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Thread: From List<String> to a generic LinkedList

  1. #1
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    Default From List<String> to a generic LinkedList

    Hi guys,

    I was hoping someone can help me. I've been stuck on a problem for some time and I can't seem to find the solution.

    My task is to take elements from a List<string> and put them into a generic linked list.

    I've figured out how to use the listIterator and used that to cycle through all the names.

    It works as long as I put in System.out.println(x); to the screen.

    When I try to place the values into the LinkedList I get a never ending NullPointerException.

    Here's the code if it helps:

    //from main in a main source
    List<String> words3 = Collections.unmodifiableList(names2);
    aLinkedList wordlist = new LinkedList(names3);
    System.out.println();

    //from the linkedlist source
    public aLinkedList(List<String> words){
    ListIterator<String> itr = words.listIterator();

    while (itr.hasNext()) {
    String name = itr.next();
    // System.out.println(words);
    LLWords.add(words);
    // for(String word : words) {
    // System.out.println(words);
    // }
    }

    I was trying different things and that's what the //'s were for. Thanks for any help.

    -J


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: From List<String> to a generic LinkedList

    I get a never ending NullPointerException.
    Please copy and paste enough of the error message to identify what line it occurs on.
    Look at that line of code and see which variable is null. Then back track to see why that variable is null.

  3. #3
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    Default Re: From List<String> to a generic LinkedList

    I just resolved my own issue. The admin can delete my original post because it's not going to be helpful as it is now.

    Thanks anyway.

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