On debian4, install java5: sudo aptitude install sun-java5-jdk with Aptitude
The version information running in java-version is similar to: --------------------------------------- java version "1.5.0 _ 17" Java (TM) 2 Runtime Environment, Standard Edition (build 1.5.0 _ 17-b04) Java HotSpot (TM) client VM (build 1.5.0 _ 17-b04, mixed mode, sharing) ------------------------------------------ the last sharing is very strange. If this information is not found in the installed version, aptitude install tomcat 5.5 installed, it may conflict with log4j. The error is similar :----------------------------- -------------------------------------------- Org. apache. commons. logging. logConfigurationException: org. apache. commons. logging. logConfigurationException: No suitable Log constructor [Ljava. lang. class; @ 8b058b for org. apache. commons. logging. impl. log4JLogger (Caused by java. lang. noClassDefFoundError: org/apache/log4j/Category) (Caused by org. apache. commons. logging. logConfigurationException: No suitable Log constructor [Ljava. lang. class; @ 8b058b for org. apache. commons. logging. impl. log4JLogger (Caused by java. lang. noClassDefFoundError: org/apache/log4j/Category) at org. apache. commons. logging. impl. logFactoryImpl. newInstance (LogFactoryImpl. java: 543) at org. apache. commons. logging. impl. logFactoryImpl. getInstance (LogFactoryImpl. java: 235) at org. apache. commons. logging. logFactory. getLog (LogFactory. java: 370) at org. apache. catalina. core. containerBase. getLogger (ContainerBase. java: 381) at org. apache. catalina. core. standardContext. start (StandardContext. java: 4119) at org. apache. catalina. core. containerBase. addChildInternal (ContainerBase. java: 760) at org. apache. catalina. core. containerBase. addChild (ContainerBase. java: 740) at org. apache. catalina. core. standardHost. addChild (StandardHost. java: 544) at org. apac He. catalina. startup. hostConfig. deployWAR (HostConfig. java: 831) at org. apache. catalina. startup. hostConfig. deployWARs (HostConfig. java: 720) at org. apache. catalina. startup. hostConfig. deployApps (HostConfig. java: 490) at org. apache. catalina. startup. hostConfig. start (HostConfig. java: 1149) at org. apache. catalina. startup. hostConfig. lifecycleEvent (HostConfig. java: 311) at org. apache. catalina. util. lifecycleSuppo Rt. fireLifecycleEvent (LifecycleSupport. java: 120) at org. apache. catalina. core. containerBase. start (ContainerBase. java: 1022) at org. apache. catalina. core. standardHost. start (StandardHost. java: 736) at org. apache. catalina. core. containerBase. start (ContainerBase. java: 1014) at org. apache. catalina. core. standardEngine. start (StandardEngine. java: 443) at org. apache. catalina. core. standardService. start (StandardSer Vice. java: 448) at org. apache. catalina. core. standardServer. start (StandardServer. java: 700) at org. apache. catalina. startup. catalina. start (Catalina. java: 552) at sun. reflect. nativeMethodAccessorImpl. invoke0 (Native Method) at sun. reflect. nativeMethodAccessorImpl. invoke (NativeMethodAccessorImpl. java: 39) at sun. reflect. delegatingMethodAccessorImpl. invoke (DelegatingMethodAccessorImpl. java: 25) at java. lang. Reflect. method. invoke (Method. java: 585) at org. apache. catalina. startup. bootstrap. start (Bootstrap. java: 295) at org. apache. catalina. startup. bootstrap. main (Bootstrap. java: 433) Caused by: org. apache. commons. logging. logConfigurationException: No suitable Log constructor [Ljava. lang. class; @ 8b058b for org. apache. commons. logging. impl. log4JLogger (Caused by java. lang. noClassDefFoundError: org/apache/log4j/Ca Tegory) at org. apache. commons. logging. impl. logFactoryImpl. getLogConstructor (LogFactoryImpl. java: 413) at org. apache. commons. logging. impl. logFactoryImpl. newInstance (LogFactoryImpl. java: 529 )... 26 moreCaused by: java. lang. noClassDefFoundError: org/apache/log4j/Category at java. lang. class. getDeclaredConstructors0 (Native Method) at java. lang. class. privateGetDeclaredConstructors (Class. java: 2357) at jav A. lang. class. getConstructor0 (Class. java: 2671) at java. lang. class. getConstructor (Class. java: 1629) at org. apache. commons. logging. impl. logFactoryImpl. getLogConstructor (LogFactoryImpl. java: 410 )... 27 more then check the information of the commons-logging-api-1.1.1.jar file under/usr/share/java, ls-l out if the size is 38015, replace with a size of 47724 Or a larger file. I searched the internet, and only.