Logger (Jasper Internal API Documentation)

org.apache.jasper.logging
Class Logger

java.lang.Object

  |

  +--org.apache.jasper.logging.Logger

Direct Known Subclasses:

DefaultLogger, JasperLogger

public abstract class Logger

extends java.lang.Object

Interface for a logging object. A logging object provides mechanism for logging errors and messages that are of interest to someone who is trying to monitor the system.

Since:

Tomcat 3.1

Author:

Anil Vijendran (akv@eng.sun.com), Alex Chaffee (alex@jguru.com)

Nested Class Summary

static class

Logger.Helper Wrapper for Logger.

Field Summary

protected boolean	custom
static int	DEBUG
protected static Logger	defaultLogger
protected static java.io.Writer	defaultSink
static int	ERROR
static int	FATAL Verbosity level codes.
static int	INFORMATION
protected static java.util.Hashtable	loggers
protected java.lang.String	name
protected java.io.Writer	sink
protected boolean	timestamp Should we timestamp this log at all?
protected java.lang.String	timestampFormat The timestamp format string, default is "yyyy-MM-dd hh:mm:ss"
protected java.text.DateFormat	timestampFormatter
protected boolean	timestampRaw true = The timestamp format is raw msec-since-epoch false = The timestamp format is a custom string to pass to SimpleDateFormat
static int	WARNING

Constructor Summary

Logger()

Method Summary

static boolean	canIgnore(java.lang.Throwable t) General purpose nasty hack to determine if an exception can be safely ignored -- specifically, if it's an IOException or SocketException that is thrown in the normal course of a socket closing halfway through a connection, or if it's a weird unknown type of exception.
void	close() Close the log.
abstract void	flush() Flush the log.
protected java.lang.String	formatTimestamp(long msec)
protected void	formatTimestamp(long msec, java.lang.StringBuffer buf)
static Logger	getDefaultLogger() Get the logger that prints to the default sink (usu.
static Logger	getLogger(java.lang.String name)
static java.util.Enumeration	getLoggerNames()
java.lang.String	getName() Get name of this log channel.
java.lang.String	getPath()
java.lang.String	getTimestampFormat()
int	getVerbosityLevel() Get the current verbosity level.
boolean	isOpen() Is this Log usable?
boolean	isTimestamp()
void	log(java.lang.String message) Prints the log message at the "default" log level: INFORMATION
void	log(java.lang.String message, int verbosityLevel) Prints the log message.
void	log(java.lang.String message, java.lang.Throwable t) Prints log message and stack trace, with verbosityLevel ERROR.
void	log(java.lang.String message, java.lang.Throwable t, int verbosityLevel) Prints log message and stack trace.
boolean	matchVerbosityLevel(int verbosityLevel)
void	open() Open the log - will create the log file and all the parent directories.
static void	putLogger(Logger logger)
protected abstract void	realLog(java.lang.String message) Subclasses implement these methods which are called by the log(..) methods internally.
protected abstract void	realLog(java.lang.String message, java.lang.Throwable t) Subclasses implement these methods which are called by the log(..) methods internally.
static void	removeLogger(Logger logger)
void	setCustomOutput(java.lang.String value)
static void	setDefaultSink(java.io.Writer w) Set the default output stream that is used by all logging channels.
void	setName(java.lang.String name) Set name of this log channel.
void	setPath(java.lang.String path) Set the path name for the log output file.
void	setTimestamp(java.lang.String value) Do we need to time stamp this or not?
void	setTimestampFormat(java.lang.String value) If we are timestamping at all, what format to use when printing the timestamp.
void	setVerbosityLevel(int level) Set the verbosity level for this logger.
void	setVerbosityLevel(java.lang.String level) Set the verbosity level for this logger.
static java.lang.String	throwableToString(java.lang.Throwable t) Converts a Throwable to a printable stack trace, including the nested root cause for a ServletException or JasperException if applicable TODO: JDBCException too
static java.lang.String	throwableToString(java.lang.Throwable t, java.lang.String rootcause) Converts a Throwable to a printable stack trace, including the nested root cause for a ServletException or JasperException or SQLException if applicable
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

FATAL

public static final int FATAL

Verbosity level codes.

See Also:

Constant Field Values

ERROR

public static final int ERROR

See Also:

Constant Field Values

WARNING

public static final int WARNING

See Also:

Constant Field Values

INFORMATION

public static final int INFORMATION

See Also:

Constant Field Values

DEBUG

public static final int DEBUG

See Also:

Constant Field Values

defaultSink

protected static java.io.Writer defaultSink

loggers

protected static java.util.Hashtable loggers

defaultLogger

protected static Logger defaultLogger

custom

protected boolean custom

sink

protected java.io.Writer sink

name

protected java.lang.String name

timestamp

protected boolean timestamp

Should we timestamp this log at all?

timestampRaw

protected boolean timestampRaw

true = The timestamp format is raw msec-since-epoch
false = The timestamp format is a custom string to pass to SimpleDateFormat

timestampFormat

protected java.lang.String timestampFormat

The timestamp format string, default is "yyyy-MM-dd hh:mm:ss"

timestampFormatter

protected java.text.DateFormat timestampFormatter

Constructor Detail

Logger

public Logger()

Method Detail

setDefaultSink

public static void setDefaultSink(java.io.Writer w)

Set the default output stream that is used by all logging channels.

Parameters:

w - the default output stream.

getLogger

public static Logger getLogger(java.lang.String name)

getDefaultLogger

public static Logger getDefaultLogger()

Get the logger that prints to the default sink (usu. System.err)

getLoggerNames

public static java.util.Enumeration getLoggerNames()

putLogger

public static void putLogger(Logger logger)

removeLogger

public static void removeLogger(Logger logger)

throwableToString

public static java.lang.String throwableToString(java.lang.Throwable t)

Converts a Throwable to a printable stack trace, including the nested root cause for a ServletException or JasperException if applicable TODO: JDBCException too

Parameters:

t - any Throwable, or ServletException, or null

throwableToString

public static java.lang.String throwableToString(java.lang.Throwable t,
                                                 java.lang.String rootcause)

Converts a Throwable to a printable stack trace, including the nested root cause for a ServletException or JasperException or SQLException if applicable

Parameters:

t - any Throwable, or ServletException, or null

rootcause - localized string equivalent of "Root Cause"

canIgnore

public static boolean canIgnore(java.lang.Throwable t)

General purpose nasty hack to determine if an exception can be safely ignored -- specifically, if it's an IOException or SocketException that is thrown in the normal course of a socket closing halfway through a connection, or if it's a weird unknown type of exception. This is an intractable problem, and this is a bad solution, but at least it's centralized.

isOpen

public boolean isOpen()

Is this Log usable?

log

public final void log(java.lang.String message)

Prints the log message at the "default" log level: INFORMATION

Parameters:

message - the message to log.

log

public final void log(java.lang.String message,
                      int verbosityLevel)

Prints the log message.

Parameters:

message - the message to log.

verbosityLevel - what type of message is this? (WARNING/DEBUG/INFO etc)

log

public final void log(java.lang.String message,
                      java.lang.Throwable t)

Prints log message and stack trace, with verbosityLevel ERROR. This makes the assumption that throwables are exceptions which are errors by nature; if you disagree, you can always call log(msg, t, Logger.INFORMATION) or whatever.

Parameters:

message - the message to log.

t - the exception that was thrown.

log

public final void log(java.lang.String message,
                      java.lang.Throwable t,
                      int verbosityLevel)

Prints log message and stack trace.

Parameters:

message - the message to log.

t - the exception that was thrown.

verbosityLevel - what type of message is this? (WARNING/DEBUG/INFO etc)

matchVerbosityLevel

public boolean matchVerbosityLevel(int verbosityLevel)

realLog

protected abstract void realLog(java.lang.String message)

Subclasses implement these methods which are called by the log(..) methods internally.

Parameters:

message - the message to log.

realLog

protected abstract void realLog(java.lang.String message,
                                java.lang.Throwable t)

Subclasses implement these methods which are called by the log(..) methods internally.

Parameters:

message - the message to log.

t - the exception that was thrown.

flush

public abstract void flush()

Flush the log.

close

public void close()

Close the log.

getName

public java.lang.String getName()

Get name of this log channel.

setName

public void setName(java.lang.String name)

Set name of this log channel.

Parameters:

name - Name of this logger.

setPath

public void setPath(java.lang.String path)

Set the path name for the log output file.

Parameters:

path - The path to the log file.

getPath

public java.lang.String getPath()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

open

public void open()

Open the log - will create the log file and all the parent directories. You must open the logger before use, or it will write to System.err

setVerbosityLevel

public void setVerbosityLevel(java.lang.String level)

Set the verbosity level for this logger. This controls how the logs will be filtered.

Parameters:

level - one of the verbosity level strings.

setVerbosityLevel

public void setVerbosityLevel(int level)

Set the verbosity level for this logger. This controls how the logs will be filtered.

Parameters:

level - one of the verbosity level codes.

getVerbosityLevel

public int getVerbosityLevel()

Get the current verbosity level.

setTimestamp

public void setTimestamp(java.lang.String value)

Do we need to time stamp this or not?

Parameters:

value - "yes/no" or "true/false"

isTimestamp

public boolean isTimestamp()

setTimestampFormat

public void setTimestampFormat(java.lang.String value)

If we are timestamping at all, what format to use when printing the timestamp. Default = "yyyy-MM-dd hh:mm:ss". Special case: "msec" => raw number of msec since epoch, very efficient but not user-friendly

See Also:

SimpleDateFormat

getTimestampFormat

public java.lang.String getTimestampFormat()

setCustomOutput

public void setCustomOutput(java.lang.String value)

formatTimestamp

protected java.lang.String formatTimestamp(long msec)

formatTimestamp

protected void formatTimestamp(long msec,
                               java.lang.StringBuffer buf)