hydra

Class Log

java.lang.Object

hydra.Log

public class Log
extends Object

Manages a singleton instance of LogWriter to do all the logging for a VM. The instance is created using createLogWriter and accessed using getLogWriter.

Constructor Summary

Constructors

Constructor and Description
Log()

Method Summary

Modifier and Type	Method and Description
static void	cacheLogWriter() Caches the singleton log writer so another log writer can be created.
static void	closeLogWriter() Closes the singleton log writer.
static com.gemstone.gemfire.LogWriter	createLogWriter(String name, String levelName) Creates a singleton log writer that logs to stdout.
static com.gemstone.gemfire.LogWriter	createLogWriter(String name, String filePrefix, boolean fileLogging, String fileLogLevelName, int fileMaxKBPerVM) Creates a singleton log writer that logs to a file.
static com.gemstone.gemfire.LogWriter	createLogWriter(String name, String filePrefix, String levelName, boolean append) Creates a singleton log writer that logs to a file.
static com.gemstone.gemfire.LogWriter	createLogWriter(String name, String filePrefix, String levelName, String dir, boolean append) Creates a singleton log writer that logs to a file in a specified directory.
static com.gemstone.gemfire.LogWriter	getLogWriter() Fetches the singleton log writer.
static String	getLogWriterLevel() Fetches the current log level of the singleton log writer.
static void	main(String[] args) Small Log test program
static void	setLogWriterLevel(String levelName) Resets the log level of the singleton log writer.
static com.gemstone.gemfire.LogWriter	uncacheLogWriter(String name) Uncaches the log writer with the specified name, blowing away the existing one (unless it was previously cached).

Methods inherited from class java.lang.Object

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

Constructor Detail

Log

public Log()

Method Detail

createLogWriter

public static com.gemstone.gemfire.LogWriter createLogWriter(String name,
                                                             String levelName)

Creates a singleton log writer that logs to stdout.

Parameters:

name - the name of the singleton log writer.

levelName - only messages at this level or higher will be logged.

Returns:

the singleton log writer.

Throws:

HydraRuntimeException - if log writer has already been created.

IllegalArgumentException - if level is illegal.

createLogWriter

public static com.gemstone.gemfire.LogWriter createLogWriter(String name,
                                                             String filePrefix,
                                                             String levelName,
                                                             boolean append)

Creates a singleton log writer that logs to a file.

Parameters:

name - the name of the singleton log writer.

filePrefix - the prefix for the name of the log file.

levelName - only messages at this level or higher will be logged.

append - whether to append to an existing log file.

Returns:

the singleton log writer.

Throws:

HydraRuntimeException - if log writer has already been created.

IllegalArgumentException - if level is illegal.

createLogWriter

public static com.gemstone.gemfire.LogWriter createLogWriter(String name,
                                                             String filePrefix,
                                                             String levelName,
                                                             String dir,
                                                             boolean append)

Creates a singleton log writer that logs to a file in a specified directory.

Parameters:

name - the name of the singleton log writer.

filePrefix - the prefix for the name of the log file.

levelName - only messages at this level or higher will be logged.

dir - the directory in which to create the log file.

append - whether to append to an existing log file.

Returns:

the singleton log writer.

Throws:

HydraRuntimeException - if log writer has already been created.

IllegalArgumentException - if level is illegal.

createLogWriter

public static com.gemstone.gemfire.LogWriter createLogWriter(String name,
                                                             String filePrefix,
                                                             boolean fileLogging,
                                                             String fileLogLevelName,
                                                             int fileMaxKBPerVM)

Creates a singleton log writer that logs to a file.

Parameters:

name - the name of the singleton log writer.

filePrefix - the prefix for files created by this log writer.

Returns:

the singleton log writer.

Throws:

HydraRuntimeException - if file can't be created or if log writer has already been created.

IllegalArgumentException - if level is illegal.

closeLogWriter

public static void closeLogWriter()

Closes the singleton log writer. After this method executes, there is no singleton log writer.

Throws:

HydraRuntimeException - if the singleton log writer does not exist.

cacheLogWriter

public static void cacheLogWriter()

Caches the singleton log writer so another log writer can be created. After this method executes, there is no singleton log writer.

Throws:

HydraRuntimeException - if the singleton log writer does not exist or has already been cached.

uncacheLogWriter

public static com.gemstone.gemfire.LogWriter uncacheLogWriter(String name)

Uncaches the log writer with the specified name, blowing away the existing one (unless it was previously cached). After this method executes, the named log writer is the singleton log writer.

Parameters:

name - the name of the log writer to uncache.

Returns:

the uncached (now active) log writer.

Throws:

HydraRuntimeException - if the named log writer does not exist or there is already a singleton log writer.

getLogWriter

public static com.gemstone.gemfire.LogWriter getLogWriter()

Fetches the singleton log writer.

Throws:

HydraRuntimeException - if log writer has not been created.

getLogWriterLevel

public static String getLogWriterLevel()

Fetches the current log level of the singleton log writer.

setLogWriterLevel

public static void setLogWriterLevel(String levelName)

Resets the log level of the singleton log writer.

main

public static void main(String[] args)

Small Log test program