Problem with writing out a text file

[jazzermonty]

Hello again folks

Here's my issue. I've written a simple program that takes a files content and stores them in a HashMap so that it removes duplicates. So far so good. Now I want to write out the contents of the HashMap to a text file, with a CRLF after each entry has been written. Here is my code:

public void writeFile()
      {
         String pathname = OUFileChooser.getFilename();
         File aFile = new File(pathname);
         ObjectOutputStream outStream = null;
         try
            {
			   FileWriter writer = new FileWriter(aFile);
            Iterator it = noDuplicates.iterator();
               while (it.hasNext())
               {
                  writer.append(it.next().toString());
				      writer.append('\n');
				      System.out.println(noDuplicates.toString());
               }
            }
         
            catch (Exception anException)
            {
               System.out.println("Error: " + anException);
            }
            finally
         {
          try
             {
                outStream.close();
             }
          catch (Exception anException)
             {
                System.out.println("Error: " + anException);
             }
          }
         }

What I get though is an empty file and a nullPointerException. Any ideas where I'm going wrong? This isn't a homework question, just a pet project of mine.

Thanks in advance.

[Fubarable]

What line throws the NPE? Can you show us not just the line number, but the actual line of code itself?

[jazzermonty]

Hi Fubarable

Sorry about this, quickly realised my mistake and fixed it. For other members here's my solution:

 public void writeFile()
      {
         String pathname = OUFileChooser.getFilename();
         File aFile = new File(pathname);
         //ObjectOutputStream outStream = null;
         FileWriter writer = null;
         try
            {
			   writer = new FileWriter(aFile);
            Iterator it = noDuplicates.iterator();
               while (it.hasNext())
               {
                  writer.append(it.next().toString());
				      writer.append('\n');
				      System.out.println(noDuplicates.toString());
               }
            }
         
            catch (Exception anException)
            {
               System.out.println("Error: " + anException);
            }
            finally
         {
          try
             {
                writer.close();
             }
          catch (Exception anException)
             {
                System.out.println("Error: " + anException);
             }
          }
         }

Thanks folks