Re: simple java help

From:
Trung Chinh Nguyen <chinhnt2k3@gmail.com>
Newsgroups:
comp.lang.java.programmer
Date:
Thu, 27 Apr 2006 14:22:44 GMT
Message-ID:
<Us44g.949$EM5.612@newsfe3-win.ntli.net>
You forgot to call the constructor list[len] = new ResourceList();

laclac01@gmail.com wrote:

I have attached code and was wondering if someone can help me though
it. I am just trying to make a simple database type program so i can
learn java. I know C++ well so i think i still need to get out of the
c++ mindset.
I get this error in eclipse "Exception in thread "main"
java.lang.NullPointerException
    at allLists.AddName(allLists.java:12)
    at server.main(server.java:20)"
I havent a clue what it means But i get the error when doing the
command
list[len].name = name;
in my addName method.
Why can't just do this and it work?

public static void main(String[] args)
    {

        ServerSocket s = null;
        allLists list = new allLists();
        list.AddName("jack","was","here");
        try
        {
            s = new ServerSocket(SERVERPORT);
        }
        catch(IOException e)
        {
            System.out.println(e);
            System.exit(1);
        }

        //while (true)
        //{
            Socket incoming = null;
            try
            {
             incoming = s.accept();
            }
            catch(IOException e)
            {
             System.out.println(e);
          // continue;
            }

            new inSocket(incoming, list).start();

        //}

    }

}

public class allLists
{
    ResourceList[] list = new ResourceList[1000];
    int len=0;

    void AddName(String name, String IP, String reliability)
    {
        System.out.println(name);
        System.out.println(len);
        list[len].name = name;
        len++;

    }
    void PrintName()
    {
        System.out.println(list[0].name);
    }

public class ResourceList
{
    public String name;
    public String IP;
    public String Reliability;

}

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