servlet实现登陆出现404，感觉没错是不是哪里潜在的原因

package com.tz.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("Login")
public class Login extends HttpServlet {

   /**
   *
   */
   private static final long serialVersionUID = 1L;

   @Override
   protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       doPost(req,resp);
   }

   @Override
   protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       String username=req.getParameter("username");
       String password=req.getParameter("password");
       if(username!=null&&password!=null&&username.equals("aaa")&&password.equals("1234")){
           req.setAttribute("username", username);
           req.getRequestDispatcher("/welcome").forward(req,resp);
       }else{
           req.getRequestDispatcher("/error").forward(req,resp);
       }
   }
}

package com.tz.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("/welcome")
public class Welcome extends HttpServlet {

   /**
   *
   */
   private static final long serialVersionUID = 1L;

   @Override
   protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       // TODO Auto-generated method stub
       super.doGet(req, resp);
   }

   @Override
   protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       String username=req.getParameter("username");
       PrintWriter out = resp.getWriter();
       out.println("<html>");
       out.println("<head>");
       out.println("<title>登录信息</title>");
       out.println("</head>");
       out.println("<body algin=center>");
        out.println("<h2>"+"歡迎您"+username+"</h2>");
        out.println("</body>");
        out.println("</html>");
    }
}

/**
*
*/
package com.tz.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
* @author Administrator
*
*/
@WebServlet("/error")
public class Error extends HttpServlet {

   /**
   *
   */
   private static final long serialVersionUID = 1L;

   @Override
   protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       doPost(req,resp);
   }

   @Override
   protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       PrintWriter out =resp.getWriter();
           out.println("<html>");
           out.println("<head>");
           out.println("<title>登录信息</title>");
           out.println("</head>");
           out.println("<body algin=center>");
            out.println("<h2>登陆错误请重新登陆</h2>");
            out.println("</body>");
            out.println("</html>");
   }

}

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<style type="text/css">
   #box{width:500px;height:500px;margin:100px auto;}
   #sub{text-align:center}
   #box form div{width:230px;height:40px;line-heihgt:340px}
</style>
</head>
<body>
   <div id="box">
       <h3>聊天室</h3>
       <form action="/land/Login" method="post">
           <div class="text">账号<input type="text" name="username" /></div>
           <div class="pas">密码<input type="password" name="password" /></div>
           <div class="sub"><input type="submit" value="登陆" class="sub"></div>
       </form>
   </div>
</body>
</html>

慕先生4463397

浏览 1228回答 1

1回答

产品经理不是经理

第一个Servlet注解改为：@WebServlet("/Login");表单form里的 action="/land/Login"改为action="${pageContext.request.contextPath}/Login"使用@WebServlet注解的话，就不用在web.xml里面配置Servlet与UrlPattern了。

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