Java tutorial
/* * Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 1996-2002. * All rights reserved. Software written by Ian F. Darwin and others. * $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $ * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * Java, the Duke mascot, and all variants of Sun's Java "steaming coffee * cup" logo are trademarks of Sun Microsystems. Sun's, and James Gosling's, * pioneering role in inventing and promulgating (and standardizing) the Java * language and environment is gratefully acknowledged. * * The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for * inventing predecessor languages C and C++ is also gratefully acknowledged. */ import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.util.Enumeration; import java.util.SortedSet; import java.util.TreeSet; import java.util.zip.ZipEntry; import java.util.zip.ZipFile; /** * UnZip -- print or unzip a JAR or PKZIP file using java.util.zip. Command-line * version: extracts files. * * @author Ian Darwin, Ian@DarwinSys.com $Id: UnZip.java,v 1.7 2004/03/07 * 17:40:35 ian Exp $ */ public class UnZip { /** Constants for mode listing or mode extracting. */ public static final int LIST = 0, EXTRACT = 1; /** Whether we are extracting or just printing TOC */ protected int mode = LIST; /** The ZipFile that is used to read an archive */ protected ZipFile zippy; /** The buffer for reading/writing the ZipFile data */ protected byte[] b; /** * Simple main program, construct an UnZipper, process each .ZIP file from * argv[] through that object. */ public static void main(String[] argv) { UnZip u = new UnZip(); for (int i = 0; i < argv.length; i++) { if ("-x".equals(argv[i])) { u.setMode(EXTRACT); continue; } String candidate = argv[i]; // System.err.println("Trying path " + candidate); if (candidate.endsWith(".zip") || candidate.endsWith(".jar")) u.unZip(candidate); else System.err.println("Not a zip file? " + candidate); } System.err.println("All done!"); } /** Construct an UnZip object. Just allocate the buffer */ UnZip() { b = new byte[8092]; } /** Set the Mode (list, extract). */ protected void setMode(int m) { if (m == LIST || m == EXTRACT) mode = m; } /** Cache of paths we've mkdir()ed. */ protected SortedSet dirsMade; /** For a given Zip file, process each entry. */ public void unZip(String fileName) { dirsMade = new TreeSet(); try { zippy = new ZipFile(fileName); Enumeration all = zippy.entries(); while (all.hasMoreElements()) { getFile((ZipEntry) all.nextElement()); } } catch (IOException err) { System.err.println("IO Error: " + err); return; } } protected boolean warnedMkDir = false; /** * Process one file from the zip, given its name. Either print the name, or * create the file on disk. */ protected void getFile(ZipEntry e) throws IOException { String zipName = e.getName(); switch (mode) { case EXTRACT: if (zipName.startsWith("/")) { if (!warnedMkDir) System.out.println("Ignoring absolute paths"); warnedMkDir = true; zipName = zipName.substring(1); } // if a directory, just return. We mkdir for every file, // since some widely-used Zip creators don't put out // any directory entries, or put them in the wrong place. if (zipName.endsWith("/")) { return; } // Else must be a file; open the file for output // Get the directory part. int ix = zipName.lastIndexOf('/'); if (ix > 0) { String dirName = zipName.substring(0, ix); if (!dirsMade.contains(dirName)) { File d = new File(dirName); // If it already exists as a dir, don't do anything if (!(d.exists() && d.isDirectory())) { // Try to create the directory, warn if it fails System.out.println("Creating Directory: " + dirName); if (!d.mkdirs()) { System.err.println("Warning: unable to mkdir " + dirName); } dirsMade.add(dirName); } } } System.err.println("Creating " + zipName); FileOutputStream os = new FileOutputStream(zipName); InputStream is = zippy.getInputStream(e); int n = 0; while ((n = is.read(b)) > 0) os.write(b, 0, n); is.close(); os.close(); break; case LIST: // Not extracting, just list if (e.isDirectory()) { System.out.println("Directory " + zipName); } else { System.out.println("File " + zipName); } break; default: throw new IllegalStateException("mode value (" + mode + ") bad"); } } }