title: In weblogic.xml, <prefer-application-packages> is not working?
body: <p>I have tried a lot of solutions/ try and error which I got from stackover flow and through googling. Using Weblogic 12.2.1.3 and my project <strong>weblogic.xml</strong> </p>
  
  <pre><code>&lt;wls:weblogic-web-app
          xmlns:wls="http://xmlns.oracle.com/weblogic/weblogic-web-app"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://xmlns.oracle.com/weblogic/weblogic-web-app
  http://xmlns.oracle.com/weblogic/weblogic-web-app/1.8/weblogic-web-app.xsd"&gt;
  
        &lt;security-role-assignment&gt;
          &lt;role-name&gt;admin&lt;/role-name&gt;
          &lt;principal-name&gt;Administrators&lt;/principal-name&gt;
       &lt;/security-role-assignment&gt;
  
       &lt;wls:container-descriptor&gt;
        &lt;wls:prefer-application-packages&gt;
             &lt;wls:package-name&gt;org.opensaml&lt;/wls:package-name&gt;
        &lt;/wls:prefer-application-packages&gt;
  
        &lt;wls:show-archived-real-path-enabled&gt;true&lt;/wls:show-archived-real-path-enabled&gt;
  
      &lt;/wls:container-descriptor&gt;
  
  &lt;/wls:weblogic-web-app&gt;
  </code></pre>
  
  <p>The issue is, even I mentioned in weblogic.xml about <strong>opensaml</strong> that take from my project, then also Server is taking from Oracle weblogic. It is not taking from my project. I am using 2.6.6 version of opensaml jar for my project. I have tried with <code>&lt;wls:package-name&gt;org.opensaml.*&lt;/wls:package-name&gt;</code> but no success. </p>
  
  <p>The main reason to check weblogic.xml is that when I tried to open one specific url it is showing following error in the browser. But it works for <strong>Tomcat</strong> server when you open the same url. So my assumption is weblogic.xml --> prefer-application-packages tag is not working.</p>
  
  <pre><code>java.lang.IncompatibleClassChangeError: Implementing class
      at java.lang.ClassLoader.defineClass1(Native Method)
      at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
      at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
      at weblogic.utils.classloaders.GenericClassLoader.defineClassInternal(GenericClassLoader.java:1113)
      at weblogic.utils.classloaders.GenericClassLoader.defineClass(GenericClassLoader.java:1046)
      at weblogic.utils.classloaders.GenericClassLoader.findLocalClass(GenericClassLoader.java:1038)
      at weblogic.utils.classloaders.GenericClassLoader.findClass(GenericClassLoader.java:990)
      at weblogic.utils.classloaders.ChangeAwareClassLoader.findClass(ChangeAwareClassLoader.java:104)
      at weblogic.utils.classloaders.GenericClassLoader.doFindClass(GenericClassLoader.java:611)
      at weblogic.utils.classloaders.GenericClassLoader.loadClass(GenericClassLoader.java:543)
      at weblogic.utils.classloaders.GenericClassLoader.loadClass(GenericClassLoader.java:496)
      at weblogic.utils.classloaders.ChangeAwareClassLoader.loadClass(ChangeAwareClassLoader.java:72)
      at weblogic.utils.classloaders.ChangeAwareClassLoader.loadClass(ChangeAwareClassLoader.java:53)
      at org.springframework.security.saml.SAMLBootstrap.postProcessBeanFactory(SAMLBootstrap.java:42)
      at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:284)
      at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:179)
  </code></pre>