Need Help With Iteration Problem

Question

So I recently decided I would try and make a program to help me edit my mp3 ID3 tags. I'm relatively new to Java but can usualy figure things out on my own. My code is rarely efficient but it gets the job done. So here's the deal. I got this package from ID3.org and started messing around with it. I can get it to edit the tags but not with an iteration. Here's my code:
import javax.swing.*;
import de.vdheide.mp3.*;
import java.io.*;
class ID3TagEdit {
     public static void main(String args[]) {
          String dir = chooseDir();
          String[] fileList = makeList(dir);
          String filename = "";
          for(int i = 0; fileList[i] != "null"; i++) {
               try {
                    filename = dir + "\\" + fileList;
                    MP3File currentFile = new MP3File(filename);
                    TagContent tc = currentFile.getArtist();
                    tc.setContent("TEST");
                    currentFile.setArtist(tc);
                    currentFile.update();
               catch(IOException e) {
                    System.out.println("Error 101");
               catch(FrameDamagedException e) {
                    System.out.println("Error 102");
               catch(NoMP3FrameException e) {
                    System.out.println("Error 103");
               catch(TagFormatException e) {
                    System.out.println("Error 104");
               catch(ID3Exception e) {
                    System.out.println("Error 105");
               catch(ID3v2WrongCRCException e) {
                    System.out.println("Error 106");
               catch(ID3v2Exception e) {
                    System.out.println("Error 107");
     public static String chooseDir() {
          String FolderPath = "";
          try {
               JFileChooser chooser = new JFileChooser();
               chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
               int returnVal = chooser.showOpenDialog(null);
               FolderPath = chooser.getSelectedFile().getPath();
          catch(IllegalArgumentException e) {
               System.out.println("Error 201");
          return FolderPath;
     public static String[] makeList(String dir) {
          File directory = new File(dir);
          String[] fileList = directory.list();
          return fileList;
If I don't iterate it then it will work. If I omit the 'for' loop and change the code to this:
                    filename = dir + "\\" + fileList[3];
                    MP3File currentFile = new MP3File(filename);
                    TagContent tc = currentFile.getArtist();
                    tc.setContent("TEST");
                    currentFile.setArtist(tc);
                    currentFile.update();
It works just fine. Any suggestions on what I'm doing wrong?

Answer 1

If I don't iterate it then it will work. If I omit
the 'for' loop and change the code to this:
It works just fine. Any suggestions on what I'm
doing wrong?You said
without loop it works just fine.Then what's the wrong?
If you don't use loop then your fileList may not be null.And then your program'll be in infinite loop.