Class Logger
Logger objects may be obtained by calls on one of the getLogger
factory methods. These will either create a new Logger or
return a suitable existing Logger. It is important to note that
the Logger returned by one of the getLogger
factory methods
may be garbage collected at any time if a strong reference to the
Logger is not kept.
Logging messages will be forwarded to registered Handler objects, which can forward the messages to a variety of destinations, including consoles, files, OS logs, etc.
Each Logger keeps track of a "parent" Logger, which is its nearest existing ancestor in the Logger namespace.
Each Logger has a "Level" associated with it. This reflects
a minimum Level that this logger cares about. If a Logger's
level is set to null
, then its effective level is inherited
from its parent, which may in turn obtain it recursively from its
parent, and so on up the tree.
The log level can be configured based on the properties from the
logging configuration file, as described in the description
of the LogManager class. However it may also be dynamically changed
by calls on the Logger.setLevel method. If a logger's level is
changed the change may also affect child loggers, since any child
logger that has null
as its level will inherit its
effective level from its parent.
On each logging call the Logger initially performs a cheap check of the request level (e.g., SEVERE or FINE) against the effective log level of the logger. If the request level is lower than the log level, the logging call returns immediately.
After passing this initial (cheap) test, the Logger will allocate a LogRecord to describe the logging message. It will then call a Filter (if present) to do a more detailed check on whether the record should be published. If that passes it will then publish the LogRecord to its output Handlers. By default, loggers also publish to their parent's Handlers, recursively up the tree.
Each Logger may have a ResourceBundle
associated with it.
The ResourceBundle
may be specified by name, using the
getLogger(java.lang.String, java.lang.String)
factory
method, or by value - using the setResourceBundle
method.
This bundle will be used for localizing logging messages.
If a Logger does not have its own ResourceBundle
or resource bundle
name, then it will inherit the ResourceBundle
or resource bundle name
from its parent, recursively up the tree.
Most of the logger output methods take a "msg" argument. This
msg argument may be either a raw value or a localization key.
During formatting, if the logger has (or inherits) a localization
ResourceBundle
and if the ResourceBundle
has a mapping for
the msg string, then the msg string is replaced by the localized value.
Otherwise the original msg string is used. Typically, formatters use
java.text.MessageFormat style formatting to format parameters, so
for example a format string "{0} {1}" would format two parameters
as strings.
A set of methods alternatively take a "msgSupplier" instead of a "msg"
argument. These methods take a Supplier
<String>
function
which is invoked to construct the desired log message only when the message
actually is to be logged based on the effective log level thus eliminating
unnecessary message construction. For example, if the developer wants to
log system health status for diagnosis, with the String-accepting version,
the code would look like:
class DiagnosisMessages {
static String systemHealthStatus() {
// collect system health information
...
}
}
...
logger.log(Level.FINER, DiagnosisMessages.systemHealthStatus());
With the above code, the health status is collected unnecessarily even when
the log level FINER is disabled. With the Supplier-accepting version as
below, the status will only be collected when the log level FINER is
enabled.
logger.log(Level.FINER, DiagnosisMessages::systemHealthStatus);
When looking for a ResourceBundle
, the logger will first look at
whether a bundle was specified using setResourceBundle
, and then
only whether a resource bundle name was specified through the getLogger
factory method.
If no ResourceBundle
or no resource bundle name is found,
then it will use the nearest ResourceBundle
or resource bundle
name inherited from its parent tree.
When a ResourceBundle
was inherited or specified through the
setResourceBundle
method, then
that ResourceBundle
will be used. Otherwise if the logger only
has or inherited a resource bundle name, then that resource bundle name
will be mapped to a ResourceBundle
object, using the default Locale
at the time of logging.
When mapping resource bundle names to
ResourceBundle
objects, the logger will first try to use the
Thread's context class
loader to map the given resource bundle name to a ResourceBundle
.
If the thread context class loader is null
, it will try the
system class loader
instead. If the ResourceBundle
is still not found, it will use the
class loader of the first caller of the getLogger
factory method.
Formatting (including localization) is the responsibility of the output Handler, which will typically call a Formatter.
Note that formatting need not occur synchronously. It may be delayed until a LogRecord is actually written to an external sink.
The logging methods are grouped in five main categories:
There are a set of "log" methods that take a log level, a message string, and optionally some parameters to the message string.
There are a set of "logp" methods (for "log precise") that are like the "log" methods, but also take an explicit source class name and method name.
There are a set of "logrb" method (for "log with resource bundle") that are like the "logp" method, but also take an explicit resource bundle object for use in localizing the log message.
There are convenience methods for tracing method entries (the "entering" methods), method returns (the "exiting" methods) and throwing exceptions (the "throwing" methods).
Finally, there are a set of convenience methods for use in the very simplest cases, when a developer simply wants to log a simple string at a given log level. These methods are named after the standard Level names ("severe", "warning", "info", etc.) and take a single argument, a message string.
For the methods that do not take an explicit source name and method name, the Logging framework will make a "best effort" to determine which class and method called into the logging method. However, it is important to realize that this automatically inferred information may only be approximate (or may even be quite wrong!). Virtual machines are allowed to do extensive optimizations when JITing and may entirely remove stack frames, making it impossible to reliably locate the calling class and method.
All methods on Logger are multi-thread safe.
Subclassing Information: Note that a LogManager class may provide its own implementation of named Loggers for any point in the namespace. Therefore, any subclasses of Logger (unless they are implemented in conjunction with a new LogManager class) should take care to obtain a Logger instance from the LogManager class and should delegate operations such as "isLoggable" and "log(LogRecord)" to that instance. Note that in order to intercept all logging output, subclasses need only override the log(LogRecord) method. All the other logging methods are implemented as calls on this log(LogRecord) method.
- Since:
- 1.4
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Field Summary
-
Constructor Summary
-
Method Summary
Modifier and TypeMethodDescriptionvoid
addHandler
(Handler handler) Add a log Handler to receive logging messages.void
Log a CONFIG message.void
Log a CONFIG message, which is only to be constructed if the logging level is such that the message will actually be logged.void
Log a method entry.void
Log a method entry, with one parameter.void
Log a method entry, with an array of parameters.void
Log a method return.void
Log a method return, with result object.void
Log a FINE message.void
Log a FINE message, which is only to be constructed if the logging level is such that the message will actually be logged.void
Log a FINER message.void
Log a FINER message, which is only to be constructed if the logging level is such that the message will actually be logged.void
Log a FINEST message.void
Log a FINEST message, which is only to be constructed if the logging level is such that the message will actually be logged.static Logger
Create an anonymous Logger.static Logger
getAnonymousLogger
(String resourceBundleName) Create an anonymous Logger.Get the current filter for this Logger.static final Logger
Return global logger object with the name Logger.GLOBAL_LOGGER_NAME.Handler[]
Get the Handlers associated with this logger.getLevel()
Get the log Level that has been specified for this Logger.static Logger
Find or create a logger for a named subsystem.static Logger
Find or create a logger for a named subsystem.getName()
Get the name for this logger.Return the parent for this Logger.Retrieve the localization resource bundle for this logger.Retrieve the localization resource bundle name for this logger.boolean
Discover whether or not this logger is sending its output to its parent logger.void
Log an INFO message.void
Log a INFO message, which is only to be constructed if the logging level is such that the message will actually be logged.boolean
isLoggable
(Level level) Check if a message of the given level would actually be logged by this logger.void
Log a message, with no arguments.void
Log a message, with one object parameter.void
Log a message, with an array of object arguments.void
Log a message, with associated Throwable information.void
Log a lazily constructed message, with associated Throwable information.void
Log a message, which is only to be constructed if the logging level is such that the message will actually be logged.void
Log a LogRecord.void
Log a message, specifying source class and method, with no arguments.void
Log a message, specifying source class and method, with a single object parameter to the log message.void
Log a message, specifying source class and method, with an array of object arguments.void
Log a message, specifying source class and method, with associated Throwable information.void
logp
(Level level, String sourceClass, String sourceMethod, Throwable thrown, Supplier<String> msgSupplier) Log a lazily constructed message, specifying source class and method, with associated Throwable information.void
Log a lazily constructed message, specifying source class and method, with no arguments.void
void
logrb
(Level level, String sourceClass, String sourceMethod, String bundleName, String msg, Object param1) void
logrb
(Level level, String sourceClass, String sourceMethod, String bundleName, String msg, Object[] params) void
logrb
(Level level, String sourceClass, String sourceMethod, String bundleName, String msg, Throwable thrown) void
logrb
(Level level, String sourceClass, String sourceMethod, ResourceBundle bundle, String msg, Object... params) Log a message, specifying source class, method, and resource bundle, with an optional list of message parameters.void
logrb
(Level level, String sourceClass, String sourceMethod, ResourceBundle bundle, String msg, Throwable thrown) Log a message, specifying source class, method, and resource bundle, with associated Throwable information.void
logrb
(Level level, ResourceBundle bundle, String msg, Object... params) Log a message, specifying source class, method, and resource bundle, with an optional list of message parameters.void
logrb
(Level level, ResourceBundle bundle, String msg, Throwable thrown) Log a message, specifying source class, method, and resource bundle, with associated Throwable information.void
removeHandler
(Handler handler) Remove a log Handler.void
Set a filter to control output on this Logger.void
Set the log level specifying which message levels will be logged by this logger.void
Set the parent for this Logger.void
setResourceBundle
(ResourceBundle bundle) Sets a resource bundle on this logger.void
setUseParentHandlers
(boolean useParentHandlers) Specify whether or not this logger should send its output to its parent Logger.void
Log a SEVERE message.void
Log a SEVERE message, which is only to be constructed if the logging level is such that the message will actually be logged.void
Log throwing an exception.void
Log a WARNING message.void
Log a WARNING message, which is only to be constructed if the logging level is such that the message will actually be logged.
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Field Details
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GLOBAL_LOGGER_NAME
GLOBAL_LOGGER_NAME is a name for the global logger.- Since:
- 1.6
- See Also:
-
global
Deprecated.Initialization of this field is prone to deadlocks. The field must be initialized by the Logger class initialization which may cause deadlocks with the LogManager class initialization. In such cases two class initialization wait for each other to complete. The preferred way to get the global logger object is via the callLogger.getGlobal()
. For compatibility with old JDK versions where theLogger.getGlobal()
is not available use the callLogger.getLogger(Logger.GLOBAL_LOGGER_NAME)
orLogger.getLogger("global")
.The "global" Logger object is provided as a convenience to developers who are making casual use of the Logging package. Developers who are making serious use of the logging package (for example in products) should create and use their own Logger objects, with appropriate names, so that logging can be controlled on a suitable per-Logger granularity. Developers also need to keep a strong reference to their Logger objects to prevent them from being garbage collected.
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-
Constructor Details
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Logger
Protected method to construct a logger for a named subsystem.The logger will be initially configured with a null Level and with useParentHandlers set to true.
- Parameters:
name
- A name for the logger. This should be a dot-separated name and should normally be based on the package name or class name of the subsystem, such as java.net or javax.swing. It may be null for anonymous Loggers.resourceBundleName
- name of ResourceBundle to be used for localizing messages for this logger. May be null if none of the messages require localization.- Throws:
MissingResourceException
- if the resourceBundleName is non-null and no corresponding resource can be found.
-
-
Method Details
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getGlobal
Return global logger object with the name Logger.GLOBAL_LOGGER_NAME.- Returns:
- global logger object
- Since:
- 1.7
-
getLogger
Find or create a logger for a named subsystem. If a logger has already been created with the given name it is returned. Otherwise a new logger is created.If a new logger is created its log level will be configured based on the LogManager configuration and it will be configured to also send logging output to its parent's Handlers. It will be registered in the LogManager global namespace.
Note: The LogManager may only retain a weak reference to the newly created Logger. It is important to understand that a previously created Logger with the given name may be garbage collected at any time if there is no strong reference to the Logger. In particular, this means that two back-to-back calls like
getLogger("MyLogger").log(...)
may use different Logger objects named "MyLogger" if there is no strong reference to the Logger named "MyLogger" elsewhere in the program.- Parameters:
name
- A name for the logger. This should be a dot-separated name and should normally be based on the package name or class name of the subsystem, such as java.net or javax.swing- Returns:
- a suitable Logger
- Throws:
NullPointerException
- if the name is null.
-
getLogger
Find or create a logger for a named subsystem. If a logger has already been created with the given name it is returned. Otherwise a new logger is created.If a new logger is created its log level will be configured based on the LogManager and it will be configured to also send logging output to its parent's Handlers. It will be registered in the LogManager global namespace.
Note: The LogManager may only retain a weak reference to the newly created Logger. It is important to understand that a previously created Logger with the given name may be garbage collected at any time if there is no strong reference to the Logger. In particular, this means that two back-to-back calls like
getLogger("MyLogger", ...).log(...)
may use different Logger objects named "MyLogger" if there is no strong reference to the Logger named "MyLogger" elsewhere in the program.If the named Logger already exists and does not yet have a localization resource bundle then the given resource bundle name is used. If the named Logger already exists and has a different resource bundle name then an IllegalArgumentException is thrown.
- Parameters:
name
- A name for the logger. This should be a dot-separated name and should normally be based on the package name or class name of the subsystem, such as java.net or javax.swingresourceBundleName
- name of ResourceBundle to be used for localizing messages for this logger. May benull
if none of the messages require localization.- Returns:
- a suitable Logger
- Throws:
MissingResourceException
- if the resourceBundleName is non-null and no corresponding resource can be found.IllegalArgumentException
- if the Logger already exists and uses a different resource bundle name; or ifresourceBundleName
isnull
but the named logger has a resource bundle set.NullPointerException
- if the name is null.
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getAnonymousLogger
Create an anonymous Logger. The newly created Logger is not registered in the LogManager namespace.This factory method was primarily intended for use from applets. Because the resulting Logger is anonymous it can be kept private by the creating class. This removed the need for normal security checks, which in turn allowed untrusted applet code to update the control state of the Logger. For example an applet could do a setLevel or an addHandler on an anonymous Logger.
Even although the new logger is anonymous, it is configured to have the root logger ("") as its parent. This means that by default it inherits its effective level and handlers from the root logger.
- Returns:
- a newly created private Logger
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getAnonymousLogger
Create an anonymous Logger. The newly created Logger is not registered in the LogManager namespace.This factory method was primarily intended for use from applets. Because the resulting Logger is anonymous it can be kept private by the creating class. This removed the need for normal security checks, which in turn allowed untrusted applet code to update the control state of the Logger. For example an applet could do a setLevel or an addHandler on an anonymous Logger.
Even although the new logger is anonymous, it is configured to have the root logger ("") as its parent. This means that by default it inherits its effective level and handlers from the root logger.
- Parameters:
resourceBundleName
- name of ResourceBundle to be used for localizing messages for this logger. May be null if none of the messages require localization.- Returns:
- a newly created private Logger
- Throws:
MissingResourceException
- if the resourceBundleName is non-null and no corresponding resource can be found.
-
getResourceBundle
Retrieve the localization resource bundle for this logger. This method will return aResourceBundle
that was either set by thesetResourceBundle
method or mapped from the the resource bundle name set via thegetLogger
factory method for the current default locale.
Note that if the result isnull
, then the Logger will use a resource bundle or resource bundle name inherited from its parent.- Returns:
- localization bundle (may be
null
)
-
getResourceBundleName
Retrieve the localization resource bundle name for this logger. This is either the name specified through thegetLogger
factory method, or the base name of the ResourceBundle set throughsetResourceBundle
method.
Note that if the result isnull
, then the Logger will use a resource bundle or resource bundle name inherited from its parent.- Returns:
- localization bundle name (may be
null
)
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setFilter
Set a filter to control output on this Logger.After passing the initial "level" check, the Logger will call this Filter to check if a log record should really be published.
- Parameters:
newFilter
- a filter object (may be null)
-
getFilter
Get the current filter for this Logger.- Returns:
- a filter object (may be null)
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log
Log a LogRecord.All the other logging methods in this class call through this method to actually perform any logging. Subclasses can override this single method to capture all log activity.
- Parameters:
record
- the LogRecord to be published
-
log
Log a message, with no arguments.If the logger is currently enabled for the given message level then the given message is forwarded to all the registered output Handler objects.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREmsg
- The string message (or a key in the message catalog)
-
log
Log a message, which is only to be constructed if the logging level is such that the message will actually be logged.If the logger is currently enabled for the given message level then the message is constructed by invoking the provided supplier function and forwarded to all the registered output Handler objects.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREmsgSupplier
- A function, which when called, produces the desired log message- Since:
- 1.8
-
log
Log a message, with one object parameter.If the logger is currently enabled for the given message level then a corresponding LogRecord is created and forwarded to all the registered output Handler objects.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREmsg
- The string message (or a key in the message catalog)param1
- parameter to the message
-
log
Log a message, with an array of object arguments.If the logger is currently enabled for the given message level then a corresponding LogRecord is created and forwarded to all the registered output Handler objects.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREmsg
- The string message (or a key in the message catalog)params
- array of parameters to the message
-
log
Log a message, with associated Throwable information.If the logger is currently enabled for the given message level then the given arguments are stored in a LogRecord which is forwarded to all registered output handlers.
Note that the thrown argument is stored in the LogRecord thrown property, rather than the LogRecord parameters property. Thus it is processed specially by output Formatters and is not treated as a formatting parameter to the LogRecord message property.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREmsg
- The string message (or a key in the message catalog)thrown
- Throwable associated with log message.
-
log
Log a lazily constructed message, with associated Throwable information.If the logger is currently enabled for the given message level then the message is constructed by invoking the provided supplier function. The message and the given
Throwable
are then stored in aLogRecord
which is forwarded to all registered output handlers.Note that the thrown argument is stored in the LogRecord thrown property, rather than the LogRecord parameters property. Thus it is processed specially by output Formatters and is not treated as a formatting parameter to the LogRecord message property.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREthrown
- Throwable associated with log message.msgSupplier
- A function, which when called, produces the desired log message- Since:
- 1.8
-
logp
Log a message, specifying source class and method, with no arguments.If the logger is currently enabled for the given message level then the given message is forwarded to all the registered output Handler objects.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREsourceClass
- name of class that issued the logging requestsourceMethod
- name of method that issued the logging requestmsg
- The string message (or a key in the message catalog)
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logp
public void logp(Level level, String sourceClass, String sourceMethod, Supplier<String> msgSupplier) Log a lazily constructed message, specifying source class and method, with no arguments.If the logger is currently enabled for the given message level then the message is constructed by invoking the provided supplier function and forwarded to all the registered output Handler objects.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREsourceClass
- name of class that issued the logging requestsourceMethod
- name of method that issued the logging requestmsgSupplier
- A function, which when called, produces the desired log message- Since:
- 1.8
-
logp
Log a message, specifying source class and method, with a single object parameter to the log message.If the logger is currently enabled for the given message level then a corresponding LogRecord is created and forwarded to all the registered output Handler objects.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREsourceClass
- name of class that issued the logging requestsourceMethod
- name of method that issued the logging requestmsg
- The string message (or a key in the message catalog)param1
- Parameter to the log message.
-
logp
Log a message, specifying source class and method, with an array of object arguments.If the logger is currently enabled for the given message level then a corresponding LogRecord is created and forwarded to all the registered output Handler objects.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREsourceClass
- name of class that issued the logging requestsourceMethod
- name of method that issued the logging requestmsg
- The string message (or a key in the message catalog)params
- Array of parameters to the message
-
logp
public void logp(Level level, String sourceClass, String sourceMethod, String msg, Throwable thrown) Log a message, specifying source class and method, with associated Throwable information.If the logger is currently enabled for the given message level then the given arguments are stored in a LogRecord which is forwarded to all registered output handlers.
Note that the thrown argument is stored in the LogRecord thrown property, rather than the LogRecord parameters property. Thus it is processed specially by output Formatters and is not treated as a formatting parameter to the LogRecord message property.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREsourceClass
- name of class that issued the logging requestsourceMethod
- name of method that issued the logging requestmsg
- The string message (or a key in the message catalog)thrown
- Throwable associated with log message.
-
logp
public void logp(Level level, String sourceClass, String sourceMethod, Throwable thrown, Supplier<String> msgSupplier) Log a lazily constructed message, specifying source class and method, with associated Throwable information.If the logger is currently enabled for the given message level then the message is constructed by invoking the provided supplier function. The message and the given
Throwable
are then stored in aLogRecord
which is forwarded to all registered output handlers.Note that the thrown argument is stored in the LogRecord thrown property, rather than the LogRecord parameters property. Thus it is processed specially by output Formatters and is not treated as a formatting parameter to the LogRecord message property.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREsourceClass
- name of class that issued the logging requestsourceMethod
- name of method that issued the logging requestthrown
- Throwable associated with log message.msgSupplier
- A function, which when called, produces the desired log message- Since:
- 1.8
-
logrb
@Deprecated public void logrb(Level level, String sourceClass, String sourceMethod, String bundleName, String msg) Deprecated.Log a message, specifying source class, method, and resource bundle name with no arguments.If the logger is currently enabled for the given message level then the given message is forwarded to all the registered output Handler objects.
The msg string is localized using the named resource bundle. If the resource bundle name is null, or an empty String or invalid then the msg string is not localized.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREsourceClass
- name of class that issued the logging requestsourceMethod
- name of method that issued the logging requestbundleName
- name of resource bundle to localize msg, can be nullmsg
- The string message (or a key in the message catalog)
-
logrb
@Deprecated public void logrb(Level level, String sourceClass, String sourceMethod, String bundleName, String msg, Object param1) Deprecated.Log a message, specifying source class, method, and resource bundle name, with a single object parameter to the log message.If the logger is currently enabled for the given message level then a corresponding LogRecord is created and forwarded to all the registered output Handler objects.
The msg string is localized using the named resource bundle. If the resource bundle name is null, or an empty String or invalid then the msg string is not localized.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREsourceClass
- name of class that issued the logging requestsourceMethod
- name of method that issued the logging requestbundleName
- name of resource bundle to localize msg, can be nullmsg
- The string message (or a key in the message catalog)param1
- Parameter to the log message.
-
logrb
@Deprecated public void logrb(Level level, String sourceClass, String sourceMethod, String bundleName, String msg, Object[] params) Deprecated.Log a message, specifying source class, method, and resource bundle name, with an array of object arguments.If the logger is currently enabled for the given message level then a corresponding LogRecord is created and forwarded to all the registered output Handler objects.
The msg string is localized using the named resource bundle. If the resource bundle name is null, or an empty String or invalid then the msg string is not localized.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREsourceClass
- name of class that issued the logging requestsourceMethod
- name of method that issued the logging requestbundleName
- name of resource bundle to localize msg, can be null.msg
- The string message (or a key in the message catalog)params
- Array of parameters to the message
-
logrb
public void logrb(Level level, String sourceClass, String sourceMethod, ResourceBundle bundle, String msg, Object... params) Log a message, specifying source class, method, and resource bundle, with an optional list of message parameters.If the logger is currently enabled for the given message
level
then a correspondingLogRecord
is created and forwarded to all the registered outputHandler
objects.The
msg
string is localized using the given resource bundle. If the resource bundle isnull
, then themsg
string is not localized.- Parameters:
level
- One of the message level identifiers, e.g.,SEVERE
sourceClass
- Name of the class that issued the logging requestsourceMethod
- Name of the method that issued the logging requestbundle
- Resource bundle to localizemsg
, can benull
.msg
- The string message (or a key in the message catalog)params
- Parameters to the message (optional, may be none).- Since:
- 1.8
-
logrb
Log a message, specifying source class, method, and resource bundle, with an optional list of message parameters.If the logger is currently enabled for the given message
level
then a correspondingLogRecord
is created and forwarded to all the registered outputHandler
objects.The
msg
string is localized using the given resource bundle. If the resource bundle isnull
, then themsg
string is not localized.- Parameters:
level
- One of the message level identifiers, e.g.,SEVERE
bundle
- Resource bundle to localizemsg
; can benull
.msg
- The string message (or a key in the message catalog)params
- Parameters to the message (optional, may be none).- Since:
- 9
-
logrb
@Deprecated public void logrb(Level level, String sourceClass, String sourceMethod, String bundleName, String msg, Throwable thrown) Deprecated.Log a message, specifying source class, method, and resource bundle name, with associated Throwable information.If the logger is currently enabled for the given message level then the given arguments are stored in a LogRecord which is forwarded to all registered output handlers.
The msg string is localized using the named resource bundle. If the resource bundle name is null, or an empty String or invalid then the msg string is not localized.
Note that the thrown argument is stored in the LogRecord thrown property, rather than the LogRecord parameters property. Thus it is processed specially by output Formatters and is not treated as a formatting parameter to the LogRecord message property.
- Parameters:
level
- One of the message level identifiers, e.g., SEVEREsourceClass
- name of class that issued the logging requestsourceMethod
- name of method that issued the logging requestbundleName
- name of resource bundle to localize msg, can be nullmsg
- The string message (or a key in the message catalog)thrown
- Throwable associated with log message.
-
logrb
public void logrb(Level level, String sourceClass, String sourceMethod, ResourceBundle bundle, String msg, Throwable thrown) Log a message, specifying source class, method, and resource bundle, with associated Throwable information.If the logger is currently enabled for the given message
level
then the given arguments are stored in aLogRecord
which is forwarded to all registered output handlers.The
msg
string is localized using the given resource bundle. If the resource bundle isnull
, then themsg
string is not localized.Note that the
thrown
argument is stored in theLogRecord
thrown
property, rather than theLogRecord
parameters
property. Thus it is processed specially by outputFormatter
objects and is not treated as a formatting parameter to theLogRecord
message
property.- Parameters:
level
- One of the message level identifiers, e.g.,SEVERE
sourceClass
- Name of the class that issued the logging requestsourceMethod
- Name of the method that issued the logging requestbundle
- Resource bundle to localizemsg
, can benull
msg
- The string message (or a key in the message catalog)thrown
- Throwable associated with the log message.- Since:
- 1.8
-
logrb
Log a message, specifying source class, method, and resource bundle, with associated Throwable information.If the logger is currently enabled for the given message
level
then the given arguments are stored in aLogRecord
which is forwarded to all registered output handlers.The
msg
string is localized using the given resource bundle. If the resource bundle isnull
, then themsg
string is not localized.Note that the
thrown
argument is stored in theLogRecord
thrown
property, rather than theLogRecord
parameters
property. Thus it is processed specially by outputFormatter
objects and is not treated as a formatting parameter to theLogRecord
message
property.- Parameters:
level
- One of the message level identifiers, e.g.,SEVERE
bundle
- Resource bundle to localizemsg
; can benull
.msg
- The string message (or a key in the message catalog)thrown
- Throwable associated with the log message.- Since:
- 9
-
entering
Log a method entry.This is a convenience method that can be used to log entry to a method. A LogRecord with message "ENTRY", log level FINER, and the given sourceMethod and sourceClass is logged.
- Parameters:
sourceClass
- name of class that issued the logging requestsourceMethod
- name of method that is being entered
-
entering
Log a method entry, with one parameter.This is a convenience method that can be used to log entry to a method. A LogRecord with message "ENTRY {0}", log level FINER, and the given sourceMethod, sourceClass, and parameter is logged.
- Parameters:
sourceClass
- name of class that issued the logging requestsourceMethod
- name of method that is being enteredparam1
- parameter to the method being entered
-
entering
Log a method entry, with an array of parameters.This is a convenience method that can be used to log entry to a method. A LogRecord with message "ENTRY" (followed by a format {N} indicator for each entry in the parameter array), log level FINER, and the given sourceMethod, sourceClass, and parameters is logged.
- Parameters:
sourceClass
- name of class that issued the logging requestsourceMethod
- name of method that is being enteredparams
- array of parameters to the method being entered
-
exiting
Log a method return.This is a convenience method that can be used to log returning from a method. A LogRecord with message "RETURN", log level FINER, and the given sourceMethod and sourceClass is logged.
- Parameters:
sourceClass
- name of class that issued the logging requestsourceMethod
- name of the method
-
exiting
Log a method return, with result object.This is a convenience method that can be used to log returning from a method. A LogRecord with message "RETURN {0}", log level FINER, and the gives sourceMethod, sourceClass, and result object is logged.
- Parameters:
sourceClass
- name of class that issued the logging requestsourceMethod
- name of the methodresult
- Object that is being returned
-
throwing
Log throwing an exception.This is a convenience method to log that a method is terminating by throwing an exception. The logging is done using the FINER level.
If the logger is currently enabled for the given message level then the given arguments are stored in a LogRecord which is forwarded to all registered output handlers. The LogRecord's message is set to "THROW".
Note that the thrown argument is stored in the LogRecord thrown property, rather than the LogRecord parameters property. Thus it is processed specially by output Formatters and is not treated as a formatting parameter to the LogRecord message property.
- Parameters:
sourceClass
- name of class that issued the logging requestsourceMethod
- name of the method.thrown
- The Throwable that is being thrown.
-
severe
Log a SEVERE message.If the logger is currently enabled for the SEVERE message level then the given message is forwarded to all the registered output Handler objects.
- Parameters:
msg
- The string message (or a key in the message catalog)
-
warning
Log a WARNING message.If the logger is currently enabled for the WARNING message level then the given message is forwarded to all the registered output Handler objects.
- Parameters:
msg
- The string message (or a key in the message catalog)
-
info
Log an INFO message.If the logger is currently enabled for the INFO message level then the given message is forwarded to all the registered output Handler objects.
- Parameters:
msg
- The string message (or a key in the message catalog)
-
config
Log a CONFIG message.If the logger is currently enabled for the CONFIG message level then the given message is forwarded to all the registered output Handler objects.
- Parameters:
msg
- The string message (or a key in the message catalog)
-
fine
Log a FINE message.If the logger is currently enabled for the FINE message level then the given message is forwarded to all the registered output Handler objects.
- Parameters:
msg
- The string message (or a key in the message catalog)
-
finer
Log a FINER message.If the logger is currently enabled for the FINER message level then the given message is forwarded to all the registered output Handler objects.
- Parameters:
msg
- The string message (or a key in the message catalog)
-
finest
Log a FINEST message.If the logger is currently enabled for the FINEST message level then the given message is forwarded to all the registered output Handler objects.
- Parameters:
msg
- The string message (or a key in the message catalog)
-
severe
Log a SEVERE message, which is only to be constructed if the logging level is such that the message will actually be logged.If the logger is currently enabled for the SEVERE message level then the message is constructed by invoking the provided supplier function and forwarded to all the registered output Handler objects.
- Parameters:
msgSupplier
- A function, which when called, produces the desired log message- Since:
- 1.8
-
warning
Log a WARNING message, which is only to be constructed if the logging level is such that the message will actually be logged.If the logger is currently enabled for the WARNING message level then the message is constructed by invoking the provided supplier function and forwarded to all the registered output Handler objects.
- Parameters:
msgSupplier
- A function, which when called, produces the desired log message- Since:
- 1.8
-
info
Log a INFO message, which is only to be constructed if the logging level is such that the message will actually be logged.If the logger is currently enabled for the INFO message level then the message is constructed by invoking the provided supplier function and forwarded to all the registered output Handler objects.
- Parameters:
msgSupplier
- A function, which when called, produces the desired log message- Since:
- 1.8
-
config
Log a CONFIG message, which is only to be constructed if the logging level is such that the message will actually be logged.If the logger is currently enabled for the CONFIG message level then the message is constructed by invoking the provided supplier function and forwarded to all the registered output Handler objects.
- Parameters:
msgSupplier
- A function, which when called, produces the desired log message- Since:
- 1.8
-
fine
Log a FINE message, which is only to be constructed if the logging level is such that the message will actually be logged.If the logger is currently enabled for the FINE message level then the message is constructed by invoking the provided supplier function and forwarded to all the registered output Handler objects.
- Parameters:
msgSupplier
- A function, which when called, produces the desired log message- Since:
- 1.8
-
finer
Log a FINER message, which is only to be constructed if the logging level is such that the message will actually be logged.If the logger is currently enabled for the FINER message level then the message is constructed by invoking the provided supplier function and forwarded to all the registered output Handler objects.
- Parameters:
msgSupplier
- A function, which when called, produces the desired log message- Since:
- 1.8
-
finest
Log a FINEST message, which is only to be constructed if the logging level is such that the message will actually be logged.If the logger is currently enabled for the FINEST message level then the message is constructed by invoking the provided supplier function and forwarded to all the registered output Handler objects.
- Parameters:
msgSupplier
- A function, which when called, produces the desired log message- Since:
- 1.8
-
setLevel
Set the log level specifying which message levels will be logged by this logger. Message levels lower than this value will be discarded. The level value Level.OFF can be used to turn off logging.If the new level is null, it means that this node should inherit its level from its nearest ancestor with a specific (non-null) level value.
- Parameters:
newLevel
- the new value for the log level (may be null)
-
getLevel
Get the log Level that has been specified for this Logger. The result may be null, which means that this logger's effective level will be inherited from its parent.- Returns:
- this Logger's level
-
isLoggable
Check if a message of the given level would actually be logged by this logger. This check is based on the Loggers effective level, which may be inherited from its parent.- Parameters:
level
- a message logging level- Returns:
- true if the given message level is currently being logged.
-
getName
Get the name for this logger.- Returns:
- logger name. Will be null for anonymous Loggers.
-
addHandler
Add a log Handler to receive logging messages.By default, Loggers also send their output to their parent logger. Typically the root Logger is configured with a set of Handlers that essentially act as default handlers for all loggers.
- Parameters:
handler
- a logging Handler
-
removeHandler
Remove a log Handler.Returns silently if the given Handler is not found or is null
- Parameters:
handler
- a logging Handler
-
getHandlers
Get the Handlers associated with this logger.- Returns:
- an array of all registered Handlers
-
setUseParentHandlers
public void setUseParentHandlers(boolean useParentHandlers) Specify whether or not this logger should send its output to its parent Logger. This means that any LogRecords will also be written to the parent's Handlers, and potentially to its parent, recursively up the namespace.- Parameters:
useParentHandlers
- true if output is to be sent to the logger's parent.
-
getUseParentHandlers
public boolean getUseParentHandlers()Discover whether or not this logger is sending its output to its parent logger.- Returns:
- true if output is to be sent to the logger's parent
-
setResourceBundle
Sets a resource bundle on this logger. All messages will be logged using the given resource bundle for its specific locale.- Parameters:
bundle
- The resource bundle that this logger shall use.- Throws:
NullPointerException
- if the given bundle isnull
.IllegalArgumentException
- if the given bundle doesn't have a base name, or if this logger already has a resource bundle set but the given bundle has a different base name.- Since:
- 1.8
-
getParent
Return the parent for this Logger.This method returns the nearest extant parent in the namespace. Thus if a Logger is called "a.b.c.d", and a Logger called "a.b" has been created but no logger "a.b.c" exists, then a call of getParent on the Logger "a.b.c.d" will return the Logger "a.b".
The result will be null if it is called on the root Logger in the namespace.
- Returns:
- nearest existing parent Logger
-
setParent
Set the parent for this Logger. This method is used by the LogManager to update a Logger when the namespace changes.It should not be called from application code.
- Parameters:
parent
- the new parent logger
-