接
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/web_08", "root", "root");
//3.书写sql语句
String sql = "select * from tbl_user where uname=? and upassword=?";
//4.获得语句执行的对象
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setString(1, uname);
pstmt.setString(2, upassword);
//5.执行语句
ResultSet rs = pstmt.executeQuery();
//6.处理结果集
if(rs.next()) {
System.out.println(uname+" 您好!登录成功");
}else {
System.out.println("请检查用户名或密码!");
}
//7.关闭资源
if(rs!=null) rs.close();
if(pstmt!=null) pstmt.close();
if(conn!=null) conn.close();
}
}
代码中解释的很清楚,为了方便自己记忆,7个步骤,4个对象。
DriverManager
Connection
PreparedStatement
ResultSet