java - Log4j2 configuration not found when running standalone application built by shade plugin

Question

I have application which when I run from maven log4j2 it is working:

mvn exec:java -Dexec.args=...

but when I run jar as standalone application then it shows error:

java -jar

log:

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 No log4j2 configuration file found. Using default configuration: logging only errors to the console.
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.

I dont understand this error. It shows that log4j2 configuration file is not found but also complain about some format which is probably in configuration file

My configuration is:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="off">
    <Appenders>
        <Console name="console" target="SYSTEM_OUT">
            <PatternLayout pattern="%d [%t] %-5p - %-26.26c{1} - %m
" />
        </Console>
    </Appenders>
    <Loggers>
        <Root level="info">
            <AppenderRef ref="console" />
        </Root>

        <Logger name="my.package" level="DEBUG" /> 

    </Loggers>
</Configuration>

and it is located in root directory of jar file.

UPDATE

jar is created by maven shade plugin:

        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>

so it contains all necessary libraries (about 23 MB) and when I run this jar I just need to specify arguments

Answer 1

ok I found this issue about this problem.

In short, the problem arises when application classes are packaged in uber jar using maven shade plugin. While for log4j2 version 2.8.1 the fix is still pending, the suggested workaround is to update maven pom.xml with extra configuration settings for shade plugin as follow:

    <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">

        . . . . .

        <build>
            . . . . . 
            <plugins>
                . . . . . 
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-shade-plugin</artifactId>
                    <version>2.4.1</version>
                    <configuration>
                        <filters>
                            <filter>
                                <artifact>*:*</artifact>
                                <excludes>
                                    <exclude>META-INF/*.SF</exclude>
                                    <exclude>META-INF/*.DSA</exclude>
                                    <exclude>META-INF/*.RSA</exclude>
                                </excludes>
                            </filter>
                        </filters>
                        <transformers>
                            <transformer
                                    implementation="com.github.edwgiz.mavenShadePlugin.log4j2CacheTransformer.PluginsCacheFileTransformer"/>
                        </transformers>
                    </configuration>
                    <executions>
                        <execution>
                            <phase>package</phase>
                            <goals>
                                <goal>shade</goal>
                            </goals>
                        </execution>
                    </executions>
                    <dependencies>
                        <dependency>
                            <groupId>com.github.edwgiz</groupId>
                            <artifactId>maven-shade-plugin.log4j2-cachefile-transformer</artifactId>
                            <version>2.1</version>
                        </dependency>
                    </dependencies>
                </plugin>
                . . . . . 
            </plugins>
        . . . . . 
        </build>
        . . . . . 
        <pluginRepositories>
            <pluginRepository>
                <id>oss.sonatype.org</id>
                <name>OSS Sonatype Staging</name>
                <url>https://oss.sonatype.org/content/groups/staging</url>
            </pluginRepository>
        </pluginRepositories>      
        . . . . . 
    </project>