[FIXED] AppEngine/Java: delete items retrieved from checkboxes

Issue

Here my problem: I have a .jsp file with the following code:

form class="form" action="deleteServlet" method="post">      
  <%
  DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();
  Query query = new Query("Notice").addSort("date", Query.SortDirection.DESCENDING);
  PreparedQuery pq = datastore.prepare(query);
  for (Entity notice : pq.asIterable()) {
    String title = (String) notice.getProperty("title");
  %>
  <input type="checkbox" name="selected" 
         value=" <% KeyFactory.keyToString(notice.getKey()); %> " >     
  <%out.println(title);
  } %> 
  <input type="submit" value="Delete!">
</form>     

I do a query on AppEngine datastore to get a list of items. I need to show each of this item with a checkbox, in a way that user can select some of them and delete them from datastore. Logic is managed using a Servlet, in this way:

public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {

     DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();
     String[] noticesChecked = req.getParameterValues("selected");

     for (int i=0; i<noticesChecked.length; i++) {
         Key noticeKey = KeyFactory.stringToKey(noticesChecked[i]);
         datastore.delete(noticeKey);
     }

I get, using getParameterValues, an array of selected items. Then, I iterate on them and I try to delete them from datastore. Since I cannot pass to a servlet a Key object, I use KeyFactory.keyToString and KeyFactory.stringToKey to convert to a String and pass it.

My problem is that elements in noticesChecked are all empty String "". I checked and notice.getKey gives me correct key. Also keyToString and stringToKey seem to work well. A check on array size tell me that isn't null, but it's correctly related to items checked. However all elements in this array are "".

Someone with a similar problem? Any idea about the problem? Where is the mistake?

Thanks in advance.

Solution

Try replacing this part of the jsp code:

<% KeyFactory.keyToString(notice.getKey()); %>

by this one:

<%= KeyFactory.keyToString(notice.getKey()) %>

since you want to insert the value of the expression.

Answered By - David Levesque