UPDATE: After browsing through the reference i finally found out that it's not possible to compare strings using the equality operator. The reference for the '==' operator states that it is possible tough...


Hi everyone. I'm terribly stuck with the sketch below. I'm trying to accomplish the following:

-Load Last.FM Chart data
-Create an ArtistPool object that gets filled with Artist objects as i parse the XML files, leaving me with a workable data structure (without doubled artists) when i'm done parsing.

I'm stuck with the getIndexInPool() function. It keeps returning -1 because the if statement in the functions fails to work

-> if (aname == testName) {

for some reason it is unable to compare the string that was passed to the function with the _artists[i].name string, yet when i compare the strings manually (by cutting and pasting the values from the xml) it works. I've tried casting values to strings, stepping thru it  manually, bassicly anything i could think of, but i'm still stuck.

Some help would be appreciated! :)




Code:

import processing.xml.*;

String chartlistFilename = "weeklychartlist.xml";
String weeklyArtistChartListFilename = "weeklyartistchart";

XMLElement xml;
ArtistPool pool;
Artist artist;

class Artist {
  
  String name;
  int[] chartPosition;
  int[] playCount; 
  
  Artist(String Aname, int weeks) {
    // var setup
    name = Aname;
    chartPosition = new int[weeks];
    playCount = new int[weeks];
    //
    // prefilling the artist positions with empty values.
    //
    for (int i = 0; i<weeks; i++) {
      chartPosition[i] = 0;
      playCount[i] = 0;
    }
  }
  
  void updateArtist(int week,int chartPos,int playCnt) {
    chartPosition[week] = chartPos;
    playCount[week] = playCnt;
  }
  String artistName() {
    return name;
  }
  
}

class ArtistPool {
  
    Artist[] _artists;
  
  ArtistPool () {
    _artists = new Artist[0];
  }
  
  int getIndexInPool (String aname) {
    int index = -1;
    
    
    
    for (int i = 0; i< _artists.length;i++) {
      String testName = _artists[i].name;
      //println(aname+':'+testName);
      if (aname == testName) {
          index = i;
          println("if werkt");
        }
       
    }
   
    return index;
  }
  void updatePool (Artist artist, int artistIndex) {
    _artists[artistIndex] = artist;
    print("update");
    
  }
  
  void insertIntoPool (Artist artist) {
    _artists = (Artist[]) append(_artists, artist);
    
  }
  
  Artist getArtistFromPool(int index) {
    return _artists[index];
  }
  
  int poolSize() {
    return _artists.length;
  }
}

void setup () {

  size (200,200);
  xml = new XMLElement (this, chartlistFilename);
  int numElements = xml.getChildCount();
  pool = new ArtistPool();
 
 String[] fileNames = new String[numElements];
 
  for (int i = 0; i<numElements; i++) {

    XMLElement chart = xml.getChild(i);   
    String from = chart.getStringAttribute("from");
    String to = chart.getStringAttribute("to");
    String fileName = from + "-" + to + "-" + weeklyArtistChartListFilename + ".xml";
    fileNames[i] = fileName;   
  }
  
  for (int i = 0; i<fileNames.length; i++) {
  
    xml = new XMLElement (this, fileNames[i]);
    int numElements2 = xml.getChildCount();
    for (int j = 0; j<numElements2; j++) {
  
      XMLElement artistElement = xml.getChild(j);
      XMLElement artistName = artistElement.getChild(0);
      XMLElement chartPosition = artistElement.getChild(2);
      XMLElement playCount = artistElement.getChild(3);
      
      String aName = artistName.getContent();
      int pCount = int(playCount.getContent());
      int chartPos = int(chartPosition.getContent());
      
      int currentArtistIndex = pool.getIndexInPool(aName);
      //print (currentArtistIndex);
      if (currentArtistIndex != -1) {
        
        Artist currentArtist = pool.getArtistFromPool(currentArtistIndex);
        currentArtist.updateArtist(i,chartPos,pCount);
        pool.updatePool(currentArtist,currentArtistIndex);
        
      } else {
        artist = new Artist(aName,numElements);
        artist.updateArtist(i,chartPos,pCount);
        pool.insertIntoPool(artist); 
      }   
    }
  }
  String a = pool._artists[0].name;
  String b = pool._artists[5].name;
  
  println(a);
  println(b);
  
  if(a == b) {
    println("This if just won't work");
  }
}