org.jfree.util

Class Log

public class Log extends Object

A simple logging facility. Create a class implementing the LogTarget interface to use this feature.

Author: Thomas Morgner

Nested Class Summary
static classLog.SimpleMessage
A simple message class.
Constructor Summary
protected Log()
Creates a new Log instance.
Method Summary
voidaddTarget(LogTarget target)
Adds a log target to this facility.
static LogContextcreateContext(Class context)
Creates a log context.
static LogContextcreateContext(String context)
Creates a log context.
static voiddebug(Object message)
A convenience method for logging a 'debug' message.
static voiddebug(Object message, Exception e)
A convenience method for logging a 'debug' message.
protected static voiddefineLog(Log log)
Redefines or clears the currently used log instance.
protected voiddoLog(int level, Object message)
Logs a message to the main log stream.
protected voiddoLog(int level, Object message, Exception e)
Logs a message to the main log stream.
static voiderror(Object message)
A convenience method for logging an 'error' message.
static voiderror(Object message, Exception e)
A convenience method for logging an 'error' message.
intgetDebuglevel()
Returns the currently defined debug level.
static LoggetInstance()
Returns the singleton Log instance.
LogTarget[]getTargets()
Returns the registered logtargets.
static voidinfo(Object message)
A convenience method for logging an 'info' message.
static voidinfo(Object message, Exception e)
A convenience method for logging an 'info' message.
voidinit()
Initializes the logging system.
protected LogContextinternalCreateContext(String context)
Creates a log context.
static booleanisDebugEnabled()
Returns true, if the log level allows debug messages to be printed.
static booleanisErrorEnabled()
Returns true, if the log level allows error messages to be printed.
static booleanisInfoEnabled()
Returns true, if the log level allows informational messages to be printed.
static booleanisWarningEnabled()
Returns true, if the log level allows warning messages to be printed.
static voidlog(int level, Object message)
Logs a message to the main log stream.
static voidlog(int level, Object message, Exception e)
Logs a message to the main log stream.
voidremoveTarget(LogTarget target)
Removes a log target from this facility.
voidreplaceTargets(LogTarget target)
Replaces all log targets by the given target.
protected voidsetDebuglevel(int debuglevel)
Defines the debug level for the log system.
static voidwarn(Object message)
A convenience method for logging a 'warning' message.
static voidwarn(Object message, Exception e)
A convenience method for logging a 'warning' message.

Constructor Detail

Log

protected Log()
Creates a new Log instance. The Log is used to manage the log targets.

Method Detail

addTarget

public void addTarget(LogTarget target)
Adds a log target to this facility. Log targets get informed, via the LogTarget interface, whenever a message is logged with this class.

Parameters: target the target.

createContext

public static LogContext createContext(Class context)
Creates a log context.

Parameters: context the class (null not permitted).

Returns: A log context.

createContext

public static LogContext createContext(String context)
Creates a log context.

Parameters: context the label for the context.

Returns: A log context.

debug

public static void debug(Object message)
A convenience method for logging a 'debug' message.

Parameters: message the message.

debug

public static void debug(Object message, Exception e)
A convenience method for logging a 'debug' message.

Parameters: message the message. e the exception.

defineLog

protected static void defineLog(Log log)
Redefines or clears the currently used log instance.

Parameters: log the new log instance or null, to return to the default implementation.

doLog

protected void doLog(int level, Object message)
Logs a message to the main log stream. All attached log targets will also receive this message. If the given log-level is higher than the given debug-level in the main config file, no logging will be done.

Parameters: level log level of the message. message text to be logged.

doLog

protected void doLog(int level, Object message, Exception e)
Logs a message to the main log stream. All attached logTargets will also receive this message. If the given log-level is higher than the given debug-level in the main config file, no logging will be done.

The exception's stacktrace will be appended to the log-stream

Parameters: level log level of the message. message text to be logged. e the exception, which should be logged.

error

public static void error(Object message)
A convenience method for logging an 'error' message.

Parameters: message the message.

error

public static void error(Object message, Exception e)
A convenience method for logging an 'error' message.

Parameters: message the message. e the exception.

getDebuglevel

public int getDebuglevel()
Returns the currently defined debug level. The higher the level, the more details are printed.

Returns: the debug level.

getInstance

public static Log getInstance()
Returns the singleton Log instance. A new instance is created if necessary.

Returns: the singleton instance.

getTargets

public LogTarget[] getTargets()
Returns the registered logtargets.

Returns: the logtargets.

info

public static void info(Object message)
A convenience method for logging an 'info' message.

Parameters: message the message.

info

public static void info(Object message, Exception e)
A convenience method for logging an 'info' message.

Parameters: message the message. e the exception.

init

public void init()
Initializes the logging system. Implementors should override this method to supply their own log configuration.

internalCreateContext

protected LogContext internalCreateContext(String context)
Creates a log context.

Parameters: context the name of the logging context (a common prefix).

Returns: A log context.

isDebugEnabled

public static boolean isDebugEnabled()
Returns true, if the log level allows debug messages to be printed.

Returns: true, if messages with an log level of DEBUG are allowed.

isErrorEnabled

public static boolean isErrorEnabled()
Returns true, if the log level allows error messages to be printed.

Returns: true, if messages with an log level of ERROR are allowed.

isInfoEnabled

public static boolean isInfoEnabled()
Returns true, if the log level allows informational messages to be printed.

Returns: true, if messages with an log level of INFO are allowed.

isWarningEnabled

public static boolean isWarningEnabled()
Returns true, if the log level allows warning messages to be printed.

Returns: true, if messages with an log level of WARN are allowed.

log

public static void log(int level, Object message)
Logs a message to the main log stream. All attached log targets will also receive this message. If the given log-level is higher than the given debug-level in the main config file, no logging will be done.

Parameters: level log level of the message. message text to be logged.

log

public static void log(int level, Object message, Exception e)
Logs a message to the main log stream. All attached logTargets will also receive this message. If the given log-level is higher than the given debug-level in the main config file, no logging will be done.

The exception's stacktrace will be appended to the log-stream

Parameters: level log level of the message. message text to be logged. e the exception, which should be logged.

removeTarget

public void removeTarget(LogTarget target)
Removes a log target from this facility.

Parameters: target the target to remove.

replaceTargets

public void replaceTargets(LogTarget target)
Replaces all log targets by the given target.

Parameters: target the new and only logtarget.

setDebuglevel

protected void setDebuglevel(int debuglevel)
Defines the debug level for the log system.

Parameters: debuglevel the new debug level

See Also: getDebuglevel

warn

public static void warn(Object message)
A convenience method for logging a 'warning' message.

Parameters: message the message.

warn

public static void warn(Object message, Exception e)
A convenience method for logging a 'warning' message.

Parameters: message the message. e the exception.