ConsoleHandler

AI-generated Key Takeaways

• ConsoleHandler publishes log records to System.err, using SimpleFormatter for brief summaries by default.

• It can be configured via LogManager properties to define the logging level, filter, formatter, and character encoding.

• ConsoleHandler inherits methods for managing the output stream, including publish, close, and flush, from StreamHandler.

• The constructor ConsoleHandler() initializes a new handler for System.err based on LogManager properties or defaults.

• The publish method writes a LogRecord to the console, while close performs a flush without closing System.err.

public class ConsoleHandler extends StreamHandler

This Handler publishes log records to System.err. By default the SimpleFormatter is used to generate brief summaries.

Configuration: By default each ConsoleHandler is initialized using the following LogManager configuration properties where <handler-name> refers to the fully-qualified class name of the handler. If properties are not defined (or have invalid values) then the specified default values are used.

• <handler-name>.level specifies the default level for the Handler (defaults to Level.INFO).
• <handler-name>.filter specifies the name of a Filter class to use (defaults to no Filter).
• <handler-name>.formatter specifies the name of a Formatter class to use (defaults to java.util.logging.SimpleFormatter).
• <handler-name>.encoding the name of the character set encoding to use (defaults to the default platform encoding).

For example, the properties for ConsoleHandler would be:

• java.util.logging.ConsoleHandler.level=INFO
• java.util.logging.ConsoleHandler.formatter=java.util.logging.SimpleFormatter

For a custom handler, e.g. com.foo.MyHandler, the properties would be:

• com.foo.MyHandler.level=INFO
• com.foo.MyHandler.formatter=java.util.logging.SimpleFormatter

Public Constructor Summary

ConsoleHandler() Create a ConsoleHandler for System.err.

Public Method Summary

void	close() Override StreamHandler.close to do a flush but not to close the output stream.
void	publish(LogRecord record) Publish a LogRecord.

Inherited Method Summary

From class java.util.logging.StreamHandler

synchronized void	close() Close the current output stream.
synchronized void	flush() Flush any buffered messages.
boolean	isLoggable(LogRecord record) Check if this Handler would actually log a given LogRecord.
synchronized void	publish(LogRecord record) Format and publish a LogRecord.
synchronized void	setEncoding(String encoding) Set (or change) the character encoding used by this Handler.
synchronized void	setOutputStream(OutputStream out) Change the output stream.

From class java.util.logging.Handler

abstract void	close() Close the Handler and free all associated resources.
abstract void	flush() Flush any buffered output.
String	getEncoding() Return the character encoding for this Handler.
ErrorManager	getErrorManager() Retrieves the ErrorManager for this Handler.
Filter	getFilter() Get the current Filter for this Handler.
Formatter	getFormatter() Return the Formatter for this Handler.
Level	getLevel() Get the log level specifying which messages will be logged by this Handler.
boolean	isLoggable(LogRecord record) Check if this Handler would actually log a given LogRecord.
abstract void	publish(LogRecord record) Publish a LogRecord.
void	reportError(String msg, Exception ex, int code) Protected convenience method to report an error to this Handler's ErrorManager.
synchronized void	setEncoding(String encoding) Set the character encoding used by this Handler.
synchronized void	setErrorManager(ErrorManager em) Define an ErrorManager for this Handler.
synchronized void	setFilter(Filter newFilter) Set a Filter to control output on this Handler.
synchronized void	setFormatter(Formatter newFormatter) Set a Formatter.
synchronized void	setLevel(Level newLevel) Set the log level specifying which message levels will be logged by this Handler.

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Public Constructors

public ConsoleHandler ()

Create a ConsoleHandler for System.err.

The ConsoleHandler is configured based on LogManager properties (or their default values).

Public Methods

public void close ()

Override StreamHandler.close to do a flush but not to close the output stream. That is, we do not close System.err.

public void publish (LogRecord record)

Publish a LogRecord.

The logging request was made initially to a Logger object, which initialized the LogRecord and forwarded it here.

Parameters

record	description of the log event. A null record is silently ignored and is not published