import java.io.*;
import org.apache.log4j.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.ResultSet;
public class LoginDemo {
public void execute(String user,String pass){
boolean foo=false;
try{
Class.forName("com.mysql.jdbc.Driver");
Connection con=DriverManager.getConnection("jdbc:mysql://localhost/students","root","");
Statement stam=con.createStatement();
//存在注入攻击漏洞:select * from login where user='' or'x'='x' or 'x'='' and '1'
ResultSet rs=stam.executeQuery("select * from login where user='" + user + "' and pass='"+ pass + "'");
while(rs.next()){
foo=true;
}
if(foo){
System.out.println("登陆成功");
}
else
{
System.out.println("用户名密码错误");
}
}catch(ClassNotFoundException e){
e.printStackTrace();
}catch(SQLException e){
e.printStackTrace();
}
}
public static void main(String[] args){
Logger log=Logger.getLogger(LoginDemo.class);
try{
LoginDemo ld=new LoginDemo();
BufferedReader bf=new BufferedReader(new InputStreamReader(System.in));
log.info("请输入用户名");
String bf_str=bf.readLine();
log.info("请输入密码");
String bf2_str=bf.readLine();
bf.close();
ld.execute(bf_str,bf2_str);
}catch(IOException e){
e.printStackTrace();
}
}
}
当输入用户名的时候输入:' or 'x'='x' or '2'='
密码随便输.....
成功登陆了吧.....