Logging in Marauroa

Writing to log files or a terminal window is a low technology way of working out what your code is doing; you may also write to log files on key events to give a historical record or audit trail. The log4j package provides logging capabilities for Java programs. This page gives a quick overview of log4j, and a summary of how and where it is used in Marauroa. For more details see the [log4j home site].

Summary

The simple description is that when writing code, a logger object is created in each class definition where logging is required. Each logger has several methods that relate to the importance (level) of a message to be logged. These are TRACE < DEBUG < INFO < WARN < ERROR < FATAL with TRACE being the lowest priority and FATAL the highest. A example might be:

    logger.warn("This is a warning message");

The behaviour of the logging is controlled by a configuration file. This specifies:

• The default (root) logging level and any output stream names (appenders)

For each appender:

• The type of appender, i.e. the output stream, e.g.
  • ConsoleAppender, FileAppender, RollingFileAppender (and others)
• The format of the output
  • PatternLayout, XMLLayout
• Any format specifiers, e.g. the layout of a pattern

For each class containing a logger (optional):

• The logger class and minimum level of message that will be logged, using the levels given above plus ALL and OFF. If a class is not listed it will use the root level specified above.

A sample configuration file might look like:

# Set root logger level to INFO and its only appender to A1.
log4j.rootLogger=INFO, A1

# A1 is set to be a ConsoleAppender.
log4j.appender.A1=org.apache.log4j.ConsoleAppender

# A1 uses PatternLayout.
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n

Specify Configuration at runtime

Add the following parameters to the java command line when starting your program.

-Dlog4j.configuration="file:/C:/my/folder/log4j.properties"

-Dlog4j.debug

Marauroa

Current logging in Marauroa (assorted information) is listed below. Marauroa uses a wrapper class that would allow the log4j package to be removed, meaning the wrapper package is referenced in the main code. A few exceptions are given below.

Logging in Marauroa

Used in Class filename	Modifiers	Logger Type	Logger name	Class name / parameter
AbstractDatabaseAdapter	private static	Logger	logger
AccountDAO	private static final	marauroa.common.Logger	logger
ActionHandler	private static final	marauroa.common.Logger	logger
AdapterFactory	private static	Logger	logger
Attributes	private static	Logger	logger
BanListDAO	private static	Logger	logger
CharacterDAO	private static final	marauroa.common.Logger	logger
ChooseCharacterHandler	private static final	marauroa.common.Logger	logger
ClientFramework	private static final	marauroa.common.Logger	logger
Configuration	private static final	marauroa.common.Logger	logger
ConnectionValidator	private static final	marauroa.common.Logger	logger
CreateAccountHandler	private static final	marauroa.common.Logger	logger
CreateCharacterHandler	private static final	marauroa.common.Logger	logger
DatabaseFactory	private static final	marauroa.common.Logger	logger
DBCommandQueueBackgroundThread	private static	Logger	logger
DBTransaction	private static	Logger	logger
Decoder	private static final	marauroa.common.Logger	logger
Definition	private static final	marauroa.common.Logger	logger
DelayedEventHandlerThread	private static final	marauroa.common.Logger	logger
DisconnectHandler	private static final	marauroa.common.Logger	logger
FloodCheck	private static final	marauroa.common.Logger	logger
FloodValidator	private static final	marauroa.common.Logger	logger
GameEventDAO	private static final	marauroa.common.Logger	logger
GameServerManager	private static final	marauroa.common.Logger	logger
H2DatabaseAdapter	private static	Logger	logger	MySQLDatabaseAdapter
Hash	private static	Logger	logger
JDBCSQLHelper	private static final	marauroa.common.Logger	logger
KeepAliveHandler	private static final	marauroa.common.Logger	logger
LinkedRPObjectList	private static final	Logger	logger
LoadActiveCharacterCommand	private static	Logger	logger
LoginEventDAO	private static final	marauroa.common.Logger	logger
LoginRequestKeyHandler	private static final	marauroa.common.Logger	logger
LoginSeedDAO	private static final	marauroa.common.Logger	logger
LoginSendPromiseHandler	private static final	marauroa.common.Logger	logger
LogoutHandler	private static final	marauroa.common.Logger	logger
marauroad	private static final	Logger	logger
marauroad	private final	Logger	log
MarauroaRPZone	private static final	marauroa.common.Logger	logger
MarauroaUncaughtExceptionHandler	private static	Logger	logger
MessageDispatcher	private static final	marauroa.common.Logger	logger
MessageFactory	private static final	marauroa.common.Logger	logger	Attributes
MessageHandler	private static final	marauroa.common.Logger	logger
MessageS2CCreateAccountNACK	private static	Logger	logger
MessageS2CCreateCharacterNACK	private static	Logger	logger	MessageS2CCreateAccountNACK
MySQLDatabaseAdapter	private static	Logger	logger
NetConst	private static final	marauroa.common.Logger	logger
NioServer	private static final	marauroa.common.Logger	logger
OutOfSyncHandler	private static final	marauroa.common.Logger	logger
PerceptionHandler	private static final	marauroa.common.Logger	logger
Persistence	private final static	Logger	logger
PlayerEntry	private static	Logger	logger
PlayerEntry	private static	Logger	logger	SecuredLoginInfo
PlayerEntryContainer	private static final	marauroa.common.Logger	logger
PythonRPWorld	private static final	marauroa.common.Logger	logger
RPClass	private static final	marauroa.common.Logger	logger
RPEvent	private static final	marauroa.common.Logger	logger
RPObject	private static final	marauroa.common.Logger	logger
RPObjectDAO	private static final	marauroa.common.Logger	logger
RPObjectFactory	private static final	marauroa.common.Logger	logger
RPRuleProcessorImpl	private static	Logger	logger
RPScheduler	private static final	marauroa.common.Logger	logger
RPServerManager	private static final	marauroa.common.Logger	logger
RPSlot	private static final	marauroa.common.Logger	logger	RPObject
RPWorld	private static final	marauroa.common.Logger	logger
RPZoneDAO	private static final	marauroa.common.Logger	logger
RWLock	private static final	marauroa.common.Logger	logger
SecuredLoginHandler	private static final	marauroa.common.Logger	logger
SecuredLoginHandler	private static	Logger	infoLogger	ServerInfo
SlotOwner	private static final	marauroa.common.Logger	logger
Statistics	private static final	marauroa.common.Logger	logger
StatisticsDAO	private static final	marauroa.common.Logger	logger
TransactionPool	private static	Logger	logger
TransferACKHandler	private static final	marauroa.common.Logger	logger
UnkownMessageHandler	private static final	marauroa.common.Logger	logger
UpdateScript	private static	Logger	logger
Validator	private static	Logger	logger

Level of logging

Fatal - none

Error - 153 matches in 62 files

Warn - 76 matches in 34 files

Info - 45 matches in 18 files

Debug - 126 matches in 31 files

Log - none (method defined in Logger class)

Direct reference to Log4j

"import org.apache.log4j" is referred to in 4 files

NDC - 4 matches in 1 file

MDC - 4 matches in 2 files