35
votes

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>
4
you want to ask a question here. I see an error, but no question. - Ctznkane525
i want to know how to solve this error - CoderMeng
With Java 11, we've ran into similar problems due to the locale - see issues.apache.org/jira/browse/LOG4J2-2435 - mkobit

4 Answers

65
votes

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.

13
votes

If you are using Gradle and ShadowJar 4+:

shadowJar{
  transform(com.github.jengelman.gradle.plugins.shadow.transformers.Log4j2PluginsCacheFileTransformer)
}

Gradle Kotlin DSL:

shadowJar {
    transform(com.github.jengelman.gradle.plugins.shadow.transformers.Log4j2PluginsCacheFileTransformer::class.java)
}
8
votes

Unfortunately, I can't reply to Shashank Kapoor answer, as he correctly pointed out excluding the Log4j2Plugins.dat file solves the issue. This did the trick for me while using gradle:

shadowJar {
    exclude "**/Log4j2Plugins.dat"
}
5
votes

I’ve seen this error before when people had multiple versions of Log4j2 on the classpath.