dd.util
Class Logger

java.lang.Object
  dd.util.Logger

public class Logger

extends java.lang.Object

Provides support for logging and error messages. All logging messages eventually go through this object for storage. Logging is very simple but can be customized through changes to the implementation in this class.

There are four levels of logging provided by this class, in increasing order of severity:

• debug - Debugging messages. These may be very detailed and turned off for production code
• log - Logging messages. These are moderate-priority messages that indicate normal action.
• warning - Warning messages. These are error conditions, but errors which are recoverable (such as caught exceptions).
• error - Major errors. These are unrecoverable error conditions. The program may terminate after logging these errors.

Note that you should never create an instance of the logger, since all code should share the same log (to simplify synchronization problems). Instead, you can get the current log for this application by calling the static getDefaultLog() factory method.

There are constants defined in this file that can be modified if you wish to suppress or activiate various levels of log messages.

Author:

Eric Scharff

Field Summary

static boolean	LOG_DEBUG Determines whether debug() calls should appear in the log.
static boolean	LOG_ERROR Determines whether error() calls should appear in the log.
static boolean	LOG_LOG Determines whether log() calls should appear in the log.
static boolean	LOG_WARNING Determines whether warning() calls should appear in the log.

Method Summary

void	debug(java.lang.String debugMessage) Logs a debugging message.
void	error(java.lang.String errorMessage) Logs an error message.
static Logger	getDefaultLog() Returns the current application's logger.
void	log(java.lang.String logMessage) Logs a logging message.
void	setOutput(java.io.File outFile)
void	warning(java.lang.String warningMessage) Logs a warning message.

Methods inherited from class java.lang.Object

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

Field Detail

LOG_DEBUG

public static final boolean LOG_DEBUG

Determines whether debug() calls should appear in the log.

See Also:

Constant Field Values

LOG_LOG

public static final boolean LOG_LOG

Determines whether log() calls should appear in the log.

See Also:

Constant Field Values

LOG_WARNING

public static final boolean LOG_WARNING

Determines whether warning() calls should appear in the log.

See Also:

Constant Field Values

LOG_ERROR

public static final boolean LOG_ERROR

Determines whether error() calls should appear in the log.

See Also:

Constant Field Values

Method Detail

getDefaultLog

public static Logger getDefaultLog()

Returns the current application's logger. This factory method ensures that there is only one instance of the log per application, which dramatically simplifies synchronization and locking issues.

Returns:

the log for the currently running virtual machine

setOutput

public void setOutput(java.io.File outFile)
               throws java.io.IOException

Throws:

java.io.IOException

debug

public void debug(java.lang.String debugMessage)

Logs a debugging message. This is the lowest priority logging message and is used as an aid to debugging.

Parameters:

debugMessage - descriptive text for the log

log

public void log(java.lang.String logMessage)

Logs a logging message. This is a moderate priority message that is used to log normal behavior.

Parameters:

logMessage - descriptive text for the log

warning

public void warning(java.lang.String warningMessage)

Logs a warning message. this is a high priority message that indicates that an unexpected condition (error) occurred, but that the system is attempting to recover from the error. An example would be a caught exception. The phrase WARNING and the file name and line number are included as part of the logged message.

Parameters:

warningMessage - descriptive text for the log

error

public void error(java.lang.String errorMessage)

Logs an error message. This is the highest priority message and indicates that an unrecoverable error has occurred. Execution may terminate shortly after a call to this method. The phrase ERROR and the file name and line number are included as part of the logged message.

Parameters:

errorMessage - descriptive text for the log