log4j2 ERROR StatusLogger Unrecognized conversion specifier

Question

I have log4j2 in my project when I run main method in intellij Idea ,it correct to print log.

when i use maven-shade-plugin package project to jar file, and run jar as standalone application it shows error:

java -cp package.jar com.xxx.TestMain

the console output

ERROR StatusLogger Unrecognized format specifier [d] ERROR StatusLogger Unrecognized conversion specifier [d] starting at position 16 in conversion pattern. ERROR StatusLogger Unrecognized format specifier [thread] ERROR StatusLogger Unrecognized conversion specifier [thread] starting at position 25 in conversion pattern. ERROR StatusLogger Unrecognized format specifier [level] ERROR StatusLogger Unrecognized conversion specifier [level] starting at position 35 in conversion pattern. ERROR StatusLogger Unrecognized format specifier [logger] ERROR StatusLogger Unrecognized conversion specifier [logger] starting at position 47 in conversion pattern. ERROR StatusLogger Unrecognized format specifier [msg] ERROR StatusLogger Unrecognized conversion specifier [msg] starting at position 54 in conversion pattern. ERROR StatusLogger Unrecognized format specifier [n] ERROR StatusLogger Unrecognized conversion specifier [n] starting at position 56 in conversion pattern. ERROR StatusLogger Unrecognized format specifier [d] ERROR StatusLogger Unrecognized conversion specifier [d] starting at position 16 in conversion pattern. ERROR StatusLogger Unrecognized format specifier [thread] ERROR StatusLogger Unrecognized conversion specifier [thread] starting at position 25 in conversion pattern. ERROR StatusLogger Unrecognized format specifier [level] ERROR StatusLogger Unrecognized conversion specifier [level] starting at position 35 in conversion pattern. ERROR StatusLogger Unrecognized format specifier [logger] ERROR StatusLogger Unrecognized conversion specifier [logger] starting at position 47 in conversion pattern. ERROR StatusLogger Unrecognized format specifier [msg] ERROR StatusLogger Unrecognized conversion specifier [msg] starting at position 54 in conversion pattern. ERROR StatusLogger Unrecognized format specifier [n] ERROR StatusLogger Unrecognized conversion specifier [n] starting at position 56 in conversion pattern. 

pom.xml config . log4j2.version = 2.10.0, spring boot version is 1.5.9.RELEASE

<dependencies>     <dependency>         <groupId>org.springframework.boot</groupId>         <artifactId>spring-boot-starter</artifactId>         <exclusions>             <exclusion>                 <groupId>org.springframework.boot</groupId>                 <artifactId>spring-boot-starter-logging</artifactId>             </exclusion>         </exclusions>     </dependency>     <dependency>         <groupId>org.slf4j</groupId>         <artifactId>slf4j-api</artifactId>         <version>1.7.25</version>     </dependency>     <dependency>         <groupId>org.apache.logging.log4j</groupId>         <artifactId>log4j-slf4j-impl</artifactId>         <version>${log4j2.version}</version>     </dependency>     <dependency>         <groupId>org.apache.logging.log4j</groupId>         <artifactId>log4j-api</artifactId>         <version>${log4j2.version}</version>     </dependency>     <dependency>         <groupId>org.apache.logging.log4j</groupId>         <artifactId>log4j-core</artifactId>         <version>${log4j2.version}</version>     </dependency> </dependencies> <build>     <plugins>         <plugin>             <groupId>org.apache.maven.plugins</groupId>             <artifactId>maven-shade-plugin</artifactId>             <version>3.1.0</version>             <configuration>                 <createDependencyReducedPom>false</createDependencyReducedPom>             </configuration>             <executions>                 <execution>                     <phase>package</phase>                     <goals>                         <goal>shade</goal>                     </goals>                     <configuration>                         <transformers>                             <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">                                 <resource>META-INF/spring.handlers</resource>                             </transformer>                             <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">                                 <resource>META-INF/spring.schemas</resource>                             </transformer>                         </transformers>                         <filters>                             <filter>                                 <artifact>*:*</artifact>                                 <excludes>                                     <exclude>META-INF/*.SF</exclude>                                     <exclude>META-INF/*.DSA</exclude>                                     <exclude>META-INF/*.RSA</exclude>                                 </excludes>                             </filter>                         </filters>                     </configuration>                 </execution>             </executions>         </plugin>         <plugin>             <artifactId>maven-compiler-plugin</artifactId>             <configuration>                 <source>1.8</source>                 <target>1.8</target>             </configuration>         </plugin>     </plugins>     <resources>         <resource>             <directory>src/main/resources</directory>         </resource>     </resources>     <sourceDirectory>src/main/java</sourceDirectory> </build> 

log4j2.xml config

<?xml version="1.0" encoding="UTF-8"?> <Configuration status="debug" monitorInterval="30" shutdownHook="disable">     <properties>         <property name="LOG_HOME">/data1/logs</property>         <property name="JOB_NAME">noname</property>     </properties>     <Appenders>         <Console name="Console" target="SYSTEM_OUT">             <PatternLayout pattern="%date{yyyy-MM-dd HH:mm:ss} [%t] %level [%logger{36}][%file:%line] %msg%n%throwable"/>         </Console>          <RollingRandomAccessFile name="DetailFile"                                  fileName="${sys:LOG_HOME}/${sys:JOB_NAME}/detail.log" bufferedIO="false"                                  filePattern="${sys:LOG_HOME}/${sys:JOB_NAME}/detail.%d{yyyy-MM-dd}-%i.log">              <PatternLayout                     pattern="%date{yyyy-MM-dd HH:mm:ss} [%t] %level [%file:%line] %msg%n%throwable"/>             <Policies>                 <TimeBasedTriggeringPolicy interval="1" modulate="true"/>                 <SizeBasedTriggeringPolicy size="500 MB"/>             </Policies>         </RollingRandomAccessFile>         <RollingRandomAccessFile name="error"                                  fileName="${sys:LOG_HOME}/${sys:JOB_NAME}/error.log" bufferedIO="true"                                  filePattern="${sys:LOG_HOME}/${sys:JOB_NAME}/error.%d{yyyy-MM-dd}.log">              <PatternLayout                     pattern="%date{yyyy-MM-dd HH:mm:ss} [%t] %level [%logger{36}:%line] %msg%n%throwable"/>             <Policies>                 <TimeBasedTriggeringPolicy interval="1" modulate="true"/>             </Policies>         </RollingRandomAccessFile>     </Appenders>     <Loggers>         <Root level="info">             <AppenderRef ref="DetailFile"/>             <AppenderRef level="error" ref="error"/>         </Root>     </Loggers> </Configuration> 

Answer 1

If a dependency contains log4j2 plugin, a Log4j2Plugins.dat cache file is included in the jar. When the Maven shade plugin is used to merge multiple jars with a Log4j2Plugins.dat file, only one will survive. Without the plugin definitions, errors are shown on startup. Log4j2 issue

One solution for this is excluding Log4j2Plugins.dat cache file from shaded jar so that Log4j scans for plugins on startup. For this, add a filter in maven-shade-plugin configuration in your pom:

    <plugin>         <groupId>org.apache.maven.plugins</groupId>         <artifactId>maven-shade-plugin</artifactId>         <version>3.1.0</version>         <configuration>             <createDependencyReducedPom>false</createDependencyReducedPom>             <filters>                 <filter>                     <artifact>*:*</artifact>                     <excludes>                         <exclude>**/Log4j2Plugins.dat</exclude>                     </excludes>                 </filter>             </filters>         </configuration>         ...     </plugin> 

Another solution is to merge the cache files using a transformation plugin which is log4j version specific.