com.tenduke.diagnostics
Class AbstractLogWriter

java.lang.Object
  com.tenduke.diagnostics.AbstractLogWriter

All Implemented Interfaces:

LogEntrySubscriber

Direct Known Subclasses:

ConsoleLogWriter, LogFileWriter

public abstract class AbstractLogWriter
extends java.lang.Object
implements LogEntrySubscriber

Abstract base class for log writers that listen to log entries published by a Logger and write entries to a log (log file, stdout / stderr etc.)

AbstractLogWriter uses getDebugLevel(boolean) with true input parameter as the highest debug level of a received log entry LogEntry.getDebugLevel() that is written to log. LogEntries with higher debug level are discarded.

AbstractLogWriter uses formatting templates to write each LogEntry to log. Templates can be specified for each LogEntry.getEventType(). MessageFormat is used to write log entries using this templates. Supported format specifiers are:

1. {0}: Timestamp of the log entry (printed in ISO 8601 format)
2. {1}: Event type of the log entry as string ("Error" / "Warning" / "Info")
3. {2}: Log entry debug level (number 1 - 5)
4. {3}: Log entry message
5. {4}: Message of exception attached to the log entry
6. {5}: Stack trace of exception attached to the log entry

Table of configuration keys used by this class:

Key name	Description	Default value
logging.logwriter.debug.level	Highest debug level value of received log entry that is written to log. Example: Debug level is set to 3, which means that any LogEntry with debug level set to 3 or less will be printed and LogEntry objects with debug level 4 and 5 will be omitted.	N/A
logging.logwriter.template.error	Formatting template for log entries with event type com.tenduke.diagnostics.LogEntry.EventType.Error.	N/A
logging.logwriter.template.warning	Formatting template for log entries with event type com.tenduke.diagnostics.LogEntry.EventType.Warning.	N/A
logging.logwriter.template.info	Formatting template for log entries with event type com.tenduke.diagnostics.LogEntry.EventType.Info.	N/A

Table of JVM system properties defined by this class.

System property	Description	Default value
logging.logwriter.debug.level	Highest debug level value of received log entry that is written to log. Example: Debug level is set to 3, which means that any LogEntry with debug level set to 3 or less will be printed and LogEntry objects with debug level 4 and 5 will be omitted.	5
logging.logwriter.template.error	Formatting template for log entries with event type com.tenduke.diagnostics.LogEntry.EventType.Error.	N/A
logging.logwriter.template.warning	Formatting template for log entries with event type com.tenduke.diagnostics.LogEntry.EventType.Warning.	N/A
logging.logwriter.template.info	Formatting template for log entries with event type com.tenduke.diagnostics.LogEntry.EventType.Info.	N/A

Field Summary

static int	DEFAULT_DEBUG_LEVEL Default debug level (5), if not defined in the main configuration file with a key 'logging.logwriter.debug.level'.
static java.lang.String	DEFAULT_TEMPLATE_ERROR Default print template "{1}: {3}\n{5}" for LogEntry.EventType.Error, if not defined in the main configuration file with a key 'logging.logwriter.template.error'.
static java.lang.String	DEFAULT_TEMPLATE_INFO Default print template "{1}: {3}" for LogEntry.EventType.Info, if not defined in the main configuration file with a key 'logging.logwriter.template.info'.
static java.lang.String	DEFAULT_TEMPLATE_WARNING Default print template "{1}: {3}\n{4}" for LogEntry.EventType.Warning, if not defined in the main configuration file with a key 'logging.logwriter.template.warning'.

Constructor Summary

protected

AbstractLogWriter() Initializes new instance of the AbstractLogWriter class.

Method Summary

java.lang.Integer	getDebugLevel(boolean allowDefault) Gets highest debug level of a received log entry LogEntry.getDebugLevel() that is written to log.
java.lang.String	getLogEntryTemplateError(boolean allowDefault) Gets output formatting template for error log entries.
java.lang.String	getLogEntryTemplateInfo(boolean allowDefault) Gets output formatting template for info log entries.
java.lang.String	getLogEntryTemplateWarning(boolean allowDefault) Gets output formatting template for warning log entries.
void	logEntryReceived(LogEntry entry) Method that is called for each LogEntrySubscriber by Logger when a new log entry is received.
protected abstract void	printError(LogEntry entry, java.lang.Throwable throwable) Prints error in the case that printing log entry failed.
protected void	printLogEntry(LogEntry logEntry) Prints log entry to log.
protected abstract void	printLogEntry(LogEntry logEntry, java.lang.String formatTemplate) Prints log entry to log using the given format template.
void	setDebugLevel(java.lang.Integer debugLevel) Sets highest debug level of a received log entry LogEntry.getDebugLevel() that is written to log.
void	setLogEntryTemplateError(java.lang.String logEntryTemplateError) Sets output formatting template for error log entries.
void	setLogEntryTemplateInfo(java.lang.String logEntryTemplateInfo) Sets output formatting template for info log entries.
void	setLogEntryTemplateWarning(java.lang.String logEntryTemplateWarning) Sets output formatting template for warning log entries.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_DEBUG_LEVEL

public static final int DEFAULT_DEBUG_LEVEL

Default debug level (5), if not defined in the main configuration file with a key 'logging.logwriter.debug.level'.

See Also:

Constant Field Values

DEFAULT_TEMPLATE_ERROR

public static final java.lang.String DEFAULT_TEMPLATE_ERROR

Default print template "{1}: {3}\n{5}" for LogEntry.EventType.Error, if not defined in the main configuration file with a key 'logging.logwriter.template.error'.

See Also:

Constant Field Values

DEFAULT_TEMPLATE_INFO

public static final java.lang.String DEFAULT_TEMPLATE_INFO

Default print template "{1}: {3}" for LogEntry.EventType.Info, if not defined in the main configuration file with a key 'logging.logwriter.template.info'.

See Also:

Constant Field Values

DEFAULT_TEMPLATE_WARNING

public static final java.lang.String DEFAULT_TEMPLATE_WARNING

Default print template "{1}: {3}\n{4}" for LogEntry.EventType.Warning, if not defined in the main configuration file with a key 'logging.logwriter.template.warning'.

See Also:

Constant Field Values

Constructor Detail

AbstractLogWriter

protected AbstractLogWriter()

Initializes new instance of the AbstractLogWriter class.

Method Detail

getDebugLevel

public java.lang.Integer getDebugLevel(boolean allowDefault)

Gets highest debug level of a received log entry LogEntry.getDebugLevel() that is written to log.

Parameters:

allowDefault - If true, default debug level is returned if no debug level has been explicitly set.

Returns:

Highest debug level of a received LogEntry that is written to log. Debug level value 5 means that all received log entries are written to log, 0 means that nothing is written.

getLogEntryTemplateError

public java.lang.String getLogEntryTemplateError(boolean allowDefault)

Gets output formatting template for error log entries.

Parameters:

allowDefault - If true, default template is returned if no template has been explicitly set.

Returns:

Output formatting template for error log entries.

getLogEntryTemplateInfo

public java.lang.String getLogEntryTemplateInfo(boolean allowDefault)

Gets output formatting template for info log entries.

Parameters:

allowDefault - If true, default template is returned if no template has been explicitly set.

Returns:

Output formatting template for info log entries.

getLogEntryTemplateWarning

public java.lang.String getLogEntryTemplateWarning(boolean allowDefault)

Gets output formatting template for warning log entries.

Parameters:

allowDefault - If true, default template is returned if no template has been explicitly set.

Returns:

Output formatting template for warning log entries.

logEntryReceived

public void logEntryReceived(LogEntry entry)

Method that is called for each LogEntrySubscriber by Logger when a new log entry is received.

Specified by:

logEntryReceived in interface LogEntrySubscriber

Parameters:

entry - the log entry

printError

protected abstract void printError(LogEntry entry,
                                   java.lang.Throwable throwable)

Prints error in the case that printing log entry failed.

Parameters:

entry - LogEntry for which writing failed.

throwable - The error that occurred when attempting to write.

printLogEntry

protected void printLogEntry(LogEntry logEntry)
                      throws java.io.IOException

Prints log entry to log. This method resolves format template to be used for printing the log entry and calls printLogEntry(com.tenduke.diagnostics.LogEntry, java.lang.String).

Parameters:

logEntry - LogEntry to write.

Throws:

java.io.IOException - Thrown if printing log entry to writer fails.

printLogEntry

protected abstract void printLogEntry(LogEntry logEntry,
                                      java.lang.String formatTemplate)
                               throws java.io.IOException

Prints log entry to log using the given format template.

Parameters:

logEntry - LogEntry to write.

formatTemplate - Format template to use.

Throws:

java.io.IOException - Thrown if printing log entry fails.

setDebugLevel

public void setDebugLevel(java.lang.Integer debugLevel)

Sets highest debug level of a received log entry LogEntry.getDebugLevel() that is written to log.

Parameters:

debugLevel - Highest debug level of a received LogEntry that is written to log. Debug level value 5 means that all received log entries are written to log, 0 means that nothing is written.

setLogEntryTemplateError

public void setLogEntryTemplateError(java.lang.String logEntryTemplateError)

Sets output formatting template for error log entries.

Parameters:

logEntryTemplateError - Output formatting template for error log entries.

setLogEntryTemplateInfo

public void setLogEntryTemplateInfo(java.lang.String logEntryTemplateInfo)

Sets output formatting template for info log entries.

Parameters:

logEntryTemplateInfo - Output formatting template for info log entries.

setLogEntryTemplateWarning

public void setLogEntryTemplateWarning(java.lang.String logEntryTemplateWarning)

Sets output formatting template for warning log entries.

Parameters:

logEntryTemplateWarning - Output formatting template for warning log entries.