/*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Group.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.tomcat.logging;
import java.io.Writer;
import java.io.StringWriter;
import java.io.PrintWriter;
import java.util.Date;
import javax.servlet.ServletException;
import org.apache.tomcat.util.Queue;
/**
* A real implementation of the Logger abstraction.
*
* @author Anil V (akv@eng.sun.com)
* @since Tomcat 3.1
*/
public class TomcatLogger extends Logger {
/**
* Converts a Throwable to a printable stack trace, including the
* nested root cause for a ServletException if applicable
*
* @param t any Throwable, or ServletException, or null
**/
public static String throwableToString( Throwable t ) {
StringWriter sw = new StringWriter();
PrintWriter w = new PrintWriter(sw);
if (t != null) {
t.printStackTrace(w);
if (t instanceof ServletException) {
Throwable cause = ((ServletException)t).getRootCause();
if (cause != null) {
// we could use a StringManager here to get the
// localized translation of "Root cause" , but
// since it's going into a log, no user will see
// it, and it's desirable that the log file is
// predictable, so just use English
String rootmsg = "Root cause:";
w.println(rootmsg);
cause.printStackTrace(w);
}
}
}
w.flush(); // couldn't hurt...
return sw.toString();
}
/**
* This is an entry that is created in response to every
* Logger.log(...) call.
*/
class LogEntry {
String logName;
long date;
String message;
Throwable t;
LogEntry(String message, Throwable t) {
// avoid expensive system call
if (TomcatLogger.this.timestamp)
this.date = System.currentTimeMillis();
this.message = message;
this.t = t;
}
/**
* Get the writer into which this log entry needs to be
* written into.
*/
Writer getWriter() {
return TomcatLogger.this.sink;
}
/**
* Format the log message nicely into a string.
*/
public String toString() {
StringBuffer val = new StringBuffer();
// custom output, now with timestamp
// does anyone actually use non-custom logs?
if( !TomcatLogger.this.custom ) {
val.append("<");
val.append(TomcatLogger.this.getName());
val.append("> ");
}
if (TomcatLogger.this.timestamp) {
formatTimestamp( date, val );
val.append(" - ");
}
if (message != null) {
val.append(message);
}
if (t != null) {
val.append(" - ");
val.append(throwableToString( t ));
}
if( !TomcatLogger.this.custom ) {
val.append("</");
val.append(TomcatLogger.this.getName());
val.append("> ");
}
return val.toString();
}
}
/**
* Just one daemon and one queue for all Logger instances..
*/
static LogDaemon logDaemon = null;
static Queue logQueue = null;
public TomcatLogger() {
if (logDaemon == null || logQueue == null) {
logQueue = new Queue();
logDaemon = new LogDaemon(logQueue);
logDaemon.start();
}
}
/**
* Adds a log message to the queue and returns immediately. The
* logger daemon thread will pick it up later and actually print
* it out.
*
* @param message the message to log.
*/
protected void realLog(String message) {
logQueue.put(new LogEntry(message, null));
}
/**
* Adds a log message and stack trace to the queue and returns
* immediately. The logger daemon thread will pick it up later and
* actually print it out.
*
* @param message the message to log.
* @param t the exception that was thrown.
*/
protected void realLog(String message, Throwable t) {
logQueue.put(new LogEntry(message, t));
}
/**
* Flush the log.
*/
public void flush() {
logDaemon.flush();
}
}
/**
* The daemon thread that looks in a queue and if it is not empty
* writes out everything in the queue to the sink.
*/
class LogDaemon extends Thread {
LogDaemon(Queue logQueue) {
this.logQueue = logQueue;
setDaemon(true);
}
static char[] newline;
static {
String separator = System.getProperty("line.separator", "\n");
newline = separator.toCharArray();
}
Runnable flusher = new Runnable() {
public void run() {
do {
TomcatLogger.LogEntry logEntry =
(TomcatLogger.LogEntry) LogDaemon.this.logQueue.pull();
Writer writer = logEntry.getWriter();
if (writer != null)
try {
writer.write(logEntry.toString());
writer.write(newline);
writer.flush();
} catch (Exception ex) { // IOException
ex.printStackTrace();
}
} while (!LogDaemon.this.logQueue.isEmpty());
}
};
public void run() {
while (true)
flusher.run();
}
public void flush() {
Thread workerThread = new Thread(flusher);
workerThread.start();
}
private Queue logQueue;
}