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Log.java API Doc Glassfish v2 API 10942 Fri May 04 22:33:16 BST 2007 org.apache.tomcat.util.log

Log

java.lang.Object

public class Log extends Object implements com.sun.org.apache.commons.logging.Log

This is the main class seen by objects that need to log. It has a log channel to write to; if it can't find a log with that name, it outputs to the default sink. Also prepends a descriptive name to each message (usually the toString() of the calling object), so it's easier to identify the source.

Intended for use by client classes to make it easy to do reliable, consistent logging behavior, even if you don't necessarily have a context, or if you haven't registered any log files yet, or if you're in a non-Tomcat application.

Usage:

class Foo {
Log log = Log.getLog("tc_log", "Foo"); // or...
Log log = Log.getLog("tc_log", this); // fills in "Foo" for you
...
log.log("Something happened");
...
log.log("Starting something", Log.DEBUG);
...
catch (IOException e) {
log.log("While doing something", e);
}

As a special feature ( required in tomcat operation ) the Log can be modified at run-time, by changing and configuring the logging implementation ( without requiring any special change in the user code ). That means that the user can do a Log.getLog() at any time, even before the logging system is fully configured. The embeding application can then set up or change the logging details, without any action from the log user.

deprecated: Commons-logging should be used instead.
author: Alex Chaffee [alex@jguru.com]
author: Costin Manolache

Fields Summary
public static final int
FATAL
Verbosity level codes.
public static final int
ERROR
public static final int
WARNING
public static final int
INFORMATION
public static final int
DEBUG
protected final String
logname
protected final String
prefix
private LogHandler
proxy
private static LogManager
logManager
Constructors Summary
protected Log(String channel, String prefix, LogHandler proxy, Object owner)
// -------------------- Various constructors -------------------- this.logname=channel; this.prefix=prefix; this.proxy=proxy;
Methods Summary
public void close()
proxy.close();
public void debug(java.lang.Object message)
log(message.toString(), null, DEBUG);
public void debug(java.lang.Object message, java.lang.Throwable exception)
log(message.toString(), exception, DEBUG);
public void error(java.lang.Object message)
log(message.toString(), null, ERROR);
public void error(java.lang.Object message, java.lang.Throwable exception)
log(message.toString(), exception, ERROR);
public void fatal(java.lang.Object message)
log(message.toString(), null, FATAL);
public void fatal(java.lang.Object message, java.lang.Throwable exception)
log(message.toString(), exception, FATAL);
public void flush()
Flush any buffers. Override if needed.
proxy.flush();
public java.lang.String getChannel(LogManager lm)
if( lm != logManager ) return null; return logname;
public int getLevel()
The configured logging level for this channel
return proxy.getLevel();
public static org.apache.tomcat.util.log.Log getLog(java.lang.String channel, java.lang.String prefix)
param
logname name of log to use
param
owner object whose class name to use as prefix
return logManager.getLog( channel, prefix, null );
public static org.apache.tomcat.util.log.Log getLog(java.lang.String channel, java.lang.Object owner)
param
logname name of log to use
param
prefix string to prepend to each message
return logManager.getLog( channel, null, owner );
public void info(java.lang.Object message)
log(message.toString(), null, INFORMATION);
public void info(java.lang.Object message, java.lang.Throwable exception)
log(message.toString(), exception, INFORMATION);
public boolean isDebugEnabled()
return proxy.getLevel() <= DEBUG;
public boolean isErrorEnabled()
return proxy.getLevel() <= ERROR;
public boolean isFatalEnabled()
return proxy.getLevel() <= FATAL;
public boolean isInfoEnabled()
return proxy.getLevel() <= INFORMATION;
public boolean isTraceEnabled()
return proxy.getLevel() <= DEBUG;
public boolean isWarnEnabled()
return proxy.getLevel() <= WARNING;
public void log(java.lang.String msg)
Logs the message with level INFORMATION
log(msg, null, INFORMATION);
public void log(java.lang.String msg, java.lang.Throwable t)
Logs the Throwable with level ERROR (assumes an exception is trouble; if it's not, use log(msg, t, level))
log(msg, t, ERROR);
public void log(java.lang.String msg, int level)
Logs the message with given level
log(msg, null, level);
public void log(java.lang.String msg, java.lang.Throwable t, int level)
Logs the message and Throwable to its logger or, if logger not found, to the default logger, which writes to the default sink, which is usually System.err
log( prefix, msg, t, level );
public void log(java.lang.String prefix, java.lang.String msg, java.lang.Throwable t, int level)
proxy.log( prefix, msg, t, level );
public static synchronized LogManager setLogManager(LogManager lm)
Used by the embeding application ( tomcat ) to manage the logging. Initially, the Log is not managed, and the default manager is used. The application can find what loggers have been created from the default LogManager, and provide a special manager implemetation.
// can be changed only once - so that user // code can't change the log manager in running servers if( logManager.getClass() == LogManager.class ) { LogManager oldLM=logManager; logManager=lm; return oldLM; } return null;
public synchronized void setProxy(LogManager lm, LogHandler l)
// only the manager can change the proxy if( lm!= logManager ) { log("Attempt to change proxy " + lm + " " + logManager); return; } proxy=l;
public void trace(java.lang.Object message)
log(message.toString(), null, DEBUG);
public void trace(java.lang.Object message, java.lang.Throwable exception)
log(message.toString(), exception, DEBUG);
public void warn(java.lang.Object message)
log(message.toString(), null, WARNING);
public void warn(java.lang.Object message, java.lang.Throwable exception)
log(message.toString(), exception, WARNING);