ConsoleHandler.java revision 49965c1dc9da104344f4893a05e45795a5740d20 
1/*
2 * Copyright (c) 2000, 2003, 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 java.util.logging;
28
29import java.io.*;
30import java.net.*;
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.  If properties are not defined
39 * (or have invalid values) then the specified default values are used.
40 * <ul>
41 * <li>   java.util.logging.ConsoleHandler.level
42 *        specifies the default level for the <tt>Handler</tt>
43 *        (defaults to <tt>Level.INFO</tt>).
44 * <li>   java.util.logging.ConsoleHandler.filter
45 *        specifies the name of a <tt>Filter</tt> class to use
46 *        (defaults to no <tt>Filter</tt>).
47 * <li>   java.util.logging.ConsoleHandler.formatter
48 *        specifies the name of a <tt>Formatter</tt> class to use
49 *        (defaults to <tt>java.util.logging.SimpleFormatter</tt>).
50 * <li>   java.util.logging.ConsoleHandler.encoding
51 *        the name of the character set encoding to use (defaults to
52 *        the default platform encoding).
53 * </ul>
54 * <p>
55 * @since 1.4
56 */
57
58public class ConsoleHandler extends StreamHandler {
59    // Private method to configure a ConsoleHandler from LogManager
60    // properties and/or default values as specified in the class
61    // javadoc.
62    private void configure() {
63        LogManager manager = LogManager.getLogManager();
64        String cname = getClass().getName();
65
66        setLevel(manager.getLevelProperty(cname +".level", Level.INFO));
67        setFilter(manager.getFilterProperty(cname +".filter", null));
68        setFormatter(manager.getFormatterProperty(cname +".formatter", new SimpleFormatter()));
69        try {
70            setEncoding(manager.getStringProperty(cname +".encoding", null));
71        } catch (Exception ex) {
72            try {
73                setEncoding(null);
74            } catch (Exception ex2) {
75                // doing a setEncoding with null should always work.
76                // assert false;
77            }
78        }
79    }
80
81    /**
82     * Create a <tt>ConsoleHandler</tt> for <tt>System.err</tt>.
83     * <p>
84     * The <tt>ConsoleHandler</tt> is configured based on
85     * <tt>LogManager</tt> properties (or their default values).
86     *
87     */
88    public ConsoleHandler() {
89        sealed = false;
90        configure();
91        setOutputStream(System.err);
92        sealed = true;
93    }
94
95    /**
96     * Publish a <tt>LogRecord</tt>.
97     * <p>
98     * The logging request was made initially to a <tt>Logger</tt> object,
99     * which initialized the <tt>LogRecord</tt> and forwarded it here.
100     * <p>
101     * @param  record  description of the log event. A null record is
102     *                 silently ignored and is not published
103     */
104    public void publish(LogRecord record) {
105        super.publish(record);
106        flush();
107    }
108
109    /**
110     * Override <tt>StreamHandler.close</tt> to do a flush but not
111     * to close the output stream.  That is, we do <b>not</b>
112     * close <tt>System.err</tt>.
113     */
114    public void close() {
115        flush();
116    }
117}
118