Java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory 解决方案

Spring3.1启动时报错： 
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory 
at org.springframework.core.CollectionFactory.<clinit>(CollectionFactory.java:64) 
at org.springframework.core.SimpleAliasRegistry.<init>(SimpleAliasRegistry.java:41) 
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.<init>(DefaultSingletonBeanRegistry.java:73) 
at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.<init>(FactoryBeanRegistrySupport.java:41) 
at org.springframework.beans.factory.support.AbstractBeanFactory.<init>(AbstractBeanFactory.java:146) 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.<init>(AbstractAutowireCapableBeanFactory.java:144) 
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.<init>(AbstractAutowireCapableBeanFactory.java:155) 
at org.springframework.beans.factory.support.DefaultListableBeanFactory.<init>(DefaultListableBeanFactory.java:121) 
at org.springframework.beans.factory.xml.XmlBeanFactory.<init>(XmlBeanFactory.java:72) 
at org.springframework.beans.factory.xml.XmlBeanFactory.<init>(XmlBeanFactory.java:61) 
at spring.test.SpringTest.main(SpringTest.java:12) 
Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory 
at java.net.URLClassLoader$1.run(Unknown Source) 
at java.security.AccessController.doPrivileged(Native Method) 
at java.net.URLClassLoader.findClass(Unknown Source) 
at java.lang.ClassLoader.loadClass(Unknown Source) 
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) 
at java.lang.ClassLoader.loadClass(Unknown Source) 

解决方案：缺少 commons-logging.jar，也可以添加commons-logging-1.0.4.jar，建议使用后者或者更新版本。