1/*
2 * Copyright (c) 2009, 2013, 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
27package sun.util.logging;
28
29import java.lang.reflect.Field;
30import java.security.AccessController;
31import java.security.PrivilegedAction;
32import java.util.Date;
33
34/**
35 * Internal API to support JRE implementation to detect if the java.util.logging
36 * support is available but with no dependency on the java.util.logging
37 * classes.  This LoggingSupport class provides several static methods to
38 * access the java.util.logging functionality that requires the caller
39 * to ensure that the logging support is {@linkplain #isAvailable available}
40 * before invoking it.
41 *
42 * @see sun.util.logging.PlatformLogger if you want to log messages even
43 * if the logging support is not available
44 */
45public class LoggingSupport {
46    private LoggingSupport() { }
47
48    private static final LoggingProxy proxy =
49        AccessController.doPrivileged(new PrivilegedAction<LoggingProxy>() {
50            public LoggingProxy run() {
51                try {
52                    // create a LoggingProxyImpl instance when
53                    // java.util.logging classes exist
54                    Class<?> c = Class.forName("java.util.logging.LoggingProxyImpl", true, null);
55                    Field f = c.getDeclaredField("INSTANCE");
56                    f.setAccessible(true);
57                    return (LoggingProxy) f.get(null);
58                } catch (ClassNotFoundException cnf) {
59                    return null;
60                } catch (NoSuchFieldException e) {
61                    throw new AssertionError(e);
62                } catch (IllegalAccessException e) {
63                    throw new AssertionError(e);
64                }
65            }});
66
67    /**
68     * Returns true if java.util.logging support is available.
69     */
70    public static boolean isAvailable() {
71        return proxy != null;
72    }
73
74    private static void ensureAvailable() {
75        if (proxy == null)
76            throw new AssertionError("Should not here");
77    }
78
79    public static java.util.List<String> getLoggerNames() {
80        ensureAvailable();
81        return proxy.getLoggerNames();
82    }
83    public static String getLoggerLevel(String loggerName) {
84        ensureAvailable();
85        return proxy.getLoggerLevel(loggerName);
86    }
87
88    public static void setLoggerLevel(String loggerName, String levelName) {
89        ensureAvailable();
90        proxy.setLoggerLevel(loggerName, levelName);
91    }
92
93    public static String getParentLoggerName(String loggerName) {
94        ensureAvailable();
95        return proxy.getParentLoggerName(loggerName);
96    }
97
98    public static Object getLogger(String name) {
99        ensureAvailable();
100        return proxy.getLogger(name);
101    }
102
103    public static Object getLevel(Object logger) {
104        ensureAvailable();
105        return proxy.getLevel(logger);
106    }
107
108    public static void setLevel(Object logger, Object newLevel) {
109        ensureAvailable();
110        proxy.setLevel(logger, newLevel);
111    }
112
113    public static boolean isLoggable(Object logger, Object level) {
114        ensureAvailable();
115        return proxy.isLoggable(logger,level);
116    }
117
118    public static void log(Object logger, Object level, String msg) {
119        ensureAvailable();
120        proxy.log(logger, level, msg);
121    }
122
123    public static void log(Object logger, Object level, String msg, Throwable t) {
124        ensureAvailable();
125        proxy.log(logger, level, msg, t);
126    }
127
128    public static void log(Object logger, Object level, String msg, Object... params) {
129        ensureAvailable();
130        proxy.log(logger, level, msg, params);
131    }
132
133    public static Object parseLevel(String levelName) {
134        ensureAvailable();
135        return proxy.parseLevel(levelName);
136    }
137
138    public static String getLevelName(Object level) {
139        ensureAvailable();
140        return proxy.getLevelName(level);
141    }
142
143    public static int getLevelValue(Object level) {
144        ensureAvailable();
145        return proxy.getLevelValue(level);
146    }
147
148    private static final String DEFAULT_FORMAT =
149        "%1$tb %1$td, %1$tY %1$tl:%1$tM:%1$tS %1$Tp %2$s%n%4$s: %5$s%6$s%n";
150
151    private static final String FORMAT_PROP_KEY = "java.util.logging.SimpleFormatter.format";
152    public static String getSimpleFormat() {
153        return getSimpleFormat(true);
154    }
155
156    // useProxy if true will cause initialization of
157    // java.util.logging and read its configuration
158    static String getSimpleFormat(boolean useProxy) {
159        String format =
160            AccessController.doPrivileged(
161                new PrivilegedAction<String>() {
162                    public String run() {
163                        return System.getProperty(FORMAT_PROP_KEY);
164                    }
165                });
166
167        if (useProxy && proxy != null && format == null) {
168            format = proxy.getProperty(FORMAT_PROP_KEY);
169        }
170
171        if (format != null) {
172            try {
173                // validate the user-defined format string
174                String.format(format, new Date(), "", "", "", "", "");
175            } catch (IllegalArgumentException e) {
176                // illegal syntax; fall back to the default format
177                format = DEFAULT_FORMAT;
178            }
179        } else {
180            format = DEFAULT_FORMAT;
181        }
182        return format;
183    }
184
185}
186