Whats the root cause of Log4JLogger' cannot be found or is not useable?

Question

I have commons-logging.jar (v1.0.4) and log4j-1.2.8.jar in the classpath and getting following run-time error:

Caused by: org.apache.commons.logging.LogConfigurationException: User-specified log class 'org.apache.commons.logging.impl.Log4JLogger' cannot be found or is not useable.
    at org.apache.commons.logging.impl.LogFactoryImpl.discoverLogImplementation(LogFactoryImpl.java:874)
    at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:604)
    at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:336)
    at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:310)
    at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:685)

Answer 1

If you using Maven, you must ensure declare commons-logging and log4j in pom.xml

<dependencies>
    <dependency>
        <groupId>commons-logging</groupId>
        <artifactId>commons-logging</artifactId>
        <version>1.1.3</version>
    </dependency>
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency>
</dependencies>

if you declare only commons-logging you with getting error Log4JLogger cannot be found or is not useable