Problem:

Before the delivery of Net Express 5.1 Websync2, it was not possible for an OO COBOL program to consume a Java class's constructor that throws an exception. This has been fixed in Net Express 5.1 Websync2.

The COBOL Code which creates an instance of JAVA class SimpleClass appears below. It is also attached to this article.

ExceptionCatcher.cbl
      $set ooctrl ( p-f)
       program-id. ExceptionCatcher.


       class-control.
           SimpleClass is class "$JAVA$SimpleClass"
           EntryCallback is class "entrycll"
           JavaExceptionManager is class "javaexpt"
           ExceptionManager is class "exptnmgr"


           javasup    is class "javasup"
           .
       working-storage section.
& 


       procedure division.
      *>---Set up Exception handler
           invoke EntryCallback "new" using z"JException"
                                  returning wsCallback
           invoke ExceptionManager "register"
                                        using javaexceptionmanager
                                              wsCallback
      *>---Instantiate the class
           invoke SimpleClass "new" returning theInstance
           display "instantiated"
& 


           display "COBOL: Exception excepted in constructor"
           stop run.


       entry "Jexception" using lnkException.


            display "Jexception: Exception occured"
            invoke lnkException "display"
            invoke javasup "exceptionOccurred"
                   returning theJavaException
            IF     theJavaException not = null
               display "Jexception: retrieve exception's content"
               invoke theJavaException      "printStackTrace"
               invoke theJavaException      "toString"
                       returning aStr
               call "strlen" using aStr returning aStrlength
               display "Jexception:  exception's content: "
                                         aStr(1:aStrlength)
            else
               display "!!!! theJavaException  = null !!!"
            END-IF


            invoke javasup "exceptionClear"
            set address of lnkException        to null
            set            theJavaException    to null
            exit program.
            .


           . & 


SimpleClass.java :
import java.lang.* ;
public class SimpleClass {
  public SimpleClass() {
  }


  public SimpleClass(int i ) throws Exception{
     String s = "\\nJAVA: Test error in Class's constructor\\n";
	 System.out.println(s);
     Exception e = new Exception (s);
     throw e;
  }


  public void TestException() throws Exception
  {
     Exception e = new Exception ("Test error" );
     throw e;
  }
}

Resolution:

Install Net Express Websync2 update.