Showing the changes to java/pkg/sun/nio/fs/AbstractFileTypeDetector.java (1 of 18352 files). Show all
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| 1 | +/* | |
| 2 | + * Copyright (c) 2008, 2011, 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.nio.file.Path; | |
| 29 | +import java.nio.file.spi.FileTypeDetector; | |
| 30 | +import java.util.Locale; | |
| 31 | +import java.io.IOException; | |
| 32 | + | |
| 33 | +/** | |
| 34 | + * Base implementation of FileTypeDetector | |
| 35 | + */ | |
| 36 | + | |
| 37 | +public abstract class AbstractFileTypeDetector | |
| 38 | + extends FileTypeDetector | |
| 39 | +{ | |
| 40 | + protected AbstractFileTypeDetector() { | |
| 41 | + super(); | |
| 42 | + } | |
| 43 | + | |
| 44 | + /** | |
| 45 | + * Invokes the appropriate probe method to guess a file's content type, | |
| 46 | + * and checks that the content type's syntax is valid. | |
| 47 | + */ | |
| 48 | + @Override | |
| 49 | + public final String probeContentType(Path file) throws IOException { | |
| 50 | + if (file == null) | |
| 51 | + throw new NullPointerException("'file' is null"); | |
| 52 | + String result = implProbeContentType(file); | |
| 53 | + return (result == null) ? null : parse(result); | |
| 54 | + } | |
| 55 | + | |
| 56 | + /** | |
| 57 | + * Probes the given file to guess its content type. | |
| 58 | + */ | |
| 59 | + protected abstract String implProbeContentType(Path file) | |
| 60 | + throws IOException; | |
| 61 | + | |
| 62 | + /** | |
| 63 | + * Parses a candidate content type into its type and subtype, returning | |
| 64 | + * null if either token is invalid. | |
| 65 | + */ | |
| 66 | + private static String parse(String s) { | |
| 67 | + int slash = s.indexOf('/'); | |
| 68 | + int semicolon = s.indexOf(';'); | |
| 69 | + if (slash < 0) | |
| 70 | + return null; // no subtype | |
| 71 | + String type = s.substring(0, slash).trim().toLowerCase(Locale.ENGLISH); | |
| 72 | + if (!isValidToken(type)) | |
| 73 | + return null; // invalid type | |
| 74 | + String subtype = (semicolon < 0) ? s.substring(slash + 1) : | |
| 75 | + s.substring(slash + 1, semicolon); | |
| 76 | + subtype = subtype.trim().toLowerCase(Locale.ENGLISH); | |
| 77 | + if (!isValidToken(subtype)) | |
| 78 | + return null; // invalid subtype | |
| 79 | + StringBuilder sb = new StringBuilder(type.length() + subtype.length() + 1); | |
| 80 | + sb.append(type); | |
| 81 | + sb.append('/'); | |
| 82 | + sb.append(subtype); | |
| 83 | + return sb.toString(); | |
| 84 | + } | |
| 85 | + | |
| 86 | + /** | |
| 87 | + * Special characters | |
| 88 | + */ | |
| 89 | + private static final String TSPECIALS = "()<>@,;:/[]?=\\\""; | |
| 90 | + | |
| 91 | + /** | |
| 92 | + * Returns true if the character is a valid token character. | |
| 93 | + */ | |
| 94 | + private static boolean isTokenChar(char c) { | |
| 95 | + return (c > 040) && (c < 0177) && (TSPECIALS.indexOf(c) < 0); | |
| 96 | + } | |
| 97 | + | |
| 98 | + /** | |
| 99 | + * Returns true if the given string is a legal type or subtype. | |
| 100 | + */ | |
| 101 | + private static boolean isValidToken(String s) { | |
| 102 | + int len = s.length(); | |
| 103 | + if (len == 0) | |
| 104 | + return false; | |
| 105 | + for (int i = 0; i < len; i++) { | |
| 106 | + if (!isTokenChar(s.charAt(i))) | |
| 107 | + return false; | |
| 108 | + } | |
| 109 | + return true; | |
| 110 | + } | |
| 111 | +} | |