Log4j Pattern Layout: Difference between revisions
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===Conversion Character=== | ===Conversion Character=== | ||
The ''conversion character'' specifies the type of data | The ''conversion character'' specifies the type of data. | ||
===='c' Category (or Logger)==== | |||
c{precision} | c{precision} | ||
===='d' Date==== | |||
d | |||
===='m' Message=== | |||
Application supplied message associated with this log event. | |||
m | |||
===='n'===== | |||
Platform dependent line separator. | |||
n | |||
===='p' Level==== | |||
The level of the logging event: | |||
p | |||
===='t' Thread Name==== | |||
t | |||
=Throwable Handling= | =Throwable Handling= | ||
If the pattern string does not contain a specifier to handle a Throwable being logged, parsing of the pattern will act as if the "%xEx" specifier had been added to the end of the string. To suppress formatting of the Throwable completely, simply add "%ex{0}" as a specifier in the pattern string. | If the pattern string does not contain a specifier to handle a Throwable being logged, parsing of the pattern will act as if the "%xEx" specifier had been added to the end of the string. To suppress formatting of the Throwable completely, simply add "%ex{0}" as a specifier in the pattern string. | ||
Revision as of 20:05, 15 November 2017
External
Internal
Overview
The pattern layout is defined by a conversion pattern string.
Conversion Pattern
The conversion pattern string specifies the various elements of a log event and the way they are intended to be displayed in a log file. The conversion pattern is closely related to the conversion pattern of the printf function in C. The conversion pattern is composed of:
There is no explicit separator between literal text and conversion specifiers. The pattern parser knows when it has reached the end of a conversion specifier when it reads a conversion character.
Literal Text
Literal text may include special characters (\t, \n \r \f). '\\' can be used to insert a backslash in the output.
Conversion Specifier
Each conversion specifier starts with a percent sign ('%') and it is followed by an optional format modifier and a mandatory conversion character:
%-5c
Format Modifier
A format modifier modifies how the data generated by the conversion specifier is displayed: field with, padding and justification.
Conversion Character
The conversion character specifies the type of data.
'c' Category (or Logger)
c{precision}
'd' Date
d
='m' Message
Application supplied message associated with this log event.
m
'n'=
Platform dependent line separator.
n
'p' Level
The level of the logging event:
p
't' Thread Name
t
Throwable Handling
If the pattern string does not contain a specifier to handle a Throwable being logged, parsing of the pattern will act as if the "%xEx" specifier had been added to the end of the string. To suppress formatting of the Throwable completely, simply add "%ex{0}" as a specifier in the pattern string.