Question

我已尝试添加 Servlet 运行所需的所有库，但我仍然遇到引发HTTP Status 500错误的异常。

我也尝试过堆栈溢出中所有先前提出的问题。

LoginServlet.java

package com.testlogin;

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("/LoginServlet")
public class LoginServlet extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {            
        response.setContentType("text/html");

        String username = request.getParameter("username");
        String password = request.getParameter("password");
        PrintWriter pw = response.getWriter();
        pw.print("Hello");
        if (username.equals(password)) {
            pw.println("<h1>Hello </h1>" + username);
        }            
    }

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

的login.html：

<!DOCTYPE html>
<html>

<head>
  <meta charset="ISO-8859-1">
  <title>Insert title here</title>
</head>

<body>
  <form action="LoginServlet" method="post">
    <div style="color: red">
      User Name
      <input type="text" name="username">
      <br /> Password
      <input type="password" name="password">
      <br>
      <input type="submit" value="Sign In">
    </div>   
  </form>
</body>

</html>

Answer 1

好吧，不要使代码复杂化。我认为您的代码也可以正常工作，问题应该在您的服务器上。请确保您使用的是servlet版本＆gt; 3.0和tomcat 7，因为它不会在先前版本的tomcat中运行试试这个..

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("/LoginServlet")
public class LoginServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {

response.setContentType("text/html");

String username = request.getParameter("username");
String password = request.getParameter("password");
PrintWriter pw = response.getWriter();
pw.print("Hello");
if (username.equals(password)) {
pw.println("<h1>Hello </h1>" + username);
}

}


}

HTTP状态500的未知Servlet异常抛出错误

1 个答案: