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Java example source code file (MimeTypesFileTypeDetector.java)
The MimeTypesFileTypeDetector.java Java example source code/* * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package sun.nio.fs; import java.io.IOException; import java.nio.charset.Charset; import java.nio.file.Files; import java.nio.file.Path; import java.security.AccessController; import java.security.PrivilegedAction; import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.regex.Matcher; import java.util.regex.Pattern; /** * File type detector that uses a file extension to look up its MIME type * based on a mime.types file. */ class MimeTypesFileTypeDetector extends AbstractFileTypeDetector { // path to mime.types file private final Path mimeTypesFile; // map of extension to MIME type private Map<String,String> mimeTypeMap; // set to true when file loaded private volatile boolean loaded = false; public MimeTypesFileTypeDetector(Path filePath) { mimeTypesFile = filePath; } @Override protected String implProbeContentType(Path path) { Path fn = path.getFileName(); if (fn == null) return null; // no file name String ext = getExtension(fn.toString()); if (ext.isEmpty()) return null; // no extension loadMimeTypes(); if (mimeTypeMap == null || mimeTypeMap.isEmpty()) return null; // Case-sensitive search String mimeType; do { mimeType = mimeTypeMap.get(ext); if (mimeType == null) ext = getExtension(ext); } while (mimeType == null && !ext.isEmpty()); return mimeType; } // Get the extension of a file name. private static String getExtension(String name) { String ext = ""; if (name != null && !name.isEmpty()) { int dot = name.indexOf('.'); if ((dot >= 0) && (dot < name.length() - 1)) { ext = name.substring(dot + 1); } } return ext; } /** * Parse the mime types file, and store the type-extension mappings into * mimeTypeMap. The mime types file is not loaded until the first probe * to achieve the lazy initialization. It adopts double-checked locking * optimization to reduce the locking overhead. */ private void loadMimeTypes() { if (!loaded) { synchronized (this) { if (!loaded) { List<String> lines = AccessController.doPrivileged( new PrivilegedAction<List Other Java examples (source code examples)Here is a short list of links related to this Java MimeTypesFileTypeDetector.java source code file: |
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