/* Copyright (C) 2003 Vladimir Roubtsov. All rights reserved. * * This program and the accompanying materials are made available under * the terms of the Common Public License v1.0 which accompanies this distribution, * and is available at http://www.eclipse.org/legal/cpl-v10.html * * $Id: Files.java,v 1.1.1.1.2.1 2004/07/09 01:28:37 vlad_r Exp $ */ package com.vladium.util; import java.io.BufferedReader; import java.io.File; import java.io.FileReader; import java.io.IOException; import java.util.ArrayList; import java.util.HashSet; import java.util.LinkedList; import java.util.List; import java.util.Set; import java.util.StringTokenizer; // ---------------------------------------------------------------------------- /** * @author Vlad Roubtsov, (C) 2003 */ public abstract class Files { // public: ................................................................ /** * No duplicate elimination. * * @param atfile */ public static String [] readFileList (final File atfile) throws IOException { if (atfile == null) throw new IllegalArgumentException ("null input: atfile"); List _result = null; BufferedReader in = null; try { in = new BufferedReader (new FileReader (atfile), 8 * 1024); // uses default encoding _result = new LinkedList (); for (String line; (line = in.readLine ()) != null; ) { line = line.trim (); if ((line.length () == 0) || (line.charAt (0) == '#')) continue; _result.add (line); } } finally { if (in != null) try { in.close (); } catch (Exception ignore) {} } if ((_result == null) || _result.isEmpty ()) return IConstants.EMPTY_STRING_ARRAY; else { final String [] result = new String [_result.size ()]; _result.toArray (result); return result; } } /** * Converts an array of path segments to an array of Files. The order * of files follows the original order of path segments, except "duplicate" * entries are removed. The definition of duplicates depends on 'canonical': * * * Note that duplicate removal in classpaths affects ClassLoader.getResources(). * The first mode above makes the most sense, however the last one is what * Sun's java.net.URLClassLoader appears to do. Hence the last mode might be * necessary for reproducing its behavior in Sun-compatible JVMs. */ public static File [] pathToFiles (final String [] path, final boolean canonical) { if (path == null) throw new IllegalArgumentException ("null input: path"); if (path.length == 0) return IConstants.EMPTY_FILE_ARRAY; final List /* Files */ _result = new ArrayList (path.length); final Set /* String */ pathnames = new HashSet (path.length); final String separators = ",".concat (File.pathSeparator); for (int i = 0; i < path.length; ++ i) { String segment = path [i]; if (segment == null) throw new IllegalArgumentException ("null input: path[" + i + "]"); final StringTokenizer tokenizer = new StringTokenizer (segment, separators); while (tokenizer.hasMoreTokens ()) { String pathname = tokenizer.nextToken (); if (canonical) pathname = canonicalizePathname (pathname); if (pathnames.add (pathname)) { _result.add (new File (pathname)); } } } final File [] result = new File [_result.size ()]; _result.toArray (result); return result; } /** * Converts 'pathname' into the canonical OS form. This wrapper function * will return the absolute form of 'pathname' if File.getCanonicalPath() fails. */ public static String canonicalizePathname (final String pathname) { if (pathname == null) throw new IllegalArgumentException ("null input: pathname"); try { return new File (pathname).getCanonicalPath (); } catch (Exception e) { return new File (pathname).getAbsolutePath (); } } public static File canonicalizeFile (final File file) { if (file == null) throw new IllegalArgumentException ("null input: file"); try { return file.getCanonicalFile (); } catch (Exception e) { return file.getAbsoluteFile (); } } /** * Invariant: (getFileName (file) + getFileExtension (file)).equals (file.getName ()). * * @param file File input file descriptor [must be non-null] * * @return String file name without the extension [excluding '.' separator] * [if 'file' does not appear to have an extension, the full name is returned]. * * @throws IllegalArgumentException if 'file' is null */ public static String getFileName (final File file) { if (file == null) throw new IllegalArgumentException ("null input: file"); final String name = file.getName (); int lastDot = name.lastIndexOf ('.'); if (lastDot < 0) return name; return name.substring (0, lastDot); } /** * Invariant: (getFileName (file) + getFileExtension (file)).equals (file.getName ()). * * @param file File input file descriptor [must be non-null] * * @return String extension [including '.' separator] or "" if 'file' does not * appear to have an extension. * * @throws IllegalArgumentException if 'file' is null */ public static String getFileExtension (final File file) { if (file == null) throw new IllegalArgumentException ("null input: file"); final String name = file.getName (); int lastDot = name.lastIndexOf ('.'); if (lastDot < 0) return ""; return name.substring (lastDot); } /** * * @param dir [null is ignored] * @param file [absolute overrides 'dir'] * @return */ public static File newFile (final File dir, final File file) { if (file == null) throw new IllegalArgumentException ("null input: file"); if ((dir == null) || file.isAbsolute ()) return file; return new File (dir, file.getPath ()); } /** * * @param dir [null is ignored] * @param file [absolute overrides 'dir'] * @return */ public static File newFile (final File dir, final String file) { if (file == null) throw new IllegalArgumentException ("null input: file"); final File fileFile = new File (file); if ((dir == null) || fileFile.isAbsolute ()) return fileFile; return new File (dir, file); } /** * * @param dir [null is ignored] * @param file [absolute overrides 'dir'] * @return */ public static File newFile (final String dir, final String file) { if (file == null) throw new IllegalArgumentException ("null input: file"); final File fileFile = new File (file); if ((dir == null) || fileFile.isAbsolute ()) return fileFile; return new File (dir, file); } /** * Renames 'source' to 'target' [intermediate directories are created if necessary]. If * 'target' exists and 'overwrite' is false, the method is a no-op. No exceptions are * thrown except for when input is invalid. If the operation fails half-way it can leave * some file system artifacts behind. * * @return true iff the renaming was actually performed. * * @param source file descriptor [file must exist] * @param target target file descriptor [an existing target may get deleted * if 'overwrite' is true] * @param overwrite if 'true', forces an existing target to be deleted * * @throws IllegalArgumentException if 'source' is null or file does not exist * @throws IllegalArgumentException if 'target' is null */ public static boolean renameFile (final File source, final File target, final boolean overwrite) { if ((source == null) || ! source.exists ()) throw new IllegalArgumentException ("invalid input source: [" + source + "]"); if (target == null) throw new IllegalArgumentException ("null input: target"); final boolean targetExists; if (! (targetExists = target.exists ()) || overwrite) { if (targetExists) { // need to delete the target first or the rename will fail: target.delete (); // not checking the result here: let the rename fail later } else { // note that File.renameTo() does not create intermediate directories on demand: final File targetDir = target.getParentFile (); if ((targetDir != null) && ! targetDir.equals (source.getParentFile ())) targetDir.mkdirs (); // TODO: clean this up on failure? } // note: this can fail for a number of reasons, including the target // being on a different drive/file system: return source.renameTo (target); } return false; } /** * A slightly stricter version of File.createTempFile() in J2SDK 1.3: it requires * that the caller provide an existing parent directory for the temp file. * This defers to File.createTempFile (prefix, extension, parentDir) after * normalizing 'extension'.

* * MT-safety: if several threads use this API concurrently, the temp files * created are guaranteed to get created without any collisions and correspond * to files that did not exist before. However, if such a temp file is deleted * at a later point, this method may reuse its file name. These MT-safety * guarantees do not hold if files are created in the same directory outside * of this method. * * @param parentDir parent dir for the temp file [may not be null and must exist] * @param prefix prefix pattern for the temp file name [only the first 3 * chars are guaranteed to be used] * @param extension pattern for the temp file name [null is equivalient to * ".tmp"; this is always normalized to start with "."; only the first 3 * non-"." chars are guaranteed to be used] * * @return writeable temp file descriptor [incorporates 'parentDir' in its pathname] * @throws IOException if a temp file could not be created */ public static File createTempFile (final File parentDir, final String prefix, String extension) throws IOException { if ((parentDir == null) || ! parentDir.exists ()) throw new IllegalArgumentException ("invalid parent directory: [" + parentDir + "]"); if ((prefix == null) || (prefix.length () < 3)) throw new IllegalArgumentException ("null or less than 3 chars long: " + prefix); if (extension == null) extension = ".tmp"; else if (extension.charAt (0) != '.') extension = ".".concat (extension); return File.createTempFile (prefix, extension, parentDir); } // protected: ............................................................. // package: ............................................................... // private: ............................................................... private Files () {} // prevent subclassing } // end of class // ----------------------------------------------------------------------------