protected void unpackComponents() throws IOException, FileNotFoundException {
    File applicationPackage = new File(getApplication().getPackageResourcePath());
    File componentsDir = new File(sGREDir, "components");
    if (componentsDir.lastModified() == applicationPackage.lastModified()) return;

    componentsDir.mkdir();
    componentsDir.setLastModified(applicationPackage.lastModified());

    GeckoAppShell.killAnyZombies();

    ZipFile zip = new ZipFile(applicationPackage);

    byte[] buf = new byte[32768];
    try {
      if (unpackFile(zip, buf, null, "removed-files")) removeFiles();
    } catch (Exception ex) {
      // This file may not be there, so just log any errors and move on
      Log.w(LOG_FILE_NAME, "error removing files", ex);
    }

    // copy any .xpi file into an extensions/ directory
    Enumeration<? extends ZipEntry> zipEntries = zip.entries();
    while (zipEntries.hasMoreElements()) {
      ZipEntry entry = zipEntries.nextElement();
      if (entry.getName().startsWith("extensions/") && entry.getName().endsWith(".xpi")) {
        Log.i("GeckoAppJava", "installing extension : " + entry.getName());
        unpackFile(zip, buf, entry, entry.getName());
      }
    }
  }
  /**
   * Constructor
   *
   * @throws IOException
   */
  public JustAnotherPackageManager(Reporter reporter, Platform platform, File homeDir, File binDir)
      throws IOException {
    this.platform = platform;
    this.reporter = reporter;
    this.homeDir = homeDir;
    if (!homeDir.exists() && !homeDir.mkdirs())
      throw new IllegalArgumentException("Could not create directory " + homeDir);

    repoDir = IO.getFile(homeDir, "repo");
    if (!repoDir.exists() && !repoDir.mkdirs())
      throw new IllegalArgumentException("Could not create directory " + repoDir);

    commandDir = new File(homeDir, COMMANDS);
    serviceDir = new File(homeDir, SERVICE);
    commandDir.mkdir();
    serviceDir.mkdir();
    service = new File(repoDir, SERVICE_JAR_FILE);
    if (!service.isFile()) init();

    this.binDir = binDir;
    if (!binDir.exists() && !binDir.mkdirs())
      throw new IllegalArgumentException("Could not create bin directory " + binDir);
  }