1 /*
2 * Copyright (c) 2000, 2012, 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
27 package java.util.logging;
28
29 import java.security.AccessController;
30 import java.security.PrivilegedAction;
31
32 /**
33 * This <tt>Handler</tt> publishes log records to <tt>System.err</tt>.
34 * By default the <tt>SimpleFormatter</tt> is used to generate brief summaries.
35 * <p>
36 * <b>Configuration:</b>
37 * By default each <tt>ConsoleHandler</tt> is initialized using the following
38 * <tt>LogManager</tt> configuration properties where {@code <handler-name>}
39 * refers to the fully-qualified class name of the handler.
40 * If properties are not defined
41 * (or have invalid values) then the specified default values are used.
42 * <ul>
43 * <li> <handler-name>.level
44 * specifies the default level for the <tt>Handler</tt>
45 * (defaults to <tt>Level.INFO</tt>). </li>
46 * <li> <handler-name>.filter
47 * specifies the name of a <tt>Filter</tt> class to use
48 * (defaults to no <tt>Filter</tt>). </li>
49 * <li> <handler-name>.formatter
50 * specifies the name of a <tt>Formatter</tt> class to use
51 * (defaults to <tt>java.util.logging.SimpleFormatter</tt>). </li>
52 * <li> <handler-name>.encoding
53 * the name of the character set encoding to use (defaults to
54 * the default platform encoding). </li>
55 * </ul>
56 * <p>
57 * For example, the properties for {@code ConsoleHandler} would be:
58 * <ul>
59 * <li> java.util.logging.ConsoleHandler.level=INFO </li>
60 * <li> java.util.logging.ConsoleHandler.formatter=java.util.logging.SimpleFormatter </li>
61 * </ul>
62 * <p>
63 * For a custom handler, e.g. com.foo.MyHandler, the properties would be:
64 * <ul>
65 * <li> com.foo.MyHandler.level=INFO </li>
66 * <li> com.foo.MyHandler.formatter=java.util.logging.SimpleFormatter </li>
67 * </ul>
68 * <p>
69 * @since 1.4
70 */
71 public class ConsoleHandler extends StreamHandler {
72 // Private PrivilegedAction to configure a ConsoleHandler from LogManager
73 // properties and/or default values as specified in the class
74 // javadoc.
75 private class ConfigureAction implements PrivilegedAction<Void> {
76 @Override
77 public Void run() {
78 LogManager manager = LogManager.getLogManager();
79 String cname = ConsoleHandler.this.getClass().getName();
80
81 setLevel(manager.getLevelProperty(cname +".level", Level.INFO));
82 setFilter(manager.getFilterProperty(cname +".filter", null));
83 setFormatter(manager.getFormatterProperty(cname +".formatter", new SimpleFormatter()));
84 try {
85 setEncoding(manager.getStringProperty(cname +".encoding", null));
86 } catch (Exception ex) {
87 try {
88 setEncoding(null);
89 } catch (Exception ex2) {
90 // doing a setEncoding with null should always work.
91 // assert false;
92 }
93 }
94 setOutputStream(System.err);
95 return null;
96 }
97 }
98
99 /**
100 * Create a <tt>ConsoleHandler</tt> for <tt>System.err</tt>.
101 * <p>
102 * The <tt>ConsoleHandler</tt> is configured based on
103 * <tt>LogManager</tt> properties (or their default values).
104 *
105 */
106 public ConsoleHandler() {
107 AccessController.doPrivileged(new ConfigureAction(),
108 null, LogManager.controlPermission);
109 }
110
111 /**
112 * Publish a <tt>LogRecord</tt>.
113 * <p>
114 * The logging request was made initially to a <tt>Logger</tt> object,
115 * which initialized the <tt>LogRecord</tt> and forwarded it here.
116 * <p>
117 * @param record description of the log event. A null record is
118 * silently ignored and is not published
119 */
120 @Override
121 public void publish(LogRecord record) {
122 super.publish(record);
123 flush();
124 }
125
126 /**
127 * Override <tt>StreamHandler.close</tt> to do a flush but not
128 * to close the output stream. That is, we do <b>not</b>
129 * close <tt>System.err</tt>.
130 */
131 @Override
132 public void close() {
133 flush();
134 }
135 }