Log4j2 之Patterns配置

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最新推荐文章于 2025-03-25 14:53:36 发布

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原文链接：http://www.cnblogs.com/8341-jack/p/9830126.html

本文详细介绍了Log4j2中PatternLayout的配置参数及转换模式，包括字符集、模式字符串、正则表达式替换等，以及如何使用各种转换模式如日期、异常堆栈、线程信息等。

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Log4j2 之Patterns配置

参见 https://logging.apache.org/log4j/2.x/manual/layouts.html#PatternLayout

PatternLayout Parameters
Parameter Name	Type	Description
charset	String	The character set to use when converting the syslog String to a byte array. The String must be a valid Charset. If not specified, this layout uses the platform default character set.
pattern	String	A composite pattern string of one or more conversion patterns from the table below. Cannot be specified with a PatternSelector.
patternSelector	PatternSelector	A component that analyzes information in the LogEvent and determines which pattern should be used to format the event. The pattern and patternSelector parameters are mutually exclusive.
replace	RegexReplacement	Allows portions of the resulting String to be replaced. If configured, the replace element must specify the regular expression to match and the substitution. This performs a function similar to the RegexReplacement converter but applies to the whole message while the converter only applies to the String its pattern generates.
alwaysWriteExceptions	boolean	If `true` (it is by default) exceptions are always written even if the pattern contains no exception conversions. This means that if you do not include a way to output exceptions in your pattern, the default exception formatter will be added to the end of the pattern. Setting this to `false` disables this behavior and allows you to exclude exceptions from your pattern output.
header	String	The optional header string to include at the top of each log file.
footer	String	The optional footer string to include at the bottom of each log file.
disableAnsi	boolean	If `true` (default is false), do not output ANSI escape codes.
noConsoleNoAnsi	boolean	If `true` (default is false) and `System.console()` is null, do not output ANSI escape codes.

Conversion Pattern Description

c{precision}
logger{precision}

Outputs the name of the logger that published the logging event. The logger conversion specifier can be optionally followed by precision specifier, which consists of a decimal integer, or a pattern starting with a decimal integer.

When the precision specifier is an integer value, it reduces the size of the logger name. If the number is positive, the layout prints the corresponding number of rightmost logger name components. If negative, the layout removes the corresponding number of leftmost logger name components.

If the precision contains any non-integer characters, then the layout abbreviates the name based on the pattern. If the precision integer is less than one, the layout still prints the right-most token in full. By default, the layout prints the logger name in full.

Conversion Pattern	Logger Name	Result
%c{1}	org.apache.commons.Foo	Foo
%c{2}	org.apache.commons.Foo	commons.Foo
%c{10}	org.apache.commons.Foo	org.apache.commons.Foo
%c{-1}	org.apache.commons.Foo	apache.commons.Foo
%c{-2}	org.apache.commons.Foo	commons.Foo
%c{-10}	org.apache.commons.Foo	org.apache.commons.Foo
%c{1.}	org.apache.commons.Foo	o.a.c.Foo
%c{1.1.~.~}	org.apache.commons.test.Foo	o.a.~.~.Foo
%c{.}	org.apache.commons.test.Foo	....Foo

C{precision}
class{precision}

Outputs the fully qualified class name of the caller issuing the logging request. This conversion specifier can be optionally followed by precision specifier, that follows the same rules as the logger name converter.

Generating the class name of the caller (location information) is an expensive operation and may impact performance. Use with caution.

d{pattern}
date{pattern}

Outputs the date of the logging event. The date conversion specifier may be followed by a set of braces containing a date and time pattern string per SimpleDateFormat .

The predefined formats are DEFAULT, ABSOLUTE, COMPACT, DATE, ISO8601, and ISO8601_BASIC.

You can also use a set of braces containing a time zone id per java.util.TimeZone.getTimeZone. If no date format specifier is given then the DEFAULT format is used.

Pattern	Example
%d{DEFAULT}	2012-11-02 14:34:02,123
%d{DEFAULT_MICROS}	2012-11-02 14:34:02,123456
%d{DEFAULT_NANOS}	2012-11-02 14:34:02,123456789
%d{ISO8601}	2012-11-02T14:34:02,781
%d{ISO8601_BASIC}	20121102T143402,781
%d{ABSOLUTE}	14:34:02,781
%d{ABSOLUTE_MICROS}	14:34:02,123456
%d{ABSOLUTE_NANOS}	14:34:02,123456789
%d{DATE}	02 Nov 2012 14:34:02,781
%d{COMPACT}	20121102143402781
%d{HH:mm:ss,SSS}	14:34:02,123
%d{HH:mm:ss,nnnn} to %d{HH:mm:ss,nnnnnnnnn}	14:34:02,1234 to 14:34:02,123456789
%d{dd MMM yyyy HH:mm:ss,SSS}	02 Nov 2012 14:34:02,123
%d{dd MMM yyyy HH:mm:ss,nnnn} to %d{dd MMM yyyy HH:mm:ss,nnnnnnnnn}	02 Nov 2012 14:34:02,1234 to 02 Nov 2012 14:34:02,123456789
%d{HH:mm:ss}{GMT+0}	18:34:02
%d{UNIX}	1351866842
%d{UNIX_MILLIS}	1351866842781

%d{UNIX} outputs the UNIX time in seconds. %d{UNIX_MILLIS} outputs the UNIX time in milliseconds. The UNIX time is the difference, in seconds for UNIX and in milliseconds for UNIX_MILLIS, between the current time and midnight, January 1, 1970 UTC. While the time unit is milliseconds, the granularity depends on the operating system (Windows). This is an efficient way to output the event time because only a conversion from long to String takes place, there is no Date formatting involved.

Log4j 2.11 adds limited support for timestamps more precise than milliseconds when running on Java 9. Note that not all DateTimeFormatter formats are supported. Only timestamps in the formats mentioned in the table above may use the "nano-of-second" pattern letter n instead of the "fraction-of-second" pattern letter S.

Users may revert back to a millisecond-precision clock when running on Java 9 by setting system property log4j2.Clock to SystemMillisClock.

enc{pattern}{[HTML|XML|JSON|CRLF]}
encode{pattern}{[HTML|XML|JSON|CRLF]}

Encodes and escapes special characters suitable for output in specific markup languages. By default, this encodes for HTML if only one option is specified. The second option is used to specify which encoding format should be used. This converter is particularly useful for encoding user provided data so that the output data is not written improperly or insecurely.

A typical usage would encode the message %enc{%m} but user input could come from other locations as well, such as the MDC %enc{%mdc{key}}

Using the HTML encoding format, the following characters are replaced:

Character	Replacement
'\r', '\n'	Converted into escaped strings "\\r" and "\\n" respectively
&, <, >, ", ', /	Replaced with the corresponding HTML entity

Using the XML encoding format, this follows the escaping rules specified by the XML specification:

Character	Replacement
&, <, >, ", '	Replaced with the corresponding XML entity

Using the JSON encoding format, this follows the escaping rules specified by RFC 4627 section 2.5:

Character	Replacement
U+0000 - U+001F	\u0000 - \u001F
Any other control characters	Encoded into its `\uABCD` equivalent escaped code point
"	\"
\	\\

For example, the pattern {"message": "%enc{%m}{JSON}"} could be used to output a valid JSON document containing the log message as a string value.

Using the CRLF encoding format, the following characters are replaced:

Character	Replacement
'\r', '\n'	Converted into escaped strings "\\r" and "\\n" respectively

equals{pattern}{test}{substitution}
equalsIgnoreCase{pattern}{test}{substitution}

Replaces occurrences of 'test', a string, with its replacement 'substitution' in the string resulting from evaluation of the pattern. For example, "%equals{[%marker]}{[]}{}" will replace '[]' strings produces by events without markers with an empty string.

The pattern can be arbitrarily complex and in particular can contain multiple conversion keywords.

ex|exception|throwable
{
  [ "none"
   | "full"
   | depth
   | "short"
   | "short.className"
   | "short.fileName"
   | "short.lineNumber"
   | "short.methodName"
   | "short.message"
   | "short.localizedMessage"]
}
  {filters(package,package,...)}
  {suffix(pattern)}
  {separator(separator)}

Outputs the Throwable trace bound to the logging event, by default this will output the full trace as one would normally find with a call to Throwable.printStackTrace().

You can follow the throwable conversion word with an option in the form %throwable{option}.

%throwable{short} outputs the first line of the Throwable.

%throwable{short.className} outputs the name of the class where the exception occurred.

%throwable{short.methodName} outputs the method name where the exception occurred.

%throwable{short.fileName} outputs the name of the class where the exception occurred.

%throwable{short.lineNumber} outputs the line number where the exception occurred.

%throwable{short.message} outputs the message.

%throwable{short.localizedMessage} outputs the localized message.

%throwable{n} outputs the first n lines of the stack trace.

Specifying %throwable{none} or %throwable{0} suppresses output of the exception.

Use {filters(packages)} where packages is a list of package names to suppress matching stack frames from stack traces.

Use {suffix(pattern)} to add the output of pattern at the end of each stack frames.

Use a {separator(...)} as the end-of-line string. For example: separator(|). The default value is the line.separator system property, which is operating system dependent.

F
file

Outputs the file name where the logging request was issued.

Generating the file information (location information) is an expensive operation and may impact performance. Use with caution.

highlight{pattern}{style}

Adds ANSI colors to the result of the enclosed pattern based on the current event's logging level. (See Jansi configuration.)

The default colors for each level are:

Level	ANSI color
FATAL	Bright red
ERROR	Bright red
WARN	Yellow
INFO	Green
DEBUG	Cyan
TRACE	Black (looks dark grey)

The color names are ANSI names defined in the AnsiEscape class.

The color and attribute names and are standard, but the exact shade, hue, or value.

Color table
Intensity Code	0	1	2	3	4	5	6	7
Normal	Black	Red	Green	Yellow	Blue	Magenta	Cyan	White
Bright	Black	Red	Green	Yellow	Blue	Magenta	Cyan	White

You can use the default colors with:

%highlight{%d [%t] %-5level: %msg%n%throwable}

You can override the default colors in the optional {style} option. For example:

%highlight{%d [%t] %-5level: %msg%n%throwable}{FATAL=white, ERROR=red, WARN=blue, INFO=black, DEBUG=green, TRACE=blue}

You can highlight only the a portion of the log event:

%d [%t] %highlight{%-5level: %msg%n%throwable}

You can style one part of the message and highlight the rest the log event:

%style{%d [%t]}{black} %highlight{%-5level: %msg%n%throwable}

You can also use the STYLE key to use a predefined group of colors:

%highlight{%d [%t] %-5level: %msg%n%throwable}{STYLE=Logback}

The STYLE value can be one of:

Style

Description

Default

See above

Logback

Level	ANSI color
FATAL	Blinking bright red
ERROR	Bright red
WARN	Red
INFO	Blue
DEBUG	Normal
TRACE	Normal

K{key}
map{key}
MAP{key}

Outputs the entries in a MapMessage, if one is present in the event. The K conversion character can be followed by the key for the map placed between braces, as in %K{clientNumber} where clientNumber is the key. The value in the Map corresponding to the key will be output. If no additional sub-option is specified, then the entire contents of the Map key value pair set is output using a format {{key1,val1},{key2,val2}}

l
location

Outputs location information of the caller which generated the logging event.

The location information depends on the JVM implementation but usually consists of the fully qualified name of the calling method followed by the callers source the file name and line number between parentheses.

Generating location information is an expensive operation and may impact performance. Use with caution.

L
line

Outputs the line number from where the logging request was issued.

Generating line number information (location information) is an expensive operation and may impact performance. Use with caution.

m{nolookups}{ansi}
msg{nolookups}{ansi}
message{nolookups}{ansi}

Outputs the application supplied message associated with the logging event.

Add {ansi} to render messages with ANSI escape codes (requires JAnsi, see configuration.)

The default syntax for embedded ANSI codes is:

@|code(,code)*text|@

For example, to render the message "Hello" in green, use:

@|green Hello|@

To render the message "Hello" in bold and red, use:

@|bold,red Warning!|@

You can also define custom style names in the configuration with the syntax:

%message{ansi}{StyleName=value(,value)*(StyleName=value(,value)*)*}%n

For example:

%message{ansi}{WarningStyle=red,bold KeyStyle=white ValueStyle=blue}%n

The call site can look like this:

logger.info("@|KeyStyle {}|@ = @|ValueStyle {}|@", entry.getKey(), entry.getValue());

Use {nolookups} to log messages like "${date:YYYY-MM-dd}" without using any lookups. Normally calling logger.info("Try ${date:YYYY-MM-dd}") would replace the date template ${date:YYYY-MM-dd} with an actual date. Using nolookups disables this feature and logs the message string untouched.

M
method

Outputs the method name where the logging request was issued.

Generating the method name of the caller (location information) is an expensive operation and may impact performance. Use with caution.

marker The full name of the marker, including parents, if one is present.

markerSimpleName The simple name of the marker (not including parents), if one is present.

maxLen
maxLength

Outputs the result of evaluating the pattern and truncating the result. If the length is greater than 20, then the output will contain a trailing ellipsis. If the provided length is invalid, a default value of 100 is used.

Example syntax: %maxLen{%p: %c{1} - %m%notEmpty{ =>%ex{short}}}{160} will be limited to 160 characters with a trailing ellipsis. Another example: %maxLen{%m}{20} will be limited to 20 characters and no trailing ellipsis.

Outputs the platform dependent line separator character or characters.

This conversion character offers practically the same performance as using non-portable line separator strings such as "\n", or "\r\n". Thus, it is the preferred way of specifying a line separator.

N
nano

Outputs the result of System.nanoTime() at the time the log event was created.

pid{[defaultValue]}
processId{[defaultValue]}

Outputs the process ID if supported by the underlying platform. An optional default value may be specified to be shown if the platform does not support process IDs.

variablesNotEmpty{pattern}
varsNotEmpty{pattern}
notEmpty{pattern}

Outputs the result of evaluating the pattern if and only if all variables in the pattern are not empty.

For example:

%notEmpty{[%marker]}

p|level{level=label, level=label, ...} p|level{length=n} p|level{lowerCase=true|false}

Outputs the level of the logging event. You provide a level name map in the form "level=value, level=value" where level is the name of the Level and value is the value that should be displayed instead of the name of the Level.

For example:

%level{WARN=Warning, DEBUG=Debug, ERROR=Error, TRACE=Trace, INFO=Info}

Alternatively, for the compact-minded:

%level{WARN=W, DEBUG=D, ERROR=E, TRACE=T, INFO=I}

More succinctly, for the same result as above, you can define the length of the level label:

%level{length=1}

If the length is greater than a level name length, the layout uses the normal level name.

You can combine the two kinds of options:

%level{ERROR=Error, length=2}

This give you the Error level name and all other level names of length 2.

Finally, you can output lower-case level names (the default is upper-case):

%level{lowerCase=true}

r
relative Outputs the number of milliseconds elapsed since the JVM was started until the creation of the logging event.

replace{pattern}{regex}{substitution}

Replaces occurrences of 'regex', a regular expression, with its replacement 'substitution' in the string resulting from evaluation of the pattern. For example, "%replace{%msg}{\s}{}" will remove all spaces contained in the event message.

The pattern can be arbitrarily complex and in particular can contain multiple conversion keywords. For instance, "%replace{%logger %msg}{\.}{/}" will replace all dots in the logger or the message of the event with a forward slash.

rEx|rException|rThrowable
  {
    ["none" | "short" | "full" | depth]
    [,filters(package,package,...)]
    [,separator(separator)]
  }
  {ansi(
    Key=Value,Value,...
    Key=Value,Value,...
    ...)
  }
  {suffix(pattern)}

The same as the %throwable conversion word but the stack trace is printed starting with the first exception that was thrown followed by each subsequent wrapping exception.

The throwable conversion word can be followed by an option in the form %rEx{short} which will only output the first line of the Throwable or %rEx{n} where the first n lines of the stack trace will be printed.

Specifying %rEx{none} or %rEx{0} will suppress printing of the exception.

Use filters(packages) where packages is a list of package names to suppress matching stack frames from stack traces.

Use a separator string to separate the lines of a stack trace. For example: separator(|). The default value is the line.separator system property, which is operating system dependent.

Use rEx{suffix(pattern) to add the output of pattern to the output only when there is a throwable to print.

sn
sequenceNumber Includes a sequence number that will be incremented in every event. The counter is a static variable so will only be unique within applications that share the same converter Class object.

style{pattern}{ANSI style}

Uses ANSI escape sequences to style the result of the enclosed pattern. The style can consist of a comma separated list of style names from the following table. (See Jansi configuration.)

Style Name	Description
Normal	Normal display
Bright	Bold
Dim	Dimmed or faint characters
Underline	Underlined characters
Blink	Blinking characters
Reverse	Reverse video
Hidden
Black or FG_Black	Set foreground color to black
Red or FG_Red	Set foreground color to red
Green or FG_Green	Set foreground color to green
Yellow or FG_Yellow	Set foreground color to yellow
Blue or FG_Blue	Set foreground color to blue
Magenta or FG_Magenta	Set foreground color to magenta
Cyan or FG_Cyan	Set foreground color to cyan
White or FG_White	Set foreground color to white
Default or FG_Default	Set foreground color to default (white)
BG_Black	Set background color to black
BG_Red	Set background color to red
BG_Green	Set background color to green
BG_Yellow	Set background color to yellow
BG_Blue	Set background color to blue
BG_Magenta	Set background color to magenta
BG_Cyan	Set background color to cyan
BG_White	Set background color to white

For example:

%style{%d{ISO8601}}{black} %style{[%t]}{blue} %style{%-5level:}{yellow} %style{%msg%n%throwable}{green}

You can also combine styles:

%d %highlight{%p} %style{%logger}{bright,cyan} %C{1.} %msg%n

You can also use % with a color like %black, %blue, %cyan, and so on. For example:

%black{%d{ISO8601}} %blue{[%t]} %yellow{%-5level:} %green{%msg%n%throwable}

T
tid
threadId Outputs the ID of the thread that generated the logging event.

t
tn
thread
threadName Outputs the name of the thread that generated the logging event.

tp
threadPriority Outputs the priority of the thread that generated the logging event.

fqcn Outputs the fully qualified class name of the logger.

endOfBatch Outputs the EndOfBatch status of the logging event, as "true" or "false".

x
NDC Outputs the Thread Context Stack (also known as the Nested Diagnostic Context or NDC) associated with the thread that generated the logging event.

X{key[,key2...]}
mdc{key[,key2...]}
MDC{key[,key2...]}

Outputs the Thread Context Map (also known as the Mapped Diagnostic Context or MDC) associated with the thread that generated the logging event. The X conversion character can be followed by one or more keys for the map placed between braces, as in %X{clientNumber} where clientNumber is the key. The value in the MDC corresponding to the key will be output.

If a list of keys are provided, such as %X{name, number}, then each key that is present in the ThreadContext will be output using the format {name=val1, number=val2}. The key/value pairs will be printed in the order they appear in the list.

If no sub-options are specified then the entire contents of the MDC key value pair set is output using a format {key1=val1, key2=val2}. The key/value pairs will be printed in sorted order.

See the ThreadContext class for more details.

u{"RANDOM" | "TIME"}
uuid Includes either a random or a time-based UUID. The time-based UUID is a Type 1 UUID that can generate up to 10,000 unique ids per millisecond, will use the MAC address of each host, and to try to insure uniqueness across multiple JVMs and/or ClassLoaders on the same host a random number between 0 and 16,384 will be associated with each instance of the UUID generator Class and included in each time-based UUID generated. Because time-based UUIDs contain the MAC address and timestamp they should be used with care as they can cause a security vulnerability.

xEx|xException|xThrowable
  {
    ["none" | "short" | "full" | depth]
    [,filters(package,package,...)]
    [,separator(separator)]
  }
  {ansi(
    Key=Value,Value,...
    Key=Value,Value,...
    ...)
  }
  {suffix(pattern)}

The same as the %throwable conversion word but also includes class packaging information.

At the end of each stack element of the exception, a string containing the name of the jar file that contains the class or the directory the class is located in and the "Implementation-Version" as found in that jar's manifest will be added. If the information is uncertain, then the class packaging data will be preceded by a tilde, i.e. the '~' character.

The throwable conversion word can be followed by an option in the form %xEx{short} which will only output the first line of the Throwable or %xEx{n} where the first n lines of the stack trace will be printed. Specifying %xEx{none} or %xEx{0} will suppress printing of the exception.

Use filters(packages) where packages is a list of package names to suppress matching stack frames from stack traces.

Use a separator string to separate the lines of a stack trace. For example: separator(|). The default value is the line.separator system property, which is operating system dependent.

The ansi option renders stack traces with ANSI escapes code using the JAnsi library. (See configuration.) Use {ansi} to use the default color mapping. You can specify your own mappings with key=value pairs. The keys are: