1 /*
2 * Copyright (c) 2015, 2016, 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 jdk.internal.logger;
27
28 import java.lang.ref.Reference;
29 import java.lang.ref.WeakReference;
30 import java.util.HashMap;
31 import java.util.Map;
32 import java.util.function.Function;
33 import java.util.Objects;
34 import java.lang.System.LoggerFinder;
35 import java.lang.System.Logger;
36 import java.lang.ref.ReferenceQueue;
37 import java.lang.reflect.Module;
38 import java.security.AccessController;
39 import java.security.PrivilegedAction;
40 import java.util.Collection;
41 import java.util.ResourceBundle;
42
43 /**
44 * Internal Service Provider Interface (SPI) that makes it possible to use
45 * {@code java.util.logging} as backend when the {@link
46 * sun.util.logging.internal.LoggingProviderImpl
47 * sun.util.logging.internal.LoggingProviderImpl} is present.
48 * <p>
49 * The JDK default implementation of the {@link LoggerFinder} will
50 * attempt to locate and load an {@linkplain
51 * java.util.ServiceLoader#loadInstalled(java.lang.Class) installed}
52 * implementation of the {@code DefaultLoggerFinder}. If {@code java.util.logging}
53 * is present, this will usually resolve to an instance of {@link
54 * sun.util.logging.internal.LoggingProviderImpl sun.util.logging.internal.LoggingProviderImpl}.
55 * Otherwise, if no concrete service provider is declared for
56 * {@code DefaultLoggerFinder}, the default implementation provided by this class
57 * will be used.
58 * <p>
59 * When the {@link sun.util.logging.internal.LoggingProviderImpl
60 * sun.util.logging.internal.LoggingProviderImpl} is not present then the
61 * default implementation provided by this class is to use a simple logger
62 * that will log messages whose level is INFO and above to the console.
63 * These simple loggers are not configurable.
64 * <p>
65 * When configuration is needed, an application should either link with
66 * {@code java.util.logging} - and use the {@code java.util.logging} for
67 * configuration, or link with {@link LoggerFinder another implementation}
68 * of the {@link LoggerFinder}
69 * that provides the necessary configuration.
70 *
71 * @apiNote Programmers are not expected to call this class directly.
72 * Instead they should rely on the static methods defined by {@link
73 * java.lang.System java.lang.System} or {@link sun.util.logging.PlatformLogger
74 * sun.util.logging.PlatformLogger}.
75 *
76 * @see java.lang.System.LoggerFinder
77 * @see jdk.internal.logger
78 * @see sun.util.logging.internal
79 *
80 */
81 public class DefaultLoggerFinder extends LoggerFinder {
82
83 static final RuntimePermission LOGGERFINDER_PERMISSION =
84 new RuntimePermission("loggerFinder");
85
86 /**
87 * Creates a new instance of DefaultLoggerFinder.
88 * @throws SecurityException if the calling code does not have the
89 * {@code RuntimePermission("loggerFinder")}
90 */
91 protected DefaultLoggerFinder() {
92 this(checkPermission());
93 }
94
95 private DefaultLoggerFinder(Void unused) {
96 // nothing to do.
97 }
98
99 private static Void checkPermission() {
100 final SecurityManager sm = System.getSecurityManager();
101 if (sm != null) {
102 sm.checkPermission(LOGGERFINDER_PERMISSION);
103 }
104 return null;
105 }
106
107 // SharedLoggers is a default cache of loggers used when JUL is not
108 // present - in that case we use instances of SimpleConsoleLogger which
109 // cannot be directly configure through public APIs.
110 //
111 // We can therefore afford to simply maintain two domains - one for the
112 // system, and one for the application.
113 //
114 static final class SharedLoggers {
115 private final Map<String, Reference<Logger>> loggers =
116 new HashMap<>();
117 private final ReferenceQueue<Logger> queue = new ReferenceQueue<>();
118
119 synchronized Logger get(Function<String, Logger> loggerSupplier, final String name) {
120 Reference<? extends Logger> ref = loggers.get(name);
121 Logger w = ref == null ? null : ref.get();
122 if (w == null) {
123 w = loggerSupplier.apply(name);
124 loggers.put(name, new WeakReference<>(w, queue));
125 }
126
127 // Remove stale mapping...
128 Collection<Reference<Logger>> values = null;
129 while ((ref = queue.poll()) != null) {
130 if (values == null) values = loggers.values();
131 values.remove(ref);
132 }
133 return w;
134 }
135
136 final static SharedLoggers system = new SharedLoggers();
137 final static SharedLoggers application = new SharedLoggers();
138 }
139
140 public static boolean isSystem(Module m) {
141 return AccessController.doPrivileged(new PrivilegedAction<>() {
142 @Override
143 public Boolean run() {
144 final ClassLoader moduleCL = m.getClassLoader();
145 if (moduleCL == null) return true;
146 ClassLoader cl = ClassLoader.getPlatformClassLoader();
147 while (cl != null && moduleCL != cl) {
148 cl = cl.getParent();
149 }
150 // returns true if moduleCL is the platform class loader
151 // or one of its ancestors.
152 return moduleCL == cl;
153 }
154 });
155 }
156
157 @Override
158 public final Logger getLogger(String name, Module module) {
159 Objects.requireNonNull(name, "name");
160 Objects.requireNonNull(module, "module");
161 checkPermission();
162 return demandLoggerFor(name, module);
163 }
164
165 @Override
166 public final Logger getLocalizedLogger(String name, ResourceBundle bundle,
167 Module module) {
168 return super.getLocalizedLogger(name, bundle, module);
169 }
170
171 /**
172 * Returns a {@link Logger logger} suitable for use within the
173 * given {@code module}.
174 *
175 * @implSpec The default implementation for this method is to return a
176 * simple logger that will print all messages of INFO level and above
177 * to the console. That simple logger is not configurable.
178 *
179 * @param name The name of the logger.
180 * @param module The module on behalf of which the logger is created.
181 * @return A {@link Logger logger} suitable for the application usage.
182 * @throws SecurityException if the calling code does not have the
183 * {@code RuntimePermission("loggerFinder")}.
184 */
185 protected Logger demandLoggerFor(String name, Module module) {
186 checkPermission();
187 if (isSystem(module)) {
188 return SharedLoggers.system.get(SimpleConsoleLogger::makeSimpleLogger, name);
189 } else {
190 return SharedLoggers.application.get(SimpleConsoleLogger::makeSimpleLogger, name);
191 }
192 }
193
194 }