Name: krC82822 Date: 03/11/2001


java version "1.3.0_01"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0_01)
Java HotSpot(TM) Client VM (build 1.3.0_01, interpreted mode)

There are two related problems here.

1) There is a difference in behavior between ORB.create_value_tc and
ORBSingleton.create_value_tc, with respect to the concrete_base argument.
The latter tests for a null value and substitutes a tk_null TypeCode,
whereas the former does not. If you use ORB.create_value_tc and
pass a null value for concrete_base, a NullPointerException will
occur. To be compliant, the create_value_tc operation must accept
a null value for the concrete base type. Section 10.7.3 of CORBA 2.3
(OMG document 98-12-01) states:

"For create_value_tc operation, the concrete_base parameter is a TypeCode for
the immediate concrete valuetype base of the valuetype for which the TypeCode is
being created. If the valuetype does not have a concrete base, the concrete_base
parameter is a nil TypeCode reference."

2) Assuming that you managed to successfully create a valuetype with no
concrete base type, calling TypeCode.concrete_base_type() returns the
tk_null TypeCode. This is not compliant. Section 10.7.1 of CORBA 2.3
(OMG document 98-12-01) states:

"If the valuetype represented by the target TypeCode has a concrete base
valuetype, the concrete_base_type operation returns a TypeCode for the
concrete base, otherwise it returns a nil TypeCode reference."

  To summarize, create_value_tc must accept a null value for the concrete
base argument, and concrete_base_type must return a null value when
appropriate.

These problems can be reproduced using this example:

public class TypeCodeBugs
{
    private static void
    usage()
    {
        System.out.println("Usage: TypeCodeBugs (full|singleton)");
        System.exit(0);
    }

    public static void
    main(String[] args)
    {
        try
        {
            if(args.length == 0)
                usage();

            org.omg.CORBA.ORB orb = null;
            if(args[0].equals("full"))
                orb = org.omg.CORBA.ORB.init(args, null);
            else if(args[0].equals("singleton"))
                orb = org.omg.CORBA.ORB.init();
            else
                usage();

            org.omg.CORBA.TypeCode tc =
                orb.create_value_tc("IDL:Foo:1.0", "Foo",
                                    org.omg.CORBA.VM_NONE.value,
                                    null, new org.omg.CORBA.ValueMember[0]);

            org.omg.CORBA.TypeCode concreteBaseType = tc.concrete_base_type();
            if(concreteBaseType == null)
                System.out.println("This is the correct result");
            else if(concreteBaseType.kind() == org.omg.CORBA.TCKind.tk_null)
                System.out.println("This is the incorrect result");
        }
        catch(org.omg.CORBA.TypeCodePackage.BadKind ex)
        {
            ex.printStackTrace();
        }
    }
}
(Review ID: 118544)
======================================================================

Name: krC82822 Date: 03/20/2001


The problem happens with both Java 1.2.2 and Java 1.3.0 on both NT and Solaris.

JDK ORB.create_value_tc() throws a NullPointerException when the concrete base
parameter is passed a null. The problem happens with both applets and
applications. It is platform & JDK version independent (it happens on both NT
and Solaris, with both JDK1.2.2 and JDK1.3.0).

Here is a simple test case:

======== ResultObject.java =============

import java.util.*;
import java.io.*;
import java.text.*;

public class ResultObject implements Serializable
{
     public ResultObject()
     {
     }
}

========= Tester.java ======================

public class Tester extends java.applet.Applet{
  public void init() {
    try {
      System.out.println("Initializing ORB in main");
      org.omg.CORBA.ORB orb = org.omg.CORBA.ORB.init(this,null);
      org.omg.CORBA.TypeCode tc =
orb.create_value_tc("RMI:ResultObject:71DA8BE7F971128","ResultObject",(short)0,n
ull, new org.omg.CORBA.ValueMember[0]);
    } catch(Exception e) {
      e.printStackTrace();
    }
  }

  public static void main(String [] args) {
    try {
      System.out.println("Initializing ORB in main");
      org.omg.CORBA.ORB orb = org.omg.CORBA.ORB.init(args,null);
      org.omg.CORBA.TypeCode tc =
orb.create_value_tc("RMI:ResultObject:71DA8BE7F971128","ResultObject",(short)0,n
ull, new org.omg.CORBA.ValueMember[0]);
    } catch(Exception e) {
      e.printStackTrace();
    }
  }
}

=================== tester.html =======================

Test Applet
<br>
open java console to see results

<applet archive="" code="Tester.class" width="400" height="30">

</applet>


Steps to reproduce:
1. compile the above two java files:
     javac ResultObject.java Tester.java
2. run the application:
     java Tester
   and got the following exception stack trace:
   
   Initializing ORB in main
   java.lang.NullPointerException
at com.sun.CORBA.idl.TypeCodeImpl.<init>(TypeCodeImpl.java:492)
at com.sun.CORBA.idl.TypeCodeImpl.convertToNative(TypeCodeImpl.java:873)
at com.sun.CORBA.idl.TypeCodeImpl.<init>(TypeCodeImpl.java:688)
at com.sun.CORBA.idl.ORB.create_value_tc(ORB.java:1082)
at Tester.main(Tester.java:17)

3. run the applets with jdk1.2.2 or jdk1.3.0 appletviewer:
      appletviewer http://&lt;host&gt;:&lt;port&gt;/tester.html
   and got the following output:

   Initializing ORB in main
   java.lang.NullPointerException
at
com.sun.corba.se.internal.corba.TypeCodeImpl.<init>(TypeCodeImpl.java:495)
at
com.sun.corba.se.internal.corba.TypeCodeImpl.convertToNative(TypeCodeImpl.java:8
85)
at
com.sun.corba.se.internal.corba.TypeCodeImpl.<init>(TypeCodeImpl.java:690)
at com.sun.corba.se.internal.corba.ORB.create_value_tc(ORB.java:1303)
at Tester.init(Tester.java:7)
        at sun.applet.AppletPanel.run(AppletPanel.java:344)
        at java.lang.Thread.run(Thread.java:484)
(Review ID: 119133)
======================================================================