java.lang.nullpointerexception
小白求助,在编译servlet出现了如题的报错 代码如下 这里一个登录验证的处理 在线等
纠结了我好久
//用户验证
package com.yxl;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LoginCl extends HttpServlet{
public void doGet(HttpServletRequest req , HttpServletResponse res)
throws ServletException, IOException {
res.setContentType("text/html;charset=UTF-8");
//接受
String u = req.getParameter("username");
String p = req.getParameter("password");
if(u.equals("yxl")&&p.equals("123")){
//合法
res.sendRedirect("wel?uname="+u); //把username传递给wel界面
}else{
//不合法
res.sendRedirect("login");
}
}
public void doPost(HttpServletRequest req , HttpServletResponse res)
throws ServletException, IOException {
this.doGet(req,res);
}
}