Package com.google.gwt.core.ext

Class TreeLogger

java.lang.Object

com.google.gwt.core.ext.TreeLogger

public abstract class TreeLogger
extends Object

An interface used to log messages in deferred binding generators.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	TreeLogger.HelpInfo	Provides extra information to the user, generally details of what caused the problem or what the user should do to fix the problem.
static enum	TreeLogger.Type	A type-safe enum of all possible logging severity types.

Field Summary

Fields

Modifier and Type	Field	Description
static final TreeLogger.Type	ALL	Logs everything -- quite a bit of stuff.
static final TreeLogger.Type	DEBUG	Logs detailed information that could be useful during debugging.
static final TreeLogger.Type	ERROR	Logs an error.
static final TreeLogger.Type	INFO	Logs information.
static final TreeLogger	NULL	A valid logger that ignores all messages.
static final TreeLogger.Type	SPAM	Logs extremely verbose and detailed information that is typically useful only to product implementors.
static final TreeLogger.Type	TRACE	Logs information related to lower-level operation.
static final TreeLogger.Type	WARN	Logs a warning.

Constructor Summary

Constructors

Constructor	Description
TreeLogger()

Method Summary

Modifier and Type	Method	Description
final TreeLogger	branch(TreeLogger.Type type, String msg)	Calls branch(com.google.gwt.core.ext.TreeLogger.Type, String, Throwable, com.google.gwt.core.ext.TreeLogger.HelpInfo) with a null caught and helpInfo.
final TreeLogger	branch(TreeLogger.Type type, String msg, Throwable caught)	Calls branch(com.google.gwt.core.ext.TreeLogger.Type, String, Throwable, com.google.gwt.core.ext.TreeLogger.HelpInfo) with a null helpInfo.
abstract TreeLogger	branch(TreeLogger.Type type, String msg, Throwable caught, TreeLogger.HelpInfo helpInfo)	Produces a branched logger, which can be used to write messages that are logically grouped together underneath the current logger.
abstract boolean	isLoggable(TreeLogger.Type type)	Determines whether or not a log entry of the specified type would actually be logged.
final void	log(TreeLogger.Type type, String msg)	Calls log(TreeLogger.Type, String, Throwable, HelpInfo) with a null caught and helpInfo.
final void	log(TreeLogger.Type type, String msg, Throwable caught)	Calls log(TreeLogger.Type, String, Throwable, HelpInfo) with a null helpInfo.
abstract void	log(TreeLogger.Type type, String msg, Throwable caught, TreeLogger.HelpInfo helpInfo)	Logs a message and/or an exception, with optional help info.

Methods inherited from class java.lang.Object

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

Field Details

ERROR

public static final TreeLogger.Type ERROR

Logs an error.

WARN

public static final TreeLogger.Type WARN

Logs a warning.

INFO

public static final TreeLogger.Type INFO

Logs information.

TRACE

public static final TreeLogger.Type TRACE

Logs information related to lower-level operation.

DEBUG

public static final TreeLogger.Type DEBUG

Logs detailed information that could be useful during debugging.

SPAM

public static final TreeLogger.Type SPAM

Logs extremely verbose and detailed information that is typically useful only to product implementors.

ALL

public static final TreeLogger.Type ALL

Logs everything -- quite a bit of stuff.

NULL

public static final TreeLogger NULL

A valid logger that ignores all messages. Occasionally useful when calling methods that require a logger parameter.

Constructor Details

TreeLogger

public TreeLogger()

Method Details

branch

public final TreeLogger branch(TreeLogger.Type type,
 String msg)

Calls branch(com.google.gwt.core.ext.TreeLogger.Type, String, Throwable, com.google.gwt.core.ext.TreeLogger.HelpInfo) with a null caught and helpInfo.

branch

public final TreeLogger branch(TreeLogger.Type type,
 String msg,
 Throwable caught)

Calls branch(com.google.gwt.core.ext.TreeLogger.Type, String, Throwable, com.google.gwt.core.ext.TreeLogger.HelpInfo) with a null helpInfo.

branch

public abstract TreeLogger branch(TreeLogger.Type type,
 String msg,
 Throwable caught,
 TreeLogger.HelpInfo helpInfo)

Produces a branched logger, which can be used to write messages that are logically grouped together underneath the current logger. The details of how/if the resulting messages are displayed is implementation-dependent.

The log message supplied when branching serves two purposes. First, the message should be considered a heading for all the child messages below it. Second, the type of the message provides a hint as to the importance of the children below it. As an optimization, an implementation could return a "no-op" logger if messages of the specified type weren't being logged, which the implication being that all nested log messages were no more important than the level of their branch parent.

As an example of how hierarchical logging can be used, a branched logger in a GUI could write log message as child items of a parent node in a tree control. If logging to streams, such as a text console, the branched logger could prefix each entry with a unique string and indent its text so that it could be sorted later to reconstruct a proper hierarchy.

Parameters:

type -

msg - an optional message to log, which can be null if only an exception is being logged

caught - an optional exception to log, which can be null if only a message is being logged

helpInfo - extra information that might be used by the logger to provide extended information to the user

Returns:

an instance of TreeLogger representing the new branch of the log; may be the same instance on which this method is called

isLoggable

public abstract boolean isLoggable(TreeLogger.Type type)

Determines whether or not a log entry of the specified type would actually be logged. Caller use this method to avoid constructing log messages that would be thrown away.

log

public final void log(TreeLogger.Type type,
 String msg)

Calls log(TreeLogger.Type, String, Throwable, HelpInfo) with a null caught and helpInfo.

log

public final void log(TreeLogger.Type type,
 String msg,
 Throwable caught)

Calls log(TreeLogger.Type, String, Throwable, HelpInfo) with a null helpInfo.

log

public abstract void log(TreeLogger.Type type,
 String msg,
 Throwable caught,
 TreeLogger.HelpInfo helpInfo)

Logs a message and/or an exception, with optional help info. It is also legal to call this method using null arguments for both msg and caught, in which case the log event can be ignored. The info can provide extra information to the logger; a logger may choose to ignore this info.

Parameters:

type -

msg - an optional message to log, which can be null if only an exception is being logged

caught - an optional exception to log, which can be null if only a message is being logged

helpInfo - extra information that might be used by the logger to provide extended information to the user