Find strings in a list using startsWith?

Question

Hi I hope someone can help me with this problem. Before I start, my apologies as I am a student still trying to learn Java and have got to the murky ground of data structures.To help me better understand this I tried a sample program (which surprisingly was working fine til now ha). So I have a list of songs by various artists added to a tree which begins with the singers name. I want to be able to isolate songs by a particular artist but have tried loads of different ways of doing it to no avail. I tried creating a new list but couldn't add my songs to it. I then found the remove() method and thought why not just find what I want and remove the rest from the list I can always recreate my list again after. So I think I'm close with my code and that's it's maybe a casting issue??
String song = songTree.getElement(currentNode);
List<String> list = MyCollection.getSongs(song);
// List newList = new ArrayList();
String check = new String("Pearl Jam");
Iterator myIter = list.iterator();
while (myIter.hasNext()){
if (myIter.next().!startsWith(check)){
// newList.add();
else{
list.remove();
Edited by: jojololo on Nov 9, 2009 11:35 AM

Answer 1

jojololo wrote:
Before I start, my apologies as I am a student still trying to learn Java and have got to the murky ground of data structures.No need to apologize, as long as you are clear in your communication. Why would we be here except to help? (Well okay, to amuse ourselves...)
To help me better understand this I tried a sample program (which surprisingly was working fine til now ha). So I have a list of songs by various artists added to a tree which begins with the singers name. I want to be able to isolate songs by a particular artist but have tried loads of different ways of doing it to no avail. I tried creating a new list but couldn't add my songs to it. Why not? What happened when you tried? This is probably the right way and should definitely work, so let's isolate the problem there.
I then found the remove() method and thought why not just find what I want and remove the rest from the list I can always recreate my list again after.Nah that doesn't seem like a reasonable idea. Let's go back to creating a new collection to hold your isolated subset.
Post an SSCCE of your atte this stagempt at using a new list, and tell us where it goes wrong and what you expect it to do instead. Be sure to use the CODE button in the editor to format your code.
Sorry didn't really answer your questions very well with my post;
I've tried so much at this stage I don't even remember what went wrong. basically in the try I posted just now the startsWith method is not recognised. I'm aware that I'm trying to compare an object reference to a string but thought I had dealt with that with my casting? I think my subset would be saved here in the new collection but again I'm missing something in the comparisment. Oh sometimes I feel like packing in the java! We do far too much theory and nowhere near enough actual coding.
import java.util.*;
public class Test {
    public static void main(String[] args){
        List variousArtists = new ArrayList();
        // Some intentionally doubled to ensure only one gets put on the tree later           
        variousArtists.add("Pearl Jam - Even Flow");
        variousArtists.add("U2 - The End Of The World");
        variousArtists.add("The Smashing Pumpkins - Spaceboy");
        variousArtists.add("Pearl Jam - Alive");
        variousArtists.add("The Smashing Pumpkins - Quiet");
        variousArtists.add("Pearl Jam - Black");
        variousArtists.add("U2 - The End Of The World");
        variousArtists.add("Radiohead - Street Spirit");
        variousArtists.add("U2 - One");
        variousArtists.add("Radiohead - Street Spirit");
        variousArtists.add("Radiohead - Street Spirit");
        variousArtists.add("The Smashing Pumpkins - Mayonaise");
        variousArtists.add("U2 - Mysterious Ways");
        variousArtists.add("The Smashing Pumpkins - Hummer");
        variousArtists.add("Pearl Jam - Even Flow");
        variousArtists.add("The Smashing Pumpkins - Disarm");
        variousArtists.add("U2 - One");
        variousArtists.add("The Smashing Pumpkins - Quiet");
        variousArtists.add("The Smashing Pumpkins - Mayonaise");
        variousArtists.add("Pearl Jam - Black");
        variousArtists.add("The Smashing Pumpkins - Mayonaise");
        variousArtists.add("Pearl Jam - Even Flow");
        variousArtists.add("Radiohead - Street Spirit");
        variousArtists.add("U2 - The End Of The World");
        List newList = new ArrayList();
        String check = new String("Pearl Jam");
        String search;
        Iterator myIter = variousArtists.iterator();
              while (myIter.hasNext()){
     search = (String) myIter.next();
           if (myIter.next().startsWith(check)){
                 newList.add(myIter);
}