1 | /* |
2 | * Copyright 2005-2006 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 javax.tools; |
27 | |
28 | import java.io.File; |
29 | import java.net.URL; |
30 | import java.net.URLClassLoader; |
31 | import java.net.MalformedURLException; |
32 | import java.util.Locale; |
33 | import java.util.logging.Logger; |
34 | import java.util.logging.Level; |
35 | import static java.util.logging.Level.*; |
36 | |
37 | /** |
38 | * Provides methods for locating tool providers, for example, |
39 | * providers of compilers. This class complements the |
40 | * functionality of {@link java.util.ServiceLoader}. |
41 | * |
42 | * @author Peter von der Ahé |
43 | * @since 1.6 |
44 | */ |
45 | public class ToolProvider { |
46 | |
47 | private ToolProvider() {} |
48 | |
49 | private static final String propertyName = "sun.tools.ToolProvider"; |
50 | private static final String loggerName = "javax.tools"; |
51 | |
52 | /* |
53 | * Define the system property "sun.tools.ToolProvider" to enable |
54 | * debugging: |
55 | * |
56 | * java ... -Dsun.tools.ToolProvider ... |
57 | */ |
58 | static <T> T trace(Level level, Object reason) { |
59 | // NOTE: do not make this method private as it affects stack traces |
60 | try { |
61 | if (System.getProperty(propertyName) != null) { |
62 | StackTraceElement[] st = Thread.currentThread().getStackTrace(); |
63 | String method = "???"; |
64 | String cls = ToolProvider.class.getName(); |
65 | if (st.length > 2) { |
66 | StackTraceElement frame = st[2]; |
67 | method = String.format((Locale)null, "%s(%s:%s)", |
68 | frame.getMethodName(), |
69 | frame.getFileName(), |
70 | frame.getLineNumber()); |
71 | cls = frame.getClassName(); |
72 | } |
73 | Logger logger = Logger.getLogger(loggerName); |
74 | if (reason instanceof Throwable) { |
75 | logger.logp(level, cls, method, |
76 | reason.getClass().getName(), (Throwable)reason); |
77 | } else { |
78 | logger.logp(level, cls, method, String.valueOf(reason)); |
79 | } |
80 | } |
81 | } catch (SecurityException ex) { |
82 | System.err.format((Locale)null, "%s: %s; %s%n", |
83 | ToolProvider.class.getName(), |
84 | reason, |
85 | ex.getLocalizedMessage()); |
86 | } |
87 | return null; |
88 | } |
89 | |
90 | /** |
91 | * Gets the Java™ programming language compiler provided |
92 | * with this platform. |
93 | * @return the compiler provided with this platform or |
94 | * {@code null} if no compiler is provided |
95 | */ |
96 | public static JavaCompiler getSystemJavaCompiler() { |
97 | if (Lazy.compilerClass == null) |
98 | return trace(WARNING, "Lazy.compilerClass == null"); |
99 | try { |
100 | return Lazy.compilerClass.newInstance(); |
101 | } catch (Throwable e) { |
102 | return trace(WARNING, e); |
103 | } |
104 | } |
105 | |
106 | /** |
107 | * Returns the class loader for tools provided with this platform. |
108 | * This does not include user-installed tools. Use the |
109 | * {@linkplain java.util.ServiceLoader service provider mechanism} |
110 | * for locating user installed tools. |
111 | * |
112 | * @return the class loader for tools provided with this platform |
113 | * or {@code null} if no tools are provided |
114 | */ |
115 | public static ClassLoader getSystemToolClassLoader() { |
116 | if (Lazy.compilerClass == null) |
117 | return trace(WARNING, "Lazy.compilerClass == null"); |
118 | return Lazy.compilerClass.getClassLoader(); |
119 | } |
120 | |
121 | /** |
122 | * This class will not be initialized until one of the above |
123 | * methods are called. This ensures that searching for the |
124 | * compiler does not affect platform start up. |
125 | */ |
126 | static class Lazy { |
127 | private static final String defaultJavaCompilerName |
128 | = "com.sun.tools.javac.api.JavacTool"; |
129 | private static final String[] defaultToolsLocation |
130 | = { "lib", "tools.jar" }; |
131 | static final Class<? extends JavaCompiler> compilerClass; |
132 | static { |
133 | Class<? extends JavaCompiler> c = null; |
134 | try { |
135 | c = findClass().asSubclass(JavaCompiler.class); |
136 | } catch (Throwable t) { |
137 | trace(WARNING, t); |
138 | } |
139 | compilerClass = c; |
140 | } |
141 | |
142 | private static Class<?> findClass() |
143 | throws MalformedURLException, ClassNotFoundException |
144 | { |
145 | try { |
146 | return enableAsserts(Class.forName(defaultJavaCompilerName, false, null)); |
147 | } catch (ClassNotFoundException e) { |
148 | trace(FINE, e); |
149 | } |
150 | File file = new File(System.getProperty("java.home")); |
151 | if (file.getName().equalsIgnoreCase("jre")) |
152 | file = file.getParentFile(); |
153 | for (String name : defaultToolsLocation) |
154 | file = new File(file, name); |
155 | URL[] urls = {file.toURI().toURL()}; |
156 | trace(FINE, urls[0].toString()); |
157 | ClassLoader cl = URLClassLoader.newInstance(urls); |
158 | cl.setPackageAssertionStatus("com.sun.tools.javac", true); |
159 | return Class.forName(defaultJavaCompilerName, false, cl); |
160 | } |
161 | |
162 | private static Class<?> enableAsserts(Class<?> cls) { |
163 | try { |
164 | ClassLoader loader = cls.getClassLoader(); |
165 | if (loader != null) |
166 | loader.setPackageAssertionStatus("com.sun.tools.javac", true); |
167 | else |
168 | trace(FINE, "loader == null"); |
169 | } catch (SecurityException ex) { |
170 | trace(FINE, ex); |
171 | } |
172 | return cls; |
173 | } |
174 | } |
175 | } |