| 1 | /* |
| 2 | * Copyright 2006 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package com.sun.tools.javac.processing; |
| 27 | |
| 28 | import java.io.BufferedReader; |
| 29 | import java.io.FileNotFoundException; |
| 30 | import java.io.IOException; |
| 31 | import java.io.InputStream; |
| 32 | import java.io.InputStreamReader; |
| 33 | import java.net.MalformedURLException; |
| 34 | import java.net.URL; |
| 35 | import java.util.ArrayList; |
| 36 | import java.util.Iterator; |
| 37 | import java.util.List; |
| 38 | import java.util.Set; |
| 39 | |
| 40 | /** |
| 41 | * Utility class to determine if a service can be found on the |
| 42 | * path that might be used to create a class loader. |
| 43 | * |
| 44 | * <p><b>This is NOT part of any API supported by Sun Microsystems. |
| 45 | * If you write code that depends on this, you do so at your own risk. |
| 46 | * This code and its internal interfaces are subject to change or |
| 47 | * deletion without notice.</b> |
| 48 | * |
| 49 | */ |
| 50 | // based on sun.misc.Service |
| 51 | class ServiceProxy { |
| 52 | static class ServiceConfigurationError extends Error { |
| 53 | static final long serialVersionUID = 7732091036771098303L; |
| 54 | |
| 55 | ServiceConfigurationError(String msg) { |
| 56 | super(msg); |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | private static final String prefix = "META-INF/services/"; |
| 61 | |
| 62 | private static void fail(Class service, String msg) |
| 63 | throws ServiceConfigurationError { |
| 64 | throw new ServiceConfigurationError(service.getName() + ": " + msg); |
| 65 | } |
| 66 | |
| 67 | private static void fail(Class service, URL u, int line, String msg) |
| 68 | throws ServiceConfigurationError { |
| 69 | fail(service, u + ":" + line + ": " + msg); |
| 70 | } |
| 71 | |
| 72 | /** |
| 73 | * Parse the content of the given URL as a provider-configuration file. |
| 74 | * |
| 75 | * @param service |
| 76 | * The service class for which providers are being sought; |
| 77 | * used to construct error detail strings |
| 78 | * |
| 79 | * @param url |
| 80 | * The URL naming the configuration file to be parsed |
| 81 | * |
| 82 | * @return true if the name of a service is found |
| 83 | * |
| 84 | * @throws ServiceConfigurationError |
| 85 | * If an I/O error occurs while reading from the given URL, or |
| 86 | * if a configuration-file format error is detected |
| 87 | */ |
| 88 | private static boolean parse(Class service, URL u) throws ServiceConfigurationError { |
| 89 | InputStream in = null; |
| 90 | BufferedReader r = null; |
| 91 | try { |
| 92 | in = u.openStream(); |
| 93 | r = new BufferedReader(new InputStreamReader(in, "utf-8")); |
| 94 | int lc = 1; |
| 95 | String ln; |
| 96 | while ((ln = r.readLine()) != null) { |
| 97 | int ci = ln.indexOf('#'); |
| 98 | if (ci >= 0) ln = ln.substring(0, ci); |
| 99 | ln = ln.trim(); |
| 100 | int n = ln.length(); |
| 101 | if (n != 0) { |
| 102 | if ((ln.indexOf(' ') >= 0) || (ln.indexOf('\t') >= 0)) |
| 103 | fail(service, u, lc, "Illegal configuration-file syntax"); |
| 104 | int cp = ln.codePointAt(0); |
| 105 | if (!Character.isJavaIdentifierStart(cp)) |
| 106 | fail(service, u, lc, "Illegal provider-class name: " + ln); |
| 107 | for (int i = Character.charCount(cp); i < n; i += Character.charCount(cp)) { |
| 108 | cp = ln.codePointAt(i); |
| 109 | if (!Character.isJavaIdentifierPart(cp) && (cp != '.')) |
| 110 | fail(service, u, lc, "Illegal provider-class name: " + ln); |
| 111 | } |
| 112 | return true; |
| 113 | } |
| 114 | } |
| 115 | } catch (FileNotFoundException x) { |
| 116 | return false; |
| 117 | } catch (IOException x) { |
| 118 | fail(service, ": " + x); |
| 119 | } finally { |
| 120 | try { |
| 121 | if (r != null) r.close(); |
| 122 | } catch (IOException y) { |
| 123 | fail(service, ": " + y); |
| 124 | } |
| 125 | try { |
| 126 | if (in != null) in.close(); |
| 127 | } catch (IOException y) { |
| 128 | fail(service, ": " + y); |
| 129 | } |
| 130 | } |
| 131 | return false; |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * Return true if a description for at least one service is found in the |
| 136 | * service configuration files in the given URLs. |
| 137 | */ |
| 138 | public static boolean hasService(Class<?> service, URL[] urls) |
| 139 | throws ServiceConfigurationError { |
| 140 | for (URL url: urls) { |
| 141 | try { |
| 142 | String fullName = prefix + service.getName(); |
| 143 | URL u = new URL(url, fullName); |
| 144 | boolean found = parse(service, u); |
| 145 | if (found) |
| 146 | return true; |
| 147 | } catch (MalformedURLException e) { |
| 148 | // should not happen; ignore it if it does |
| 149 | } |
| 150 | } |
| 151 | return false; |
| 152 | } |
| 153 | } |