1 /*
2 * Copyright (c) 2015, 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 package jdk.internal.logger;
26
27 import java.io.FilePermission;
28 import java.security.AccessController;
29 import java.security.Permission;
30 import java.security.PrivilegedAction;
31 import java.util.Iterator;
32 import java.util.Locale;
33 import java.util.ServiceConfigurationError;
34 import java.util.ServiceLoader;
35 import sun.security.util.SecurityConstants;
36 import sun.security.action.GetPropertyAction;
37
38 /**
39 * Helper class used to load the {@link java.lang.System.LoggerFinder}.
40 */
41 public final class LoggerFinderLoader {
42 private static volatile System.LoggerFinder service;
43 private static final Object lock = new int[0];
44 static final Permission CLASSLOADER_PERMISSION =
45 SecurityConstants.GET_CLASSLOADER_PERMISSION;
46 static final Permission READ_PERMISSION =
47 new FilePermission("<<ALL FILES>>",
48 SecurityConstants.FILE_READ_ACTION);
49 public static final RuntimePermission LOGGERFINDER_PERMISSION =
50 new RuntimePermission("loggerFinder");
51
52 // This is used to control how the LoggerFinderLoader handles
53 // errors when instantiating the LoggerFinder provider.
54 // ERROR => throws ServiceConfigurationError
55 // WARNING => Do not fail, use plain default (simple logger) implementation,
56 // prints warning on console. (this is the default)
57 // DEBUG => Do not fail, use plain default (simple logger) implementation,
58 // prints warning and exception stack trace on console.
59 // QUIET => Do not fail and stay silent.
60 private static enum ErrorPolicy { ERROR, WARNING, DEBUG, QUIET };
61
62 // This class is static and cannot be instantiated.
63 private LoggerFinderLoader() {
64 throw new InternalError("LoggerFinderLoader cannot be instantiated");
65 }
66
67
68 // Return the loaded LoggerFinder, or load it if not already loaded.
69 private static System.LoggerFinder service() {
70 if (service != null) return service;
71 synchronized(lock) {
72 if (service != null) return service;
73 service = loadLoggerFinder();
74 }
75 // Since the LoggerFinder is already loaded - we can stop using
76 // temporary loggers.
77 BootstrapLogger.redirectTemporaryLoggers();
78 return service;
79 }
80
81 // Get configuration error policy
82 private static ErrorPolicy configurationErrorPolicy() {
83 String errorPolicy =
84 GetPropertyAction.getProperty("jdk.logger.finder.error");
85 if (errorPolicy == null || errorPolicy.isEmpty()) {
86 return ErrorPolicy.WARNING;
87 }
88 try {
89 return ErrorPolicy.valueOf(errorPolicy.toUpperCase(Locale.ROOT));
90 } catch (IllegalArgumentException x) {
91 return ErrorPolicy.WARNING;
92 }
93 }
94
95 // Whether multiple provider should be considered as an error.
96 // This is further submitted to the configuration error policy.
97 private static boolean ensureSingletonProvider() {
98 return Boolean.parseBoolean(
99 GetPropertyAction.getProperty("jdk.logger.finder.singleton"));
100 }
101
102 private static Iterator<System.LoggerFinder> findLoggerFinderProviders() {
103 final Iterator<System.LoggerFinder> iterator;
104 if (System.getSecurityManager() == null) {
105 iterator = ServiceLoader.load(System.LoggerFinder.class,
106 ClassLoader.getSystemClassLoader()).iterator();
107 } else {
108 final PrivilegedAction<Iterator<System.LoggerFinder>> pa =
109 () -> ServiceLoader.load(System.LoggerFinder.class,
110 ClassLoader.getSystemClassLoader()).iterator();
111 iterator = AccessController.doPrivileged(pa, null,
112 LOGGERFINDER_PERMISSION, CLASSLOADER_PERMISSION,
113 READ_PERMISSION);
114 }
115 return iterator;
116 }
117
118 // Loads the LoggerFinder using ServiceLoader. If no LoggerFinder
119 // is found returns the default (possibly JUL based) implementation
120 private static System.LoggerFinder loadLoggerFinder() {
121 System.LoggerFinder result;
122 try {
123 // Iterator iterates with the access control context stored
124 // at ServiceLoader creation time.
125 final Iterator<System.LoggerFinder> iterator =
126 findLoggerFinderProviders();
127 if (iterator.hasNext()) {
128 result = iterator.next();
129 if (iterator.hasNext() && ensureSingletonProvider()) {
130 throw new ServiceConfigurationError(
131 "More than on LoggerFinder implementation");
132 }
133 } else {
134 result = loadDefaultImplementation();
135 }
136 } catch (Error | RuntimeException x) {
137 // next caller will get the plain default impl (not linked
138 // to java.util.logging)
139 service = result = new DefaultLoggerFinder();
140 ErrorPolicy errorPolicy = configurationErrorPolicy();
141 if (errorPolicy == ErrorPolicy.ERROR) {
142 // rethrow any exception as a ServiceConfigurationError.
143 if (x instanceof Error) {
144 throw x;
145 } else {
146 throw new ServiceConfigurationError(
147 "Failed to instantiate LoggerFinder provider; Using default.", x);
148 }
149 } else if (errorPolicy != ErrorPolicy.QUIET) {
150 // if QUIET just silently use the plain default impl
151 // otherwise, log a warning, possibly adding the exception
152 // stack trace (if DEBUG is specified).
153 SimpleConsoleLogger logger =
154 new SimpleConsoleLogger("jdk.internal.logger", false);
155 logger.log(System.Logger.Level.WARNING,
156 "Failed to instantiate LoggerFinder provider; Using default.");
157 if (errorPolicy == ErrorPolicy.DEBUG) {
158 logger.log(System.Logger.Level.WARNING,
159 "Exception raised trying to instantiate LoggerFinder", x);
160 }
161 }
162 }
163 return result;
164 }
165
166 private static System.LoggerFinder loadDefaultImplementation() {
167 final SecurityManager sm = System.getSecurityManager();
168 final Iterator<DefaultLoggerFinder> iterator;
169 if (sm == null) {
170 iterator = ServiceLoader.loadInstalled(DefaultLoggerFinder.class).iterator();
171 } else {
172 // We use limited do privileged here - the minimum set of
173 // permissions required to 'see' the META-INF/services resources
174 // seems to be CLASSLOADER_PERMISSION and READ_PERMISSION.
175 // Note that do privileged is required because
176 // otherwise the SecurityManager will prevent the ServiceLoader
177 // from seeing the installed provider.
178 PrivilegedAction<Iterator<DefaultLoggerFinder>> pa = () ->
179 ServiceLoader.loadInstalled(DefaultLoggerFinder.class).iterator();
180 iterator = AccessController.doPrivileged(pa, null,
181 LOGGERFINDER_PERMISSION, CLASSLOADER_PERMISSION,
182 READ_PERMISSION);
183 }
184 DefaultLoggerFinder result = null;
185 try {
186 // Iterator iterates with the access control context stored
187 // at ServiceLoader creation time.
188 if (iterator.hasNext()) {
189 result = iterator.next();
190 }
191 } catch (RuntimeException x) {
192 throw new ServiceConfigurationError(
193 "Failed to instantiate default LoggerFinder", x);
194 }
195 if (result == null) {
196 result = new DefaultLoggerFinder();
197 }
198 return result;
199 }
200
201 public static System.LoggerFinder getLoggerFinder() {
202 final SecurityManager sm = System.getSecurityManager();
203 if (sm != null) {
204 sm.checkPermission(LOGGERFINDER_PERMISSION);
205 }
206 return service();
207 }
208
209 }