2 * Jalview - A Sequence Alignment Editor and Viewer ($$Version-Rel$$)
3 * Copyright (C) $$Year-Rel$$ The Jalview Authors
5 * This file is part of Jalview.
7 * Jalview is free software: you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation, either version 3
10 * of the License, or (at your option) any later version.
12 * Jalview is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR
15 * PURPOSE. See the GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with Jalview. If not, see <http://www.gnu.org/licenses/>.
19 * The Jalview Authors are detailed in the 'AUTHORS' file.
23 import java.io.Serializable;
24 import java.nio.charset.StandardCharsets;
26 import javax.swing.JTextArea;
27 import javax.swing.SwingUtilities;
29 import org.apache.logging.log4j.core.Filter;
30 import org.apache.logging.log4j.core.Layout;
31 import org.apache.logging.log4j.core.LogEvent;
32 import org.apache.logging.log4j.core.appender.AbstractAppender;
33 import org.apache.logging.log4j.core.layout.PatternLayout;
36 * From http://textareaappender.zcage.com/ the means to capture the logs, too.
37 * Simple example of creating a Log4j appender that will write to a JTextArea.
39 public class JalviewAppender extends AbstractAppender
42 private final static Layout simpleLayout;
46 // SimpleLayout pattern found from
47 // https://logging.apache.org/log4j/log4j-2.12.4/manual/migration.html
48 simpleLayout = PatternLayout.newBuilder().withPattern("%level - %m%n")
52 protected JalviewAppender()
54 this("JalviewAppender", null, simpleLayout);
57 protected JalviewAppender(String name, Filter filter,
58 Layout<? extends Serializable> layout)
60 super(name, filter, layout);
61 // TODO Auto-generated constructor stub
64 static private JTextArea jTextArea = null;
66 /** Set the target JTextArea for the logging information to appear. */
67 static public void setTextArea(JTextArea jTextArea)
69 JalviewAppender.jTextArea = jTextArea;
73 * Format and then append the loggingEvent to the stored JTextArea.
75 public void append(LogEvent logEvent)
77 final String message = new String(simpleLayout.toByteArray(logEvent),
78 StandardCharsets.UTF_8);
80 // Append formatted message to textarea using the Swing Thread.
81 SwingUtilities.invokeLater(new Runnable()
85 if (jTextArea != null)
87 jTextArea.append(message);