A Spring Boot based Log4j2 starter project

Spring Boot uses Logback as a default logging solution. In order to switch to Log4j2, there are some configurations that has to be made.

The following customized configurations provide the following features:

A Maven POM for a Spring Boot starter project
Logstash layout dependency for JSon log files to feed into ELK
Log4j configuration with MDC support
Log4j configuration produces multiple log files

<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">   <modelVersion>4.0.0</modelVersion>   <parent>     <groupId>com.urcorp</groupId>     <artifactId>app-springboot-parent</artifactId>     <version>0.0.1-SNAPSHOT</version>   </parent>   <artifactId>app-log4j2-starter</artifactId>   <version>0.0.1-SNAPSHOT</version>   <name>app-log4j2-starter</name>   <description>Log4j2 starter</description>   <properties>     <log4j2-logstash-layout.version>0.19</log4j2-logstash-layout.version>   </properties>   <dependencies>     <!-- logging -->     <dependency>       <groupId>org.springframework.boot</groupId>       <artifactId>spring-boot-starter-log4j2</artifactId>     </dependency>     <!-- logstash layout -->     <dependency>       <groupId>com.vlkan.log4j2</groupId>       <artifactId>log4j2-logstash-layout</artifactId>       <version>${log4j2-logstash-layout.version}</version>     </dependency>   </dependencies>   <profiles>     <profile>       <id>local</id>       <activation>         <os>           <family>windows</family>         </os>       </activation>       <properties>         <log.file.location>C:/app/logs</log.file.location>       </properties>     </profile>     <profile>       <id>server</id>       <activation>         <os>           <family>!windows</family>         </os>       </activation>       <properties>         <log.file.location>/app/logs</log.file.location>       </properties>     </profile>   </profiles> </project>

log4j.xml

<?xml version="1.0" encoding="UTF-8"?> <Configuration xmlns:xi="http://www.w3.org/2001/XInclude" status="DEBUG" name="log4j2-ur-app" monitorInterval="30">   <Properties>     <Property name="logPath">${log.file.location}</Property>     <Property name="text.log.pattern">%d{yyyy-MM-HH:mm:ss.SSS} [%t - %X{HOSTNAME,APPLICATION,CORRELATION_ID,MESSAGE_ID}] %highlight{%level}{FATAL=bg_red, ERROR=red, WARN=yellow, INFO=green, DEBUG=blue} %c{3} - %m%n</Property>   </Properties>   <Appenders>     <Console name="console" target="SYSTEM_OUT">       <PatternLayout pattern="${text.log.pattern}" />     </Console>     <RollingFile name="serverJson" fileName="${logPath}/server.json"       filePattern="${logPath}/server_%d{yyyy-MM-dd}.%i.json">       <LogstashLayout dateTimeFormatPattern="yyyy-MM-dd'T'HH:mm:ss.SSSZZZ"         templateUri="classpath:LogstashJsonEventLayoutV1.json" prettyPrintEnabled="false" stackTraceEnabled="true" />       <xi:include href="log4j2-policies.xml" />       <xi:include href="log4j2-rolloverStrategies.xml" />     </RollingFile>     <RollingFile name="serverText" fileName="${logPath}/server.log"       filePattern="${logPath}/server_%d{yyyy-MM-dd}.log">       <PatternLayout pattern="${text.log.pattern}" />       <xi:include href="log4j2-policies.xml" />       <xi:include href="log4j2-rolloverStrategies.xml" />     </RollingFile>     <RollingFile name="exceptionText" fileName="${logPath}/exception.log"       filePattern="${logPath}/exception_%d{yyyy-MM-dd}.log">       <Filters>         <ThresholdFilter level="WARN" onMatch="ACCEPT" />       </Filters>       <PatternLayout pattern="${text.log.pattern}" />       <xi:include href="log4j2-policies.xml" />       <xi:include href="log4j2-rolloverStrategies.xml" />     </RollingFile>     <RollingFile name="eventText" fileName="${logPath}/event.log"       filePattern="${logPath}/event_%d{yyyy-MM-dd}.log">       <PatternLayout pattern="${text.log.pattern}" />       <xi:include href="log4j2-policies.xml" />       <xi:include href="log4j2-rolloverStrategies.xml" />     </RollingFile>     <RollingFile name="statsText" fileName="${logPath}/stats.log"       filePattern="${logPath}/stats_%d{yyyy-MM-dd}.log">       <PatternLayout pattern="${text.log.pattern}" />       <xi:include href="log4j2-policies.xml" />       <xi:include href="log4j2-rolloverStrategies.xml" />     </RollingFile>     <RollingFile name="perfText" fileName="${logPath}/perf.log"       filePattern="${logPath}/perf_%d{yyyy-MM-dd}.log">       <PatternLayout pattern="${text.log.pattern}" />       <xi:include href="log4j2-policies.xml" />       <xi:include href="log4j2-rolloverStrategies.xml" />     </RollingFile>     <RollingFile name="sqlText" fileName="${logPath}/sql.log"       filePattern="${logPath}/sql_%d{yyyy-MM-dd}.log">       <PatternLayout pattern="${text.log.pattern}" />       <xi:include href="log4j2-policies.xml" />       <xi:include href="log4j2-rolloverStrategies.xml" />     </RollingFile>   </Appenders>   <Loggers>     <Root level="info" additivity="false">       <AppenderRef ref="console" />       <AppenderRef ref="serverText" />       <AppenderRef ref="serverJson" />       <AppenderRef ref="exceptionText" />     </Root>     <logger name="EVENT" level="info" additivity="false">       <AppenderRef ref="eventText" />       <AppenderRef ref="console" />     </logger>     <logger name="STATISTICS" level="info" additivity="false">       <AppenderRef ref="statsText" />     </logger>     <logger name="PERFORMANCE" level="info" additivity="false">       <AppenderRef ref="perfText" />     </logger>     <logger name="SQL" level="info" additivity="false">       <AppenderRef ref="sqlText" />       <AppenderRef ref="console" />     </logger>     <logger name="com.zaxxer.hikari" level="debug" additivity="false">       <AppenderRef ref="sqlText" />     </logger>     <logger name="java.sql" level="debug" additivity="false">       <AppenderRef ref="sqlText" />     </logger>     <logger name="org.apache.ibatis" level="debug" additivity="false">       <AppenderRef ref="sqlText" />     </logger>     <logger name="org.mybatis" level="debug" additivity="false">       <AppenderRef ref="sqlText" />     </logger>     <logger name="com.urcorp.dao.generated.mapper" level="trace" additivity="false">       <AppenderRef ref="sqlText" />     </logger>     <logger name="org.springframework.jdbc.core" level="trace" additivity="true">       <AppenderRef ref="sqlText" />     </logger>   </Loggers> </Configuration>

log4j2-policies.xml

<?xml version="1.0" encoding="UTF-8"?> <Policies>   <OnStartupTriggeringPolicy />   <SizeBasedTriggeringPolicy size="300 MB" />   <TimeBasedTriggeringPolicy interval="1"     modulate="true" /> </Policies>

log4j2-rolloverStrategies.xml

<?xml version="1.0" encoding="UTF-8"?> <DefaultRolloverStrategy>   <Delete basePath="${logPath}" maxDepth="2">     <IfFileName glob="*.(json|log)" />     <IfLastModified age="7d" />   </Delete> </DefaultRolloverStrategy>

package com.urcorp.common.logging; public enum LogFileTypes {   EXCEPTION("EXCEPTION."),   EVENT("EVENT."),   PERFORMANCE("PERFORMANCE."),   SERVER("SERVER."),   SQL("SQL."),   STATISTICS("STATISTICS.");   private final String group;   private LogFileTypes(final String group) {     this.code = group;   }   public String group() {     return group;   } }