CODEWITHSUNDEEP
javaexceptioniterator
Jason Renaldo
Jason Renaldo

Reputation: 2822

Why NoSuchElement Exception is being thrown, when I am checking if there is an element beforehand?

I have a JSP page where the user can select multiple check boxes (there are up to 10). Sometimes, if multiple check boxes are checked, NoSuchElement exception is thrown.

Servlet Code:

 Iterator<ClassInfo> iterateCurrentResultSet = resultSet.iterator();

        //If the current class's location isn't contained in "locations", the user didn't select it so remove
        //It from the results.
        while(iterateCurrentResultSet.hasNext())
        {
            //Evaluate every location they checked for, remove any class that isn't one of these locations.
            for(String selectedLocation : locations)
            {
                //IF THE EXCEPTION OCCURS, IT DOES HERE. Current class location, it this doesn't match the user's selected criteria, it's removed.
                String currentClassLocation = iterateCurrentResultSet.next().getSectionLocation();

                //Check if the user wants to see other classes, if not, continue on.
                if(selectedLocation.equals("OTH"))
                {
                    //If this is false, keep it because it is an "Other" class, such as SFD, CWD, etc.
                    if(mainCampusCode.contains(currentClassLocation))
                    {
                        iterateCurrentResultSet.remove();
                    }//doNothing();
                }
                else
                {
                    //If it does not have one of the selected locations, remove it.
                    if(!currentClassLocation.contains(selectedLocation))
                    {
                        iterateCurrentResultSet.remove();
                    }//doNothing();
                }

            }
        }

I have not sure why it is throw, as I understood from the JavaDoc, it seems like happens if there is no element, but I thought iterateCurrentResultSet.hasNext() ensure that I was dealing with an element.

Upvotes: 0

Views: 93

Answers (1)

MrSmith42
MrSmith42

Reputation: 10151

You check for iterateCurrentResultSet.hasNext() in the outer loop, but if there is more than one locations you call next() more than once in the for-loop.

I would replace 

String currentClassLocation = iterateCurrentResultSet.next().getSectionLocation();

by

if(!iterateCurrentResultSet.hasNext())
  break; // exit for-loop if there is no next
String currentClassLocation = iterateCurrentResultSet.next().getSectionLocation();

Upvotes: 4

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