file.java

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  public long length ()
  {
    checkRead();
    return attr (LENGTH);
  }
    
  private final native Object[] performList (FilenameFilter filter,
					     FileFilter fileFilter,
					     Class result_type);

  public String[] list (FilenameFilter filter)
  {
    checkRead();
    return (String[]) performList (filter, null, String.class);
  }

  public String[] list ()
  {
    checkRead();
    return (String[]) performList (null, null, String.class);
  }

  /** @since 1.2 */
  public File[] listFiles()
  {
    checkRead();
    return (File[]) performList (null, null, File.class);
  }
  
  /** @since 1.2 */
  public File[] listFiles(FilenameFilter filter)
  {
    checkRead();
    return (File[]) performList (filter, null, File.class);
  }
  
  /** @since 1.2 */
  public File[] listFiles(FileFilter filter)
  {
    checkRead();
    return (File[]) performList (null, filter, File.class);
  }

  public String toString ()
  {
    return path;
  }

  public URL toURL () throws MalformedURLException
  {
    // On Win32, Sun's JDK returns URLs of the form "file:/c:/foo/bar.txt",
    // while on UNIX, it returns URLs of the form "file:/foo/bar.txt". 
    if (separatorChar == '\\')
      return new URL ("file:/" + getAbsolutePath ().replace ('\\', '/')
		      + (isDirectory() ? "/" : ""));
    else
      return new URL ("file:" + getAbsolutePath ()
		      + (isDirectory() ? "/" : ""));
  }

  private final native boolean performMkdir ();

  public boolean mkdir ()
  {
    checkWrite();
    return performMkdir ();
  }

  private static boolean mkdirs (File x)
  {
    if (x.isDirectory())
      return true;
    String p = x.getPath();
    String parent = x.getParent();
    if (parent != null)
      {
	x.path = parent;
	if (! mkdirs (x))
	  return false;
	x.path = p;
      }
    return x.mkdir();
  }

  public boolean mkdirs ()
  {
    checkWrite();
    if (isDirectory ())
      return false;
    return mkdirs (new File (path));
  }

  private static synchronized String nextValue ()
  {
    return Long.toString(counter++, Character.MAX_RADIX);
  }

  /** @since 1.2 */
  public static File createTempFile (String prefix, String suffix,
				     File directory)
    throws IOException
  {
    // Grab the system temp directory if necessary
    if (directory == null)
      {
	String dirname = tmpdir;
	if (dirname == null)
	  throw 
	    new IOException("Cannot determine system temporary directory"); 
	
	directory = new File(dirname);
	if (!directory.exists())
	  throw new IOException("System temporary directory " 
				+ directory.getName() + " does not exist.");
	if (!directory.isDirectory())
	  throw new IOException("System temporary directory " 
				+ directory.getName() 
				+ " is not really a directory.");
      }

    if (prefix.length () < 3)
      throw new IllegalArgumentException ("Prefix too short: " + prefix);
    if (suffix == null)
      suffix = ".tmp";

    // Truncation rules.
    // `6' is the number of characters we generate.
    if (prefix.length () + 6 + suffix.length () > maxPathLen)
      {
	int suf_len = 0;
	if (suffix.charAt(0) == '.')
	  suf_len = 4;
	suffix = suffix.substring(0, suf_len);
	if (prefix.length () + 6 + suf_len > maxPathLen)
	  prefix = prefix.substring(0, maxPathLen - 6 - suf_len);
      }

    File f;

    // How many times should we try?  We choose 100.
    for (int i = 0; i < 100; ++i)
      {
	// This is ugly.
	String t = "ZZZZZZ" + nextValue ();
	String l = prefix + t.substring(t.length() - 6) + suffix;
	try
	  {
	    f = new File(directory, l);
	    if (f.createNewFile())
	      return f;
	  }
	catch (IOException ignored)
	  {
	  }
      }

    throw new IOException ("cannot create temporary file");
  }

  private native boolean performSetReadOnly();

  /** @since 1.2 */
  public boolean setReadOnly()
  {
    checkWrite();
    return performSetReadOnly();
  }

  private static native File[] performListRoots();

  /** @since 1.2 */
  public static File[] listRoots()
  {
    File[] roots = performListRoots();
    
    SecurityManager s = System.getSecurityManager();
    if (s != null)
      {
	// Only return roots to which the security manager permits read access.
	int count = roots.length;
	for (int i = 0; i < roots.length; i++)
	  {
	    try
	      {
        	s.checkRead(roots[i].path);		
	      }
	    catch (SecurityException sx)
	      {
	        roots[i] = null;
		count--;
	      }
	  }
	if (count != roots.length)
	  {
	    File[] newRoots = new File[count];
	    int k = 0;
	    for (int i=0; i < roots.length; i++)
	      {
	        if (roots[i] != null)
		  newRoots[k++] = roots[i];
	      }
	    roots = newRoots;
	  }
      }
    return roots;
  }

  public static File createTempFile (String prefix, String suffix)
    throws IOException
  {
    return createTempFile (prefix, suffix, null);
  }

  /** @since 1.2 */
  public int compareTo(File other)
  {
    if (caseSensitive)
      return path.compareTo (other.path);
    else
      return path.compareToIgnoreCase (other.path);
  }

  /** @since 1.2 */
  public int compareTo(Object o)
  {
    File other = (File) o;
    return compareTo (other);
  }

  private native boolean performRenameTo (File dest);
  public boolean renameTo (File dest)
  {
    SecurityManager s = System.getSecurityManager();
    String sname = getName();
    String dname = dest.getName();
    if (s != null)
      {
	s.checkWrite(sname);
	s.checkWrite(dname);
      }
    return performRenameTo (dest);
  }

  private native boolean performSetLastModified(long time);
  
  /** @since 1.2 */
  public boolean setLastModified(long time)
  {
    checkWrite();
    return performSetLastModified(time);
  }

  public static final String pathSeparator
    = System.getProperty("path.separator");
  public static final char pathSeparatorChar = pathSeparator.charAt(0);
  public static final String separator = System.getProperty("file.separator");
  public static final char separatorChar = separator.charAt(0);

  static final String tmpdir = System.getProperty("java.io.tmpdir");
  static int maxPathLen;
  static boolean caseSensitive;
  static String dupSeparator = separator + separator;
  
  static
  {
    init_native();
  }
  
  // Native function called at class initialization. This should should
  // set the maxPathLen and caseSensitive variables.
  private static native void init_native();

  // The path.
  private String path;

  // We keep a counter for use by createTempFile.  We choose the first
  // value randomly to try to avoid clashes with other VMs.
  private static long counter = Double.doubleToLongBits (Math.random ());

  private void checkWrite ()
  {
    SecurityManager s = System.getSecurityManager();
    if (s != null)
      s.checkWrite(path);
  }

  private void checkRead ()
  {
    SecurityManager s = System.getSecurityManager();
    if (s != null)
      s.checkRead(path);
  }

  /** 
    * Add this File to the set of files to be deleted upon normal
    * termination.
    *
    * @since 1.2 
    */
  // FIXME: This should use the ShutdownHook API once we implement that.
  public void deleteOnExit ()
  {
    SecurityManager sm = System.getSecurityManager ();
    if (sm != null)
      sm.checkDelete (getName ());

    FileDeleter.add (this);
  }

  private void writeObject (ObjectOutputStream oos) throws IOException
  {
    oos.defaultWriteObject ();
    oos.writeChar (separatorChar);
  }

  private void readObject (ObjectInputStream ois)
    throws ClassNotFoundException, IOException
  {
    ois.defaultReadObject ();

    // If the file was from an OS with a different dir separator,
    // fixup the path to use the separator on this OS.
    char oldSeparatorChar = ois.readChar ();
    if (oldSeparatorChar != separatorChar)
      path = path.replace (oldSeparatorChar, separatorChar);
  }

  // QUERY arguments to access function.
  private final static int READ = 0;
  private final static int WRITE = 1;
  private final static int EXISTS = 2;

  // QUERY arguments to stat function.
  private final static int DIRECTORY = 0;
  private final static int ISFILE = 1;
  private final static int ISHIDDEN = 2;

  // QUERY arguments to attr function.
  private final static int MODIFIED = 0;
  private final static int LENGTH = 1;
  
  private final native long attr (int query);
  // On OSF1 V5.0, `stat' is a macro.  It is easiest to use the name
  // `_stat' instead.  We do the same thing for `_access' just in
  // case.
  private final native boolean _access (int query);
  private final native boolean _stat (int query);

  private static final long serialVersionUID = 301077366599181567L;
}