servlets - Cannot read form values from JSP -

I have a JSP page, which is full of tables form when I click submit it on the servlet Which is used to read the values ​​of the forms in the survey using the getParamValues ​​method but it is not working. When I try to print string array from GetParamValues, I get nullpointerexceptions

Here is the relevant servlet code:

  Public Zero doPost (httpPrelevate Request ), IOException throws, ServletException {resp.setContentType ("text / plain"); PrintWriter out = resp.getWriter (); String [] nums = req.getParameterValues ​​("questNum"); Out.println (nums [2]); } Secure zero doGet (HttpServletRequest request, HttpServletResponse resp) throws IOException, ServletException {doPost (req, resp); }   
 Here is the relevant JSP code, running on GAE:  
   & Lt;% @ Page Import = "com.surveycreator.service.preistence.SurveyPersistence"%> & Lt;% @ Page Import = "com.surveycreator.service.model.Sarvey"%> & Lt;% @ Page Import = "com.surveycreator.service.model.SurveyQuestion"%> & Lt;% @ Page Import = "com.surveycreator.service.model.Sarvey"%> & Lt;% @ Page Import = "java.util.list"% & gt; & Lt; Html & gt; & Lt; Top & gt; & Lt; Link type = "text / css" rel = "stylesheet" href = "/ stylesheets / main.css" /> & Lt; / Head & gt; & Lt; Body & gt; & Lt; P & gt; View survey & lt; / P & gt; & Lt; Form action = "/ storeserver" method = "post" & gt; & Lt; Input type = "submit" value = "submit survey" /> & Lt; / Form & gt; & Lt;% SurveyPersistence continues = new survey (); String survey name = request.getParameter ("content"); Survey survey = persist.getserve (survey name); & Lt; SurveyQuestion & gt; Question = Survey.GatesServe (); Out.println ("& lt; Table border = '1' & gt; & lt; tr & gt; & lt; th & gt; Question number & lt; / th> & lt; th & gt; Surveys question   (Yes / Yes)) & lt; / or & gt; & lt; / tr & gt; "); (Survey Question Question: Object: Question) {int tableCounterString = questionObject.getQuestionNumber (); String search = Question object. Grah Query (); Out.println ("& lt; tr>  
     gt; & lt ; Input id = 'question' name = 'search' type = 'text' to read only = 'read' value = '"+ search +"' / / gt;   & lt; td & gt; & lt; form & gt; & lt; input id = 'ans' name = 'answer' type = 'text' value = '' / / gt; & lt; / form & Gt; & lt; / TD & gt; & lt; / tr & gt; "); }% & Gt; & Lt;% = survey.getSurveyName ()%> & Lt; / Body & gt; & Lt; / Html & gt; Based on the information given so far, the only possible cause of NPE is that    
 
 any   ,   gt; Or  & lt; Textarea & gt;  element not according to JSP code  
 
  Update : With a  name = "questNum"  anywhere in the HTML form . The submit button is actually input field from an  different  HTML field, as input field, you must put the submit button in the  same  HTML form depending on the functional requirement - which Time is not ambiguous - you need to move the submission cell to the table cell, or   & lt; Form & gt; .            Poor practice. If you ever open your server by entering your URL in the browser address bar, then do not leave any parameters, then you will  definitely  get the NPE. Do not do the same request to  doGet ()  for  preprocess  requests and  doPost ()  only  postprocess  Use the requests. As an example, JSP  scriptlet   & lt; %% & gt; All Java code inside  should be done in  doGet ()  method and HTML code by JSTL  and lt; C: forEach & gt;  should be repeated by tag.    

 


  















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