Java tutorial
/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright (c) 1997-2017 Oracle and/or its affiliates. All rights reserved. * * The contents of this file are subject to the terms of either the GNU * General Public License Version 2 only ("GPL") or the Common Development * and Distribution License("CDDL") (collectively, the "License"). You * may not use this file except in compliance with the License. You can * obtain a copy of the License at * https://oss.oracle.com/licenses/CDDL+GPL-1.1 * or LICENSE.txt. See the License for the specific * language governing permissions and limitations under the License. * * When distributing the software, include this License Header Notice in each * file and include the License file at LICENSE.txt. * * GPL Classpath Exception: * Oracle designates this particular file as subject to the "Classpath" * exception as provided by Oracle in the GPL Version 2 section of the License * file that accompanied this code. * * Modifications: * If applicable, add the following below the License Header, with the fields * enclosed by brackets [] replaced by your own identifying information: * "Portions Copyright [year] [name of copyright owner]" * * Contributor(s): * If you wish your version of this file to be governed by only the CDDL or * only the GPL Version 2, indicate your decision by adding "[Contributor] * elects to include this software in this distribution under the [CDDL or GPL * Version 2] license." If you don't indicate a single choice of license, a * recipient has the option to distribute your version of this file under * either the CDDL, the GPL Version 2 or to extend the choice of license to * its licensees as provided above. However, if you add GPL Version 2 code * and therefore, elected the GPL Version 2 license, then the option applies * only if the new code is made subject to such option by the copyright * holder. */ package javax.activation; import java.io.*; import java.net.*; import java.util.*; import java.security.AccessController; import java.security.PrivilegedAction; import com.sun.activation.registries.MimeTypeFile; import com.sun.activation.registries.LogSupport; /** * This class extends FileTypeMap and provides data typing of files * via their file extension. It uses the <code>.mime.types</code> format. <p> * * <b>MIME types file search order:</b><p> * The MimetypesFileTypeMap looks in various places in the user's * system for MIME types file entries. When requests are made * to search for MIME types in the MimetypesFileTypeMap, it searches * MIME types files in the following order: * <ol> * <li> Programmatically added entries to the MimetypesFileTypeMap instance. * <li> The file <code>.mime.types</code> in the user's home directory. * <li> The file <code>mime.types</code> in the Java runtime. * <li> The file or resources named <code>META-INF/mime.types</code>. * <li> The file or resource named <code>META-INF/mimetypes.default</code> * (usually found only in the <code>activation.jar</code> file). * </ol> * <p> * (The current implementation looks for the <code>mime.types</code> file * in the Java runtime in the directory <code><i>java.home</i>/conf</code> * if it exists, and otherwise in the directory * <code><i>java.home</i>/lib</code>, where <i>java.home</i> is the value * of the "java.home" System property. Note that the "conf" directory was * introduced in JDK 9.) * <p> * <b>MIME types file format:</b><p> * * <code> * # comments begin with a '#'<br> * # the format is <mime type> <space separated file extensions><br> * # for example:<br> * text/plain txt text TXT<br> * # this would map file.txt, file.text, and file.TXT to<br> * # the mime type "text/plain"<br> * </code> * * @author Bart Calder * @author Bill Shannon */ public class MimetypesFileTypeMap extends FileTypeMap { /* * We manage a collection of databases, searched in order. */ private MimeTypeFile[] DB; private static final int PROG = 0; // programmatically added entries private static final String defaultType = "application/octet-stream"; private static final String confDir; static { String dir = null; try { dir = (String) AccessController.doPrivileged(new PrivilegedAction() { public Object run() { String home = System.getProperty("java.home"); String newdir = home + File.separator + "conf"; File conf = new File(newdir); if (conf.exists()) return newdir + File.separator; else return home + File.separator + "lib" + File.separator; } }); } catch (Exception ex) { // ignore any exceptions } confDir = dir; } /** * The default constructor. */ public MimetypesFileTypeMap() { Vector dbv = new Vector(5); // usually 5 or less databases MimeTypeFile mf = null; dbv.addElement(null); // place holder for PROG entry LogSupport.log("MimetypesFileTypeMap: load HOME"); try { String user_home = System.getProperty("user.home"); if (user_home != null) { String path = user_home + File.separator + ".mime.types"; mf = loadFile(path); if (mf != null) dbv.addElement(mf); } } catch (SecurityException ex) { } LogSupport.log("MimetypesFileTypeMap: load SYS"); try { // check system's home if (confDir != null) { mf = loadFile(confDir + "mime.types"); if (mf != null) dbv.addElement(mf); } } catch (SecurityException ex) { } LogSupport.log("MimetypesFileTypeMap: load JAR"); // load from the app's jar file loadAllResources(dbv, "META-INF/mime.types"); LogSupport.log("MimetypesFileTypeMap: load DEF"); mf = loadResource("/META-INF/mimetypes.default"); if (mf != null) dbv.addElement(mf); DB = new MimeTypeFile[dbv.size()]; dbv.copyInto(DB); } /** * Load from the named resource. */ private MimeTypeFile loadResource(String name) { InputStream clis = null; try { clis = SecuritySupport.getResourceAsStream(this.getClass(), name); if (clis != null) { MimeTypeFile mf = new MimeTypeFile(clis); if (LogSupport.isLoggable()) LogSupport.log("MimetypesFileTypeMap: successfully " + "loaded mime types file: " + name); return mf; } else { if (LogSupport.isLoggable()) LogSupport.log("MimetypesFileTypeMap: not loading " + "mime types file: " + name); } } catch (IOException e) { if (LogSupport.isLoggable()) LogSupport.log("MimetypesFileTypeMap: can't load " + name, e); } catch (SecurityException sex) { if (LogSupport.isLoggable()) LogSupport.log("MimetypesFileTypeMap: can't load " + name, sex); } finally { try { if (clis != null) clis.close(); } catch (IOException ex) { } // ignore it } return null; } /** * Load all of the named resource. */ private void loadAllResources(Vector v, String name) { boolean anyLoaded = false; try { URL[] urls; ClassLoader cld = null; // First try the "application's" class loader. cld = SecuritySupport.getContextClassLoader(); if (cld == null) cld = this.getClass().getClassLoader(); if (cld != null) urls = SecuritySupport.getResources(cld, name); else urls = SecuritySupport.getSystemResources(name); if (urls != null) { if (LogSupport.isLoggable()) LogSupport.log("MimetypesFileTypeMap: getResources"); for (int i = 0; i < urls.length; i++) { URL url = urls[i]; InputStream clis = null; if (LogSupport.isLoggable()) LogSupport.log("MimetypesFileTypeMap: URL " + url); try { clis = SecuritySupport.openStream(url); if (clis != null) { v.addElement(new MimeTypeFile(clis)); anyLoaded = true; if (LogSupport.isLoggable()) LogSupport.log("MimetypesFileTypeMap: " + "successfully loaded " + "mime types from URL: " + url); } else { if (LogSupport.isLoggable()) LogSupport.log( "MimetypesFileTypeMap: " + "not loading " + "mime types from URL: " + url); } } catch (IOException ioex) { if (LogSupport.isLoggable()) LogSupport.log("MimetypesFileTypeMap: can't load " + url, ioex); } catch (SecurityException sex) { if (LogSupport.isLoggable()) LogSupport.log("MimetypesFileTypeMap: can't load " + url, sex); } finally { try { if (clis != null) clis.close(); } catch (IOException cex) { } } } } } catch (Exception ex) { if (LogSupport.isLoggable()) LogSupport.log("MimetypesFileTypeMap: can't load " + name, ex); } // if failed to load anything, fall back to old technique, just in case if (!anyLoaded) { LogSupport.log("MimetypesFileTypeMap: !anyLoaded"); MimeTypeFile mf = loadResource("/" + name); if (mf != null) v.addElement(mf); } } /** * Load the named file. */ private MimeTypeFile loadFile(String name) { MimeTypeFile mtf = null; try { mtf = new MimeTypeFile(name); } catch (IOException e) { // e.printStackTrace(); } return mtf; } /** * Construct a MimetypesFileTypeMap with programmatic entries * added from the named file. * * @param mimeTypeFileName the file name * @exception IOException for errors reading the file */ public MimetypesFileTypeMap(String mimeTypeFileName) throws IOException { this(); DB[PROG] = new MimeTypeFile(mimeTypeFileName); } /** * Construct a MimetypesFileTypeMap with programmatic entries * added from the InputStream. * * @param is the input stream to read from */ public MimetypesFileTypeMap(InputStream is) { this(); try { DB[PROG] = new MimeTypeFile(is); } catch (IOException ex) { // XXX - really should throw it } } /** * Prepend the MIME type values to the registry. * * @param mime_types A .mime.types formatted string of entries. */ public synchronized void addMimeTypes(String mime_types) { // check to see if we have created the registry if (DB[PROG] == null) DB[PROG] = new MimeTypeFile(); // make one DB[PROG].appendToRegistry(mime_types); } /** * Return the MIME type of the file object. * The implementation in this class calls * <code>getContentType(f.getName())</code>. * * @param f the file * @return the file's MIME type */ public String getContentType(File f) { return this.getContentType(f.getName()); } /** * Return the MIME type based on the specified file name. * The MIME type entries are searched as described above under * <i>MIME types file search order</i>. * If no entry is found, the type "application/octet-stream" is returned. * * @param filename the file name * @return the file's MIME type */ public synchronized String getContentType(String filename) { int dot_pos = filename.lastIndexOf("."); // period index if (dot_pos < 0) return defaultType; String file_ext = filename.substring(dot_pos + 1); if (file_ext.length() == 0) return defaultType; for (int i = 0; i < DB.length; i++) { if (DB[i] == null) continue; String result = DB[i].getMIMETypeString(file_ext); if (result != null) return result; } return defaultType; } /** * for debugging... * public static void main(String[] argv) throws Exception { MimetypesFileTypeMap map = new MimetypesFileTypeMap(); System.out.println("File " + argv[0] + " has MIME type " + map.getContentType(argv[0])); System.exit(0); } */ }