X-Git-Url: http://source.jalview.org/gitweb/?a=blobdiff_plain;f=srcjar%2Forg%2Fapache%2Flog4j%2Fnet%2FTelnetAppender.java;fp=srcjar%2Forg%2Fapache%2Flog4j%2Fnet%2FTelnetAppender.java;h=5b49a2c92dc53894edc276df79247813a8338f26;hb=2d6292c0377bc6b773c6844a45d3f2c5fac352c7;hp=0000000000000000000000000000000000000000;hpb=954af328a2a6a0055572cd1a09ee035301222574;p=jalview.git diff --git a/srcjar/org/apache/log4j/net/TelnetAppender.java b/srcjar/org/apache/log4j/net/TelnetAppender.java new file mode 100644 index 0000000..5b49a2c --- /dev/null +++ b/srcjar/org/apache/log4j/net/TelnetAppender.java @@ -0,0 +1,237 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.log4j.net; + +import org.apache.log4j.AppenderSkeleton; +import org.apache.log4j.helpers.LogLog; +import org.apache.log4j.spi.LoggingEvent; + +import java.io.IOException; +import java.io.PrintWriter; +import java.io.InterruptedIOException; +import java.net.ServerSocket; +import java.net.Socket; +import java.util.Enumeration; +import java.util.Iterator; +import java.util.Vector; + +/** +

The TelnetAppender is a log4j appender that specializes in + writing to a read-only socket. The output is provided in a + telnet-friendly way so that a log can be monitored over TCP/IP. + Clients using telnet connect to the socket and receive log data. + This is handy for remote monitoring, especially when monitoring a + servlet. + +

Here is a list of the available configuration options: + + + + + + + + + + + + + + +
NameRequirementDescriptionSample Value
PortoptionalThis parameter determines the port to use for announcing log events. The default port is 23 (telnet).5875
+ + @author Jay Funnell +*/ + +public class TelnetAppender extends AppenderSkeleton { + + private static final String EOL = "\r\n"; + private SocketHandler sh; + private int port = 23; + + /** + This appender requires a layout to format the text to the + attached client(s). */ + public boolean requiresLayout() { + return true; + } + + /** all of the options have been set, create the socket handler and + wait for connections. */ + public void activateOptions() { + try { + sh = new SocketHandler(port); + sh.start(); + } + catch(InterruptedIOException e) { + Thread.currentThread().interrupt(); + e.printStackTrace(); + } catch(IOException e) { + e.printStackTrace(); + } catch(RuntimeException e) { + e.printStackTrace(); + } + super.activateOptions(); + } + + public + int getPort() { + return port; + } + + public + void setPort(int port) { + this.port = port; + } + + + /** shuts down the appender. */ + public void close() { + if (sh != null) { + sh.close(); + try { + sh.join(); + } catch(InterruptedException ex) { + Thread.currentThread().interrupt(); + } + } + } + + /** Handles a log event. For this appender, that means writing the + message to each connected client. */ + protected void append(LoggingEvent event) { + if(sh != null) { + sh.send(layout.format(event)); + if(layout.ignoresThrowable()) { + String[] s = event.getThrowableStrRep(); + if (s != null) { + StringBuffer buf = new StringBuffer(); + for(int i = 0; i < s.length; i++) { + buf.append(s[i]); + buf.append(EOL); + } + sh.send(buf.toString()); + } + } + } + } + + //---------------------------------------------------------- SocketHandler: + + /** The SocketHandler class is used to accept connections from + clients. It is threaded so that clients can connect/disconnect + asynchronously. */ + protected class SocketHandler extends Thread { + + private Vector writers = new Vector(); + private Vector connections = new Vector(); + private ServerSocket serverSocket; + private int MAX_CONNECTIONS = 20; + + public void finalize() { + close(); + } + + /** + * make sure we close all network connections when this handler is destroyed. + * @since 1.2.15 + */ + public void close() { + synchronized(this) { + for(Enumeration e = connections.elements();e.hasMoreElements();) { + try { + ((Socket)e.nextElement()).close(); + } catch(InterruptedIOException ex) { + Thread.currentThread().interrupt(); + } catch(IOException ex) { + } catch(RuntimeException ex) { + } + } + } + + try { + serverSocket.close(); + } catch(InterruptedIOException ex) { + Thread.currentThread().interrupt(); + } catch(IOException ex) { + } catch(RuntimeException ex) { + } + } + + /** sends a message to each of the clients in telnet-friendly output. */ + public synchronized void send(final String message) { + Iterator ce = connections.iterator(); + for(Iterator e = writers.iterator();e.hasNext();) { + ce.next(); + PrintWriter writer = (PrintWriter)e.next(); + writer.print(message); + if(writer.checkError()) { + ce.remove(); + e.remove(); + } + } + } + + /** + Continually accepts client connections. Client connections + are refused when MAX_CONNECTIONS is reached. + */ + public void run() { + while(!serverSocket.isClosed()) { + try { + Socket newClient = serverSocket.accept(); + PrintWriter pw = new PrintWriter(newClient.getOutputStream()); + if(connections.size() < MAX_CONNECTIONS) { + synchronized(this) { + connections.addElement(newClient); + writers.addElement(pw); + pw.print("TelnetAppender v1.0 (" + connections.size() + + " active connections)" + EOL + EOL); + pw.flush(); + } + } else { + pw.print("Too many connections." + EOL); + pw.flush(); + newClient.close(); + } + } catch(Exception e) { + if (e instanceof InterruptedIOException || e instanceof InterruptedException) { + Thread.currentThread().interrupt(); + } + if (!serverSocket.isClosed()) { + LogLog.error("Encountered error while in SocketHandler loop.", e); + } + break; + } + } + + try { + serverSocket.close(); + } catch(InterruptedIOException ex) { + Thread.currentThread().interrupt(); + } catch(IOException ex) { + } + } + + public SocketHandler(int port) throws IOException { + serverSocket = new ServerSocket(port); + setName("TelnetAppender-" + getName() + "-" + port); + } + + } +}