时间戳

首页 > 解决方案 > HTTP 状态 500 ? 内部服务器错误号格式异常

java - HTTP 状态 500 ? 内部服务器错误号格式异常

问题描述

这是servlet文件，当我运行它时，会抛出numberformatexception，client是这里的类。
当我们将数据放入字段时输出错误，不知道该怎么办。因为我已经尝试了所有方法，但它仍然无法正常工作。当我们在这里发布代码时。您可以查看它。*

    Type Exception Report
    Message null
    Description The server encountered an unexpected condition that prevented it from fulfilling the request.
    Exception
        java.lang.NumberFormatException: null
        java.lang.Integer.parseInt(Unknown Source)
        java.lang.Integer.parseInt(Unknown Source)
        emlakcontroller.ClientServlet.doPost(ClientServlet.java:53)
        javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
        javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
        org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    Note The full stack trace of the root cause is available in the server logs.

ClientServlet.java

    /**
    * Servlet implementation class ClientServlet
   */ 
    @WebServlet("/register")
    public class ClientServlet extends HttpServlet {
        private static final long serialVersionUID = 1L;
        private ClientDAO clientDao=new ClientDAO();
        /**
         * @see HttpServlet#HttpServlet()
         */
        public ClientServlet() 
        {
            super();
            // TODO Auto-generated constructor stub
        }
    
        /**
         * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
         */
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
        {
            // TODO Auto-generated method stub
            response.getWriter().append("Served at: ").append(request.getContextPath());
        }
        /**
         * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
         */
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
        {   
            response.setContentType("text/html");  
            PrintWriter out = response.getWriter();     
            String name=request.getParameter("name");
            String email=request.getParameter("email");  
            String password=request.getParameter("password");  
            int contact=Integer.parseInt(request.getParameter("contact"));  
            Client client=new Client();
            client.setName(name);
            client.setEmail(email);
            client.setPassword(password);
            client.setContact(contact); 
            try 
            {
                clientDao.registerClient(client);
            } catch (ClassNotFoundException e)
              {
                // TODO Auto-generated catch block
                e.printStackTrace();
              }
              out.print("Yahoo! register successful");  
              RequestDispatcher rd=request.getRequestDispatcher("SignupFront.html");  
              rd.include(request,response); 
        }
    }

标签： javaeclipsetomcatweb-applicationsnumberformatexception

解决方案

返回的堆栈跟踪应该足以解决此问题。

正如您在其中看到的，可以注意到以下内容：

Exception
        java.lang.NumberFormatException: null

这有效地告诉您，由于值为 ，转换为数字失败null。从您提供的代码中，唯一可行的地方如下：

int contact=Integer.parseInt(request.getParameter("contact"));

因此，您应该执行以下操作：

  1. 确保request.getParameter("contact")返回一个非空值。
  2. 确保request.getParameter("contact")返回一个可以解析为 的值Integer，否则该过程将失败并出现相同的错误。

推荐阅读