我在类路径中有commons-logging.jar(v1.0.4)和log4j-1.2.8.jar,并获得以下运行时错误：
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)
解决方法
如果使用Maven,则必须确保在pom.xml中声明commons-logging和log4j
<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>
如果您声明只有commons-logging您获得错误Log4JLogger找不到或不可用
