Resolution:
After upgrading the Java Virtual Machine when using Weblogic (for example, from 1.4.1 to 1.4.2) , errors may occur similar to this: Compilation of 'd:\app\grid\server\config\mydomain\.\DIRECTOR\.wlnotdelete\extract\DIRECTOR_DIRECTOR_livecluster\jsp_servlet\_admin\_engine\__enginelogfiles.java' failed:

One way to fix this problem is to use jikes as the jsp compiler: weblogic deployment descriptor (weblogic.xml):

&ltweblogic-web-app>
  &ltjsp-descriptor>
    &ltjsp-param>
      &ltparam-name>
        compileCommand
      </param-name>
      &ltparam-value>
        C:dsservers3.2.2datasynapsebinjikes.exe
      </param-value>
    </jsp-param>
  </jsp-descriptor>
</weblogic-web-app>

Java errors after JVM upgrade with Weblogic