1 /* 2 * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package sun.nio.fs; 27 28 import java.io.IOException; 29 import java.nio.file.Path; 30 import java.security.AccessController; 31 import java.security.PrivilegedAction; 32 33 /** 34 * File type detector that uses the libmagic to guess the MIME type of a file. 35 */ 36 37 class MagicFileTypeDetector extends AbstractFileTypeDetector { 38 39 private static final String UNKNOWN_MIME_TYPE = "application/octet-stream"; 40 41 // true if libmagic is available and successfully loaded 42 private final boolean libmagicAvailable; 43 44 public MagicFileTypeDetector() { 45 libmagicAvailable = initialize0(); 46 } 47 48 @Override 49 protected String implProbeContentType(Path obj) throws IOException { 50 if (!libmagicAvailable || !(obj instanceof UnixPath)) 51 return null; 52 53 UnixPath path = (UnixPath) obj; 54 path.checkRead(); 55 56 NativeBuffer buffer = NativeBuffers.asNativeBuffer(path.getByteArrayForSysCalls()); 57 try { 58 byte[] type = probe0(buffer.address()); 59 String mimeType = (type == null) ? null : new String(type); 60 return UNKNOWN_MIME_TYPE.equals(mimeType) ? null : mimeType; 61 } finally { 62 buffer.release(); 63 } 64 } 65 66 private static native boolean initialize0(); 67 68 private static native byte[] probe0(long pathAddress); 69 70 static { 71 AccessController.doPrivileged(new PrivilegedAction<Void>() { 72 @Override 73 public Void run() { 74 System.loadLibrary("nio"); 75 return null; 76 } 77 }); 78 } 79 }