Re: Error updating code to 1.5

From:

"Daniel Pitts" <googlegroupie@coloraura.com>

Newsgroups:

comp.lang.java.programmer

Date:

24 Nov 2006 10:25:34 -0800

Message-ID:

<1164392734.216652.158710@h54g2000cwb.googlegroups.com>

inanetheory@gmail.com wrote:

I just need some help figuring out how to solve this, cause I'm stuck.

Error: java.lang.Comparable cannot be inherited with different
arguments: <> and <java.io.File>

<------------ Code ------------>

import java.util.*;
import java.io.File;
import java.text.Collator;

import javax.swing.tree.TreeModel;
import javax.swing.tree.TreePath;
import javax.swing.event.TreeModelListener;
import javax.swing.event.TreeModelEvent;
  private class FileTreeNode extends File implements Comparable
  {
    public FileTreeNode(File file)
    {
      super(file, "");
    }

    /**
     * Compare two FileTreeNode objects so that directories
     * are sorted first.
     *
     * @param object Object to compare to.
     * @return Compare identifier.
     */
    public int compareTo (Object object)
    {
      File file1 = this;
      File file2 = (File) object;

      Collator collator = Collator.getInstance();

      if (file1.isDirectory() && file2.isFile())
        return -1;
      else if (file1.isFile() && file2.isDirectory())
        return +1;
      else
        return collator.compare(file1.getName(), file2.getName());
    }

My first suggestion is that you change your FileTreeNode from "is a
File" to "Has a File". And make it comparable to its own type.

  private class FileTreeNode implements Comparable<FileTreeNode> {
     private final File file;
     public FileTreeNode(File file) {
       this.file = file;
     }

     /**
      * Compare two FileTreeNode objects so that directories
      * are sorted first.
      *
      * @param object Object to compare to.
      * @return Compare identifier.
      */
     public int compareTo (FileTreeNode object) {
       final File file1 = this.file;
       final File file2 = object.file;

       Collator collator = Collator.getInstance();

       if (file1.isDirectory() && file2.isFile())
         return -1;
       else if (file1.isFile() && file2.isDirectory())
         return +1;
       else
         return collator.compare(file1.getName(), file2.getName());
     }
  }

Hope this helps.
Daniel.