PH41892: Fix ECJ ClassCastException in JSP

APAR status

• Closed as program error.

Error description

• A Open Liberty regression has been found in the jsp features
  after upgrading the ECJ (Eclipse Compiler for Java) in
  21.0.0.9.
  
  The following error can occur when inner classes are used
  within a JSP page:
  Error 500: java.lang.ClassCastException: class
  org.eclipse.jdt.internal.compiler.lookup.PlainPackageBinding
  cannot be cast to class
  org.eclipse.jdt.internal.compiler.lookup.TypeBinding
  
  The fix is targeted for 21.0.0.12.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  Liberty users of JavaServer Pages (JSP) on  *
  *                  21.0.0.9, 21.0.0.10, or 21.0.0.11           *
  ****************************************************************
  * PROBLEM DESCRIPTION: Customers may encounter the following   *
  *                      java.lang.ClassCastException exception  *
  *                      on their JSP page:                      *
  *                      java.lang.ClassCastException: class     *
  *                      org.eclipse.jdt.internal.compiler.looku *
  *                      p.PlainPackageBinding cannot be cast to *
  *                      class                                   *
  *                      org.eclipse.jdt.internal.compiler.looku *
  *                      p.TypeBinding                           *
  *                      (org.eclipse.jdt.internal.compiler.look *
  *                      up.PlainPackageBinding and              *
  *                      org.eclipse.jdt.internal.compiler.looku *
  *                      p.TypeBinding are in unnamed module of  *
  *                      loader                                  *
  *                      org.eclipse.osgi.internal.loader.Equino *
  *                      xClassLoader @3522bc53)  This exception *
  *                      will occur if the JSP page defines and  *
  *                      uses an inner class.                    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  This problem was introduced after an update to the Eclipse Java
  Compiler dependency (part of JDT) in the JSP features.  The
  compiler code within the JSP implementation did not properly
  differentiate an inner class from a package.
  

Problem conclusion

• The code has been updated to avoid this ClassCastException. The
  Open Liberty issue can be found here:
  https://github.com/OpenLiberty/open-liberty/issues/19197.
  
  The fix for this APAR is targeted for version 21.0.0.12.
  
  Please refer to the recommended updates page for delivery
  information:
  
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  WAS LIBERTY COR

• Fixed component ID

  5725L2900

Applicable component levels