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 | } |