com.noveogroup.android.log

Class PatternHandler

java.lang.Object

com.noveogroup.android.log.PatternHandler

All Implemented Interfaces:

Handler

public class PatternHandler
extends Object
implements Handler

The basic implementation of Handler interface.

This log handler is configured with a logging level, a tag and a message patterns.

The logging level parameter is the minimal level of log messages printed by this handler instance. The logging level can be null which means no messages should be printed using this logger.

Attention: Android may set its own requirement for logging level using Log#isLoggable(String, int) method. This logger doesn't take it into account in isEnabled(Logger.Level) method.

The patterns are format strings written according to a special rules described below. Log messages will be formatted and printed as it is specified in the tag and the message pattern. The tag pattern configures log tag used to print messages. The message pattern configures a head of the message but not whole message printed to log.

The tag pattern	TAG
The message pattern	%d{yyyy-MM-dd}:
Resulting tag	TAG
Resulting message	2013-07-12: <incoming message>

The tag and the message patterns are wrote according to similar rules. So we will show only one pattern in further examples.

The patterns is strings that contains a set of placeholders and other special marks. Each special mark should start with '%' sign. To escape this sign you can double it.

The list of special marks and placeholders:

Conversion marks

Mark	Effect
%%	Escapes special sign. Prints just one '%' instead.
%n	Prints a new line character '\n'.
%d{date format} %date{date format}	Prints date/time of a message. Date format should be supported by SimpleDateFormat. Default date format is "yyyy-MM-dd HH:mm:ss.SSS".
%p %level	Prints logging level of a message.
%c{count.length} %logger{count.length}	Prints a name of the logger. The algorithm will shorten some part of full logger name to the specified length. You can find examples below. Conversion specifier Logger name Result %logger com.example.android.MainActivity com.example.android.MainActivity %logger{0} com.example.android.MainActivity com.example.android.MainActivity %logger{3} com.example.android.MainActivity com.example.android %logger{-1} com.example.android.MainActivity example.android.MainActivity %logger{.0} com.example.android.MainActivity com.example.android.MainActivity %logger{.30} com.example.android.MainActivity com.example.android.* %logger{.15} com.example.android.MainActivity com.example.* %logger{.-25} com.example.android.MainActivity *.android.MainActivity %logger{3.-18} com.example.android.MainActivity *.example.android %logger{-3.-10} com.example.android.MainActivity$SubClass MainActivity$SubClass
%C{count.length} %caller{count.length}	Prints information about a caller class which causes the logging event. Additional parameters 'count' and 'length' means the same as the parameters of %logger. Examples: Conversion specifier Caller Result %caller Class com.example.android.MainActivity at line 154 com.example.android.MainActivity:154 %caller{-3.-15} Class com.example.android.MainActivity at line 154 MainActivity:154
%s{count.length} %source{count.length}	Prints source of class which causes the logging event. Examples: Conversion specifier Caller Result %source or %s Class com.example.android.MainActivity at line 154 (MainActivity.java:154) %source or %s Native (native) %source or %s Unknown (unknown)
%t{count.length} %thread{count.length}	Prints a name of the thread which causes the logging event.
%(...)	Special mark used to grouping parts of message. Format modifiers (if specified) are applied on whole group. Examples: Example Result [%50(%d %caller{-3.-15})] [ 2013-07-12 19:45:26.315 MainActivity:154] [%-50(%d %caller{-3.-15})] [2013-07-12 19:45:26.315 MainActivity:154 ]

After special sign '%' user can add format modifiers. The modifiers is similar to standard modifiers of Formatter conversions.

Example	Result
%6(text)	' text'
%-6(text)	'text '
%.3(text)	'tex'
%.-3(text)	'ext'

Constructor Summary

Constructors

Constructor and Description
PatternHandler(Logger.Level level, String tagPattern, String messagePattern) Creates new PatternHandler.

Method Summary

Methods

Modifier and Type	Method and Description
Logger.Level	getLevel() Returns the level.
String	getMessagePattern() Returns the message messagePattern.
String	getTagPattern() Returns the tag messagePattern.
boolean	isEnabled(Logger.Level level) Checks if the specified log level is enabled or not for this handler.
void	print(String loggerName, Logger.Level level, Throwable throwable, String message) Prints a log message.
void	print(String loggerName, Logger.Level level, Throwable throwable, String messageFormat, Object... args) Prints a log message.

Methods inherited from class java.lang.Object

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

Constructor Detail

PatternHandler

public PatternHandler(Logger.Level level,
              String tagPattern,
              String messagePattern)

Creates new PatternHandler.

Parameters:

level - the level.

tagPattern - the tag pattern.

messagePattern - the message pattern.

Method Detail

getLevel

public Logger.Level getLevel()

Returns the level.

Returns:

the level.

getTagPattern

public String getTagPattern()

Returns the tag messagePattern.

Returns:

the tag messagePattern.

getMessagePattern

public String getMessagePattern()

Returns the message messagePattern.

Returns:

the message messagePattern.

isEnabled

public boolean isEnabled(Logger.Level level)

Description copied from interface: Handler

Checks if the specified log level is enabled or not for this handler.

Specified by:

isEnabled in interface Handler

Parameters:

level - the level.

Returns:

Are messages with this level allowed to be logged or not.

print

public void print(String loggerName,
         Logger.Level level,
         Throwable throwable,
         String message)
           throws IllegalArgumentException

Description copied from interface: Handler

Prints a log message.

This method should automatically check using Handler.isEnabled(Logger.Level) method if the message is allowed to be logged or not.

Specified by:

print in interface Handler

Parameters:

loggerName - a name of a logger that user used to log message.

level - a level of the log message

throwable - a throwable object or null.

message - a log message. Can be null.

Throws:

IllegalArgumentException - if no format string is specified but arguments are presented.

print

public void print(String loggerName,
         Logger.Level level,
         Throwable throwable,
         String messageFormat,
         Object... args)
           throws IllegalArgumentException

Description copied from interface: Handler

Prints a log message.

This method should automatically check using Handler.isEnabled(Logger.Level) method if the message is allowed to be logged or not.

The format string of the log message should be formatted according to rules of the standard format string described in JavaDoc of Formatter. Implementations can use Formatter.format(String, Object...) to prepare the log message from format string and array of arguments.

Specified by:

print in interface Handler

Parameters:

loggerName - a name of a logger that user used to log message.

level - a level of the log message

throwable - a throwable object or null.

messageFormat - a format string of the log message. Can be null.

args - an array of arguments. Can be null which is considered as an empty array.

Throws:

IllegalArgumentException - if no format string is specified but arguments are presented.