Problem with reading MP3 tag information

Question

This may be a simple fix, but I'm having no luck figuring it out. I've got an application here that scans through a given directory for all files. We are going to assume that all files below the given parent directory are *.mp3 files. Every file we find is going to have its path stored into an ArrayList. After the ArrayList is created, we will then through the ArrayList, getting the String value which is a path to our MP3 file.
The application works well when I am simply printing out the ArrayList to the console. It's printing out everything in the ArrayList. The ArrayList consists of both directories and paths to actual files. The problem comes when I am trying to take the String from the ArrayList, pass it into my getID() method. Here is the code. i've commented the line in my main method that is giving me problems.
* Main.java
* @author tristan
* Created on August 7, 2007, 4:26 PM
package audioidreader;
import java.io.*;
import java.util.*;
import org.blinkenlights.jid3.*;
import org.blinkenlights.jid3.v1.*;
import org.blinkenlights.jid3.v2.*;
public class Main
    /** Creates a new instance of Main */
    public Main ()
     * @param args the command line arguments
    public static void main (String[] args) throws Exception
        /* tempDir is the directory where we will be searching for files. The ArrayList 'files'
         * is where all the file listings will be stored by using getFileListing(tempDir). The
         * for() loop get the size of the ArrayList, starts from the first index, and gets the
         * index value. The index values are supposed to be paths to an MP3 file. We will use
         * System.out.println() to print out all the paths to all the MP3s found to the console.
        File tempDir = new File ("/home/tristan/My Music");
        ArrayList files = (ArrayList) getFileListing ( tempDir );
        for(int i = 0; i < files.size (); i++)
            System.out.println ( files.get (i) );
            // getID((String) files.get (i)); // throws an exception
    static public ArrayList getFileListing ( File aStartingDir ) throws FileNotFoundException
        /* First, we check to see if our directory for the MP3s exists or not. In this case,
         * we are calling validateDirectory() with a file object passed from our main method.
         * If the directory is good, we then create a new Arraylist to store the results in.
         * We then scan through our directory and find every file within our parent directory
         * and we add the result, even directories, to the ArrayList. Once everything is done,
         * we return the 'result' ArrayList to where it was originally called from Main.
        validateDirectory (aStartingDir);
        ArrayList result = new ArrayList ();
        File[] filesAndDirs = aStartingDir.listFiles ();
        List filesDirs = Arrays.asList (filesAndDirs);
        Iterator filesIter = filesDirs.iterator ();
        File file = null;
        while ( filesIter.hasNext () )
            file = (File)filesIter.next ();
            result.add (file);
            if (!file.isFile ())
                List deeperList = getFileListing (file);
                result.addAll (deeperList);
        Collections.sort (result);
        return result;
    static private void validateDirectory (File aDirectory) throws FileNotFoundException
        /* This method checks to see if our parent directory that we entered is an existing
         * directory. If the directory does not validate, we will throw an exception specific
         * to the reason of not being valid.
        if (aDirectory == null)
            throw new IllegalArgumentException ("Directory should not be null.");
        if (!aDirectory.exists ())
            throw new FileNotFoundException ("Directory does not exist: " + aDirectory);
        if (!aDirectory.isDirectory ())
            throw new IllegalArgumentException ("Is not a directory: " + aDirectory);
        if (!aDirectory.canRead ())
            throw new IllegalArgumentException ("Directory cannot be read: " + aDirectory);
    static private void getID (String mp3) throws ID3Exception
        /* getID() is called by the main method. What we are attempting to do here is
         * receive the String (path to MP3 file) that is passed to us and do a test on
         * it. First, we will use the String to our MP3 and make it a file object.
         * After creating the file object, we are then using that object to create
         * an MP3 object. Now, we will read the tages from the object to determine
         * if it is an ID3 v1.0 or ID3 v2.3.0 tag. Regardless of what it is, we want to
         * print out some information to the console in the format of 'Artist - Title'.
        File oSourceFile = new File (mp3);
        MediaFile oMediaFile = new MP3File (oSourceFile);
        ID3Tag[] aoID3Tag = oMediaFile.getTags ();
        for (int i=0; i < aoID3Tag.length; i++)
            if (aoID3Tag[i] instanceof ID3V1_0Tag)
                ID3V1_0Tag ID3_1 = (ID3V1_0Tag)aoID3Tag;
if (ID3_1.getTitle () != null && ID3_1.getArtist () != null)
System.out.println (ID3_1.getArtist () + " - " + ID3_1.getTitle ());
else if (aoID3Tag[i] instanceof ID3V2_3_0Tag)
ID3V2_3_0Tag ID3_2 = (ID3V2_3_0Tag)aoID3Tag[i];
if (ID3_2.getArtist () != null && ID3_2.getTitle () != null)
System.out.println (ID3_2.getArtist () + " - " + ID3_2.getTitle ());
If I type in an actual String that is a path to an MP3, such as:
getID("/home/tristan/My Music/Incubus - Drive.mp3"); Everything works fine. I've tried casting the value pulled from the ArrayList as a String and then passing it to the getID() method, but my exception I am getting is:
Exception in thread "main" java.lang.ClassCastException: java.io.File cannot be cast to java.lang.String
        at audioidreader.Main.main(Main.java:38)
Java Result: 1Line 38 is the line I have commented out. Any ideas?

Answer 1

You're right. That is a bit misleading. Anyway, I
decided to not cast (String) to it. It was a simple
fix just like I figured, but of course I figure it
out after I made the post.
getID (files.get (i).toString ());fixed my problem. Thank you.But not in the correct way. You should really use the canonical path or the absolute path.