Java servlet未在SubmitComplete上启动（Google应用程序引擎）_Java_Google App Engine_Servlets_Gwt

Java servlet未在SubmitComplete上启动（Google应用程序引擎）

java google-app-engine servlets gwt

Java servlet未在SubmitComplete上启动（Google应用程序引擎）,java,google-app-engine,servlets,gwt,Java,Google App Engine,Servlets,Gwt,GWT 2.5.1/ 应用程序引擎SDK 1.8.9 我试图将一个.CVS文件上传到一个servlet，以便使用FormPanel进行解析，但是我没有从servlet得到任何响应客户端代码我从onSubmit（）中看到窗口，但onSubmitComplete没有响应 web.xml relvant web.xml代码上传的CSVParser ca.ubc.cs310.gwt.healthybc.server.UploadedCSVParser 上传的CSVParser /healthyb

GWT 2.5.1/ 应用程序引擎SDK 1.8.9

我试图将一个.CVS文件上传到一个servlet，以便使用FormPanel进行解析，但是我没有从servlet得到任何响应

客户端代码我从onSubmit（）中看到窗口，但onSubmitComplete没有响应

web.xml relvant web.xml代码


上传的CSVParser
ca.ubc.cs310.gwt.healthybc.server.UploadedCSVParser
上传的CSVParser
/healthybc/uploadServlet

服务器代码

公共类UploadedCSVParser扩展HttpServlet{
@凌驾
受保护的void doGet（HttpServletRequest请求，HttpServletResponse响应）抛出ServletException，IOException
{
doPost（请求、响应）；
}
@凌驾
受保护的void doPost（HttpServletRequest请求、HttpServletResponse响应）引发ServletException、IOException
{
response.setContentType（“text/html”）；
PrintWriter out=response.getWriter（）；
out.println（“”）；
out.println（“”）；
out.println（“servlet标题”）；
out.println（“”）；
out.println（“”）；
out.println（“”）；
out.println（“文本在此显示”）；
out.println（“”）；
out.close（）；
}

现在服务器代码就在那里，看我是否真的得到了响应。在我的浏览器中直接输入URL…/healthybc/uploadServlet（我使用的是firefox）会给我预期的“文本在此显示”输出，但我没有收到任何迹象表明提交表单时onSubmitComplete曾经运行过。我开始认为信息永远不会到达servlet

我做错什么了吗？有没有什么简单的方法可以检查servlet是否真的被调用了？

我不知怎么地修复了它。我从一个已知的工作模板中重新定义了客户端，我认为它的顺序可能与我最初使用的略有不同

    final FormPanel form = new FormPanel();
    form.setMethod(FormPanel.METHOD_POST);
    form.setEncoding(FormPanel.ENCODING_MULTIPART);
    form.setAction("/healthybc/uploadServlet");

        // then there's a button they can click which calls form.submit();
    form.setWidget(new Button("Submit", (new ClickHandler() {
      @Override
      public void onClick(ClickEvent event) {
        form.submit();
      }
    })));

    buttonPanel.add(form);

    final FileUpload fileUpload = new FileUpload();
    fileUpload.setName("Browse");
    buttonPanel.add(clinicFileUpload);

    // Add an event handler to the form.
    form.addSubmitHandler(new FormPanel.SubmitHandler() {
        public void onSubmit(SubmitEvent event) {
            // This event is fired just before the form is submitted. We can take
            // this opportunity to perform validation.

            if (fileUpload.getFilename().length() == 0) {
                Window.alert("The text box must not be empty");
                event.cancel();
            }
            else if (!fileUpload.getFilename().endsWith(".csv")){
                Window.alert("Can only upload .csv files");
                event.cancel();
            }

        }
    });

    form.addSubmitCompleteHandler(new FormPanel.SubmitCompleteHandler() {
        @Override
        public void onSubmitComplete(SubmitCompleteEvent event) {
          // When the form submission is successfully completed, this event is
          // fired. Assuming the service returned a response of type text/html,
          // we can get the result text here (see the FormPanel documentation for
          // further explanation).
          Window.alert(event.getResults());
        }
      });

public class UploadedCSVParser extends HttpServlet{   
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
{
    doPost(request, response);
}

@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
{
    response.setContentType("text/html");
    PrintWriter out = response.getWriter();


    out.println("<html>");
             out.println("<head>");
             out.println("<title> servlet title</title>");
             out.println("</head>");
              out.println("<body>");
              out.println("</body>");

         out.println("TEXT GOES HERE");

                out.println("</html>");
                out.close();


}

    final FormPanel form = new FormPanel();
    form.setMethod(FormPanel.METHOD_POST);
    form.setEncoding(FormPanel.ENCODING_MULTIPART);
    form.setAction("/healthybc/uploadServlet");

        // then there's a button they can click which calls form.submit();
    form.setWidget(new Button("Submit", (new ClickHandler() {
      @Override
      public void onClick(ClickEvent event) {
        form.submit();
      }
    })));

    buttonPanel.add(form);

    final FileUpload fileUpload = new FileUpload();
    fileUpload.setName("Browse");
    buttonPanel.add(clinicFileUpload);

    // Add an event handler to the form.
    form.addSubmitHandler(new FormPanel.SubmitHandler() {
        public void onSubmit(SubmitEvent event) {
            // This event is fired just before the form is submitted. We can take
            // this opportunity to perform validation.

            if (fileUpload.getFilename().length() == 0) {
                Window.alert("The text box must not be empty");
                event.cancel();
            }
            else if (!fileUpload.getFilename().endsWith(".csv")){
                Window.alert("Can only upload .csv files");
                event.cancel();
            }

        }
    });

    form.addSubmitCompleteHandler(new FormPanel.SubmitCompleteHandler() {
        @Override
        public void onSubmitComplete(SubmitCompleteEvent event) {
          // When the form submission is successfully completed, this event is
          // fired. Assuming the service returned a response of type text/html,
          // we can get the result text here (see the FormPanel documentation for
          // further explanation).
          Window.alert(event.getResults());
        }
      });