logger.info("Ignored", value1, value2, value3);

value1, value2, value3

logger.info(new ObjectArrayMessage(value1, value2, value3));

logger.debug("one={}, two={}, three={}", 1, 2, 3);

0,1441617184044,DEBUG,main,"one=1, two=2, three=3",org.apache.logging.log4j.spi.AbstractLogger,,,,org.apache.logging.log4j.core.layout.CsvLogEventLayoutTest.testLayout(CsvLogEventLayoutTest.java:98),{},[]

  <Appenders>
    <Socket name="Graylog" protocol="udp" host="graylog.domain.com" port="12201">
        <GelfLayout host="someserver" compressionType="ZLIB" compressionThreshold="1024"/>
    </Socket>
  </Appenders>

  <Appenders>
    <Socket name="Graylog" protocol="tcp" host="graylog.domain.com" port="12201">
        <GelfLayout host="someserver" compressionType="OFF" includeNullDelimiter="true"/>
    </Socket>
  </Appenders>

<GelfLayout includeThreadContext="true" threadContextIncludes="loginId,requestId">
    <MessagePattern>%d %5p [%t] %c{1} %X{loginId, requestId} - %m%n</MessagePattern>
    <KeyValuePair key="additionalField1" value="constant value"/>
    <KeyValuePair key="additionalField2" value="$${ctx:key}"/>
</GelfLayout>

<Appenders>
  <Console name="console">
    <HtmlLayout datePattern="ISO8601" timezone="GMT+0"/>
  </Console>
</Appenders>

{
  "mdc": {
    "$resolver": "mdc"
  },
  "exception": {
    "exception_class": {
      "$resolver": "exception",
      "field": "className"
    },
    "exception_message": {
      "$resolver": "exception",
      "field": "message"
    },
    "stacktrace": {
      "$resolver": "exception",
      "field": "stackTrace",
      "stackTrace": {
        "stringified": true
      }
    }
  },
  "line_number": {
    "$resolver": "source",
    "field": "lineNumber"
  },
  "class": {
    "$resolver": "source",
    "field": "className"
  },
  "@version": 1,
  "source_host": "${hostName}",
  "message": {
    "$resolver": "message",
    "stringified": true
  },
  "thread_name": {
    "$resolver": "thread",
    "field": "name"
  },
  "@timestamp": {
    "$resolver": "timestamp"
  },
  "level": {
    "$resolver": "level",
    "field": "name"
  },
  "file": {
    "$resolver": "source",
    "field": "fileName"
  },
  "method": {
    "$resolver": "source",
    "field": "methodName"
  },
  "logger_name": {
    "$resolver": "logger",
    "field": "name"
  }
}

<JsonTemplateLayout eventTemplateUri="classpath:LogstashJsonEventLayoutV1.json"/>

{
  "exception": {
    "exception_class": "java.lang.RuntimeException",
    "exception_message": "test",
    "stacktrace": "java.lang.RuntimeException: test\n\tat org.apache.logging.log4j.JsonTemplateLayoutDemo.main(JsonTemplateLayoutDemo.java:11)\n"
  },
  "line_number": 12,
  "class": "org.apache.logging.log4j.JsonTemplateLayoutDemo",
  "@version": 1,
  "source_host": "varlik",
  "message": "Hello, error!",
  "thread_name": "main",
  "@timestamp": "2017-05-25T19:56:23.370+02:00",
  "level": "ERROR",
  "file": "JsonTemplateLayoutDemo.java",
  "method": "main",
  "logger_name": "org.apache.logging.log4j.JsonTemplateLayoutDemo"
}

Logger logger = LogManager.getLogger("MyLogger");
logger.debug("Message 1");
logger.warn("Message 2");

DEBUG [main]: Message 1
WARN  [main]: Message 2

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

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

%highlight{%d [%t] %-5level: %msg%n%throwable}{FATAL=white, ERROR=red, WARN=bg_#5792e6 fg_#eef26b bold, INFO=black, DEBUG=#3fe0a8, TRACE=blue}

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

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

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

@|code(,code)* text|@

@|green Hello|@

@|bold,red Warning!|@

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

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

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

%notEmpty{[%marker]}

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

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

%level{length=1}

%level{ERROR=Error, length=2}

%level{lowerCase=true}

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

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

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

<properties>
  <property name="filters">org.junit,org.apache.maven,sun.reflect,java.lang.reflect</property>
</properties>
...
<PatternLayout pattern="%m%xEx{filters(${filters})}%n"/>

Exception java.lang.IllegalArgumentException: IllegalArgument
at org.apache.logging.log4j.core.pattern.ExtendedThrowableTest.testException(ExtendedThrowableTest.java:72) [test-classes/:?]
... suppressed 26 lines
at $Proxy0.invoke(Unknown Source)} [?:?]
... suppressed 3 lines
Caused by: java.lang.NullPointerException: null pointer
at org.apache.logging.log4j.core.pattern.ExtendedThrowableTest.testException(ExtendedThrowableTest.java:71) ~[test-classes/:?]
... 30 more

<PatternLayout>
  <pattern>%d %highlight{%p} %style{%C{1.} [%t] %m}{bold,green}%n</pattern>
</PatternLayout>

<PatternLayout>
  <MarkerPatternSelector defaultPattern="[%-5level] %c{1.} %msg%n">
    <PatternMatch key="FLOW" pattern="[%-5level] %c{1.} ====== %C{1.}.%M:%L %msg ======%n"/>
  </MarkerPatternSelector>
</PatternLayout>

<PatternLayout>
  <ScriptPatternSelector defaultPattern="[%-5level] %c{1.} %C{1.}.%M.%L %msg%n">
    <Script name="BeanShellSelector" language="bsh"><![CDATA[
      if (logEvent.getLoggerName().equals("NoLocation")) {
        return "NoLocation";
      } else if (logEvent.getMarker() != null && logEvent.getMarker().isInstanceOf("FLOW")) {
        return "Flow";
      } else {
        return null;
      }]]>
    </Script>
    <PatternMatch key="NoLocation" pattern="[%-5level] %c{1.} %msg%n"/>
    <PatternMatch key="Flow" pattern="[%-5level] %c{1.} ====== %C{1.}.%M:%L %msg ======%n"/>
  </ScriptPatternSelector>
</PatternLayout>

---
instant:
 epochSecond: 1493121664
 nanoOfSecond: 118000000
thread: "main"
level: "INFO"
loggerName: "HelloWorld"
marker:
 name: "child"
 parents:
 - name: "parent"
   parents:
   - name: "grandparent"
message: "Hello, world!"
thrown:
 commonElementCount: 0
 message: "error message"
 name: "java.lang.RuntimeException"
 extendedStackTrace:
 - class: "logtest.Main"
   method: "main"
   file: "Main.java"
   line: 29
   exact: true
   location: "classes/"
   version: "?"
contextStack:
- "one"
- "two"
endOfBatch: false
loggerFqcn: "org.apache.logging.log4j.spi.AbstractLogger"
contextMap:
 bar: "BAR"
 foo: "FOO"
threadId: 1
threadPriority: 5
source:
 class: "logtest.Main"
 method: "main"
 file: "Main.java"
 line: 29

  <YamlLayout>
    <KeyValuePair key="additionalField1" value="constant value"/>
    <KeyValuePair key="additionalField2" value="$${ctx:key}"/>
  </YamlLayout>