Package org.apache.sis.util.logging
Class Logging
A set of utilities method for configuring loggings in SIS. Library implementers should fetch
their loggers using the
getLogger(String)
static method defined in this Logging
class rather than the one defined in the standard Logger
class, in order to give SIS a
chance to redirect the logs to an other framework like
Commons-logging or
Log4J.
This class provides also some convenience static methods, including:
log(Class, String, LogRecord)
for setting the logger name, source class name and source method name of the given record before to log it.unexpectedException(Logger, Class, String, Throwable)
for reporting an anomalous but nevertheless non-fatal exception.
- Since:
- 0.3
Defined in the sis-utility
module
-
Method Summary
Modifier and TypeMethodDescriptionstatic Logger
getLogger
(Class<?> source) Returns a logger for the package of the specified class.static Logger
getLogger
(String name) Deprecated.static LoggerFactory<?>
Returns the factory used for obtainingLogger
instances, ornull
if none.static boolean
ignorableException
(Logger logger, Class<?> classe, String method, Throwable error) Invoked when an ignorable error occurred.static void
log
(Class<?> classe, String method, LogRecord record) Logs the given record to the logger associated to the given class.static boolean
recoverableException
(Logger logger, Class<?> classe, String method, Throwable error) Invoked when a recoverable error occurred.static void
setLoggerFactory
(LoggerFactory<?> factory) Sets a new factory to use for obtainingLogger
instances.static boolean
severeException
(Logger logger, Class<?> classe, String method, Throwable error) Invoked when a severe error occurred.static boolean
unexpectedException
(Logger logger, Class<?> classe, String method, Throwable error) Invoked when an unexpected error occurred.
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Method Details
-
setLoggerFactory
Sets a new factory to use for obtainingLogger
instances. If the givenfactory
argument isnull
(the default), then the standard Logging framework will be used.Limitation
SIS classes typically declare a logger constant like below:
Factory changes will take effect only if this method is invoked before the initialization of such classes.public static final Logger LOGGER = Logging.getLogger("the.logger.name");
- Parameters:
factory
- the new logger factory, ornull
if none.
-
getLoggerFactory
Returns the factory used for obtainingLogger
instances, ornull
if none.- Returns:
- the current logger factory, or
null
if none.
-
getLogger
Deprecated.Use the standardLogger.getLogger(String)
method instead. See SIS-531.Returns a logger for the specified name. If a logger factory has been set, then this method first asks to the factory. This rule gives SIS a chance to redirect logging events to commons-logging or some equivalent framework. Only if no factory was found or if the factory choose to not redirect the loggings, then this method delegate toLogger.getLogger(name)
.- Parameters:
name
- the logger name.- Returns:
- a logger for the specified name.
-
getLogger
Returns a logger for the package of the specified class. This convenience method invokesgetLogger(String)
with the package name of the given class taken as the logger name.- Parameters:
source
- the class which will emit a logging message.- Returns:
- a logger for the specified class.
- Since:
- 1.0
-
log
Logs the given record to the logger associated to the given class. This convenience method performs the following steps:- Unconditionally set the source class name to the canonical name of the given class;
- Unconditionally set the source method name to the given value;
- Get the logger for the logger name if specified,
or for the
classe
package name otherwise; - Set the logger name of the given record, if not already set;
- Log the modified record.
- Parameters:
classe
- the class to report as the source of the logging message.method
- the method to report as the source of the logging message.record
- the record to log.
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unexpectedException
public static boolean unexpectedException(Logger logger, Class<?> classe, String method, Throwable error) Invoked when an unexpected error occurred. This method logs a message atLevel.WARNING
to the specified logger. The originating class name and method name can optionally be specified. If any of them isnull
, then it will be inferred from the error stack trace as described below.Recommended usage: explicit value for class and method names are preferred to automatic inference for the following reasons:If the- Automatic inference is not 100% reliable, since the Java Virtual Machine is free to omit stack frame in optimized code.
- When an exception occurred in a private method used internally by a public method, we sometime want to log the warning for the public method instead, since the user is not expected to know anything about the existence of the private method. If a developer really want to know about the private method, the stack trace is still available anyway.
classe
ormethod
arguments are null, then the originating class name and method name are inferred from the givenerror
using the first stack trace element for which the class name is inside a package or sub-package of the same name than the logger name.Example: if the logger name is"org.apache.sis.image"
, then this method will uses the first stack trace element where the fully qualified class name starts with"org.apache.sis.image"
or"org.apache.sis.image.io"
, but not"org.apache.sis.imageio"
.- Parameters:
logger
- where to log the error, ornull
for inferring a default value from other arguments.classe
- the class where the error occurred, ornull
for inferring a default value from other arguments.method
- the method where the error occurred, ornull
for inferring a default value from other arguments.error
- the error, ornull
if none.- Returns:
true
if the error has been logged, orfalse
if the givenerror
was null or if the logger does not log anything atLevel.WARNING
.- See Also:
-
recoverableException
public static boolean recoverableException(Logger logger, Class<?> classe, String method, Throwable error) Invoked when a recoverable error occurred. This method is similar tounexpectedException(…)
except that it does not log the stack trace and uses a lower logging level.- Parameters:
logger
- where to log the error, ornull
for inferring a default value from other arguments.classe
- the class where the error occurred, ornull
for inferring a default value from other arguments.method
- the method name where the error occurred, ornull
for inferring a default value from other arguments.error
- the error, ornull
if none.- Returns:
true
if the error has been logged, orfalse
if the givenerror
was null or if the logger does not log anything atLevel.FINE
.- See Also:
-
ignorableException
public static boolean ignorableException(Logger logger, Class<?> classe, String method, Throwable error) Invoked when an ignorable error occurred. This method is similar tounexpectedException(…)
except that it uses a lower logging level.- Parameters:
logger
- where to log the error, ornull
for inferring a default value from other arguments.classe
- the class where the error occurred, ornull
for inferring a default value from other arguments.method
- the method name where the error occurred, ornull
for inferring a default value from other arguments.error
- the error, ornull
if none.- Returns:
true
if the error has been logged, orfalse
if the givenerror
was null or if the logger does not log anything atLevel.FINER
.- Since:
- 1.0
-
severeException
public static boolean severeException(Logger logger, Class<?> classe, String method, Throwable error) Invoked when a severe error occurred. This method is similar tounexpectedException
except that it logs the message at theSEVERE
level.- Parameters:
logger
- where to log the error, ornull
for inferring a default value from other arguments.classe
- the class where the error occurred, ornull
for inferring a default value from other arguments.method
- the method name where the error occurred, ornull
for inferring a default value from other arguments.error
- the error, ornull
if none.- Returns:
true
if the error has been logged, orfalse
if the givenerror
was null or if the logger does not log anything atLevel.SEVERE
.- See Also:
-
Logger.getLogger(String)
method instead.