001    /* ConsoleHandler.java -- a class for publishing log messages to System.err
002       Copyright (C) 2002, 2004 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package java.util.logging;
040    
041    /**
042     * A <code>ConsoleHandler</code> publishes log records to
043     * <code>System.err</code>.
044     *
045     * <p><strong>Configuration:</strong> Values of the subsequent
046     * <code>LogManager</code> properties are taken into consideration
047     * when a <code>ConsoleHandler</code> is initialized.
048     * If a property is not defined, or if it has an invalid
049     * value, a default is taken without an exception being thrown.
050     *
051     * <ul>
052     *
053     * <li><code>java.util.logging.ConsoleHandler.level</code> - specifies
054     *     the initial severity level threshold. Default value:
055     *     <code>Level.INFO</code>.</li>
056     *
057     * <li><code>java.util.logging.ConsoleHandler.filter</code> - specifies
058     *     the name of a Filter class. Default value: No Filter.</li>
059     *
060     * <li><code>java.util.logging.ConsoleHandler.formatter</code> - specifies
061     *     the name of a Formatter class. Default value:
062     *     <code>java.util.logging.SimpleFormatter</code>.</li>
063     *
064     * <li><code>java.util.logging.ConsoleHandler.encoding</code> - specifies
065     *     the name of the character encoding. Default value:
066     *     the default platform encoding.</li>
067     *
068     * </ul>
069     *
070     * @author Sascha Brawer (brawer@acm.org)
071     */
072    public class ConsoleHandler
073      extends StreamHandler
074    {
075      /**
076       * Constructs a <code>StreamHandler</code> that publishes
077       * log records to <code>System.err</code>.  The initial
078       * configuration is determined by the <code>LogManager</code>
079       * properties described above.
080       */
081      public ConsoleHandler()
082      {
083        super(System.err, "java.util.logging.ConsoleHandler", Level.INFO,
084             /* formatter */ null, SimpleFormatter.class);
085      }
086    
087    
088      /**
089       * Forces any data that may have been buffered to the underlying
090       * output device, but does <i>not</i> close <code>System.err</code>.
091       *
092       * <p>In case of an I/O failure, the <code>ErrorManager</code>
093       * of this <code>ConsoleHandler</code> will be informed, but the caller
094       * of this method will not receive an exception.
095       */
096      public void close()
097      {
098        flush();
099      }
100    
101    
102      /**
103       * Publishes a <code>LogRecord</code> to the console, provided the
104       * record passes all tests for being loggable.
105       *
106       * <p>Most applications do not need to call this method directly.
107       * Instead, they will use use a <code>Logger</code>, which will
108       * create LogRecords and distribute them to registered handlers.
109       *
110       * <p>In case of an I/O failure, the <code>ErrorManager</code>
111       * of this <code>SocketHandler</code> will be informed, but the caller
112       * of this method will not receive an exception.
113       *
114       * <p>The GNU implementation of <code>ConsoleHandler.publish</code>
115       * calls flush() for every request to publish a record, so
116       * they appear immediately on the console.
117       *
118       * @param record the log event to be published.
119       */
120      public void publish(LogRecord record)
121      {
122        super.publish(record);
123        flush();
124      }
125    }