Weblogic Class Conflicts and Resolutions

CAT is a Web-based class analysis tool that comes with weblogic aids you in analyzing classloading issues, such as detecting conflicts, debugging application classpaths and class conflicts, and proposes solutions to help you resolve them.

Recently I ran into an issue where one of the method on ArrayUtils found in commons-lang was not found at runtime. CAT helped me to identify and the resolution was to add the jar file to the classpath in setDomainEnv.cmd

ar;C:\Oracle\Middleware\user_projects\domains\base_domain\lib\slf4j-log4j12-1.5.6.jar;C:\Oracle\Middleware\user_projects\domains\base_domain\lib\log4j-1.2.16.jar;C:\Oracle\Middleware\user_projects\domains\base_domain\lib\validation-api-1.0.0.GA.jar;C:\Oracle\Middleware\user_projects\domains\base_domain\lib\hibernate-validator-4.2.0.Final.jar;C:\Oracle\Middleware\user_projects\domains\base_domain\lib\commons-lang-2.6.jar

An outline of the steps will include:

1. Start Weblogic Application Server
2. Go to URL: http://localhost:7001/wls-cat 
3. On the left select your application and then click "Generate Report"
4. Select appropriate Class Loader and then enter fully qualified class name and you can see which jar is loaded

Resolution can include sometimes adding the jar to the classpath or pre-classpath in setDomainEnv.cmd file

You can find more info from Weblogic Documentation at You can find more information at http://docs.oracle.com/cd/E21764_01/web.1111/e13706/classloading.htm#BABHJGJJ