This is intended for the Joint Initial submission to the IDL4 to Java Language Mapping RFP,
mars/18-08-01.
However, on filling in the OMG issue reporting form, I could not find a way to specify this; as a fallback, I reference the IDL to Java Mapping 1.3 (formal/08-01-11) to which the same issue also applies.

Many of the IDL to Java translators support an option to specify a Java package prefix for the generated code (e.g. Oracle idlj option -pkgPrefix; JacORB option -i2jpackage; rtiddsgen option -package).
This is not exactly equivalent to hard coding the prefix as modules in the IDL: When using the translator option, other language mappings do not see the prefix.

The package prefix provided to the IDL translator may produce a conflict with names in the IDL file.
Example:

// file: test.idl
module test {

   enum com_t { zero, one };

   struct org_t {
      short foo;
   };

   typedef string<16> net_t;

   struct structure {
      com_t com;   // "com" is in conflict when providing prefix option such as: com.acme
      org_t org;   // "org" is in conflict when providing prefix option such as: org.acme
      net_t net;   // "net" is in conflict when providing prefix option such as: net.acme
   };

};

Notice that the Java generated for this IDL does not compile but it does compile for other languages (C++, Ada, etc).

Section 4.2 (Names) contains:

In general IDL names and identifiers are mapped to Java names and identifiers with no change.
If a name collision could be generated in the mapped Java code, the name collision is resolved by
prepending an underscore (_) to the mapped name.

Section 7.1.1 of mars/18-08-01 contains similar text.

I suggest adding a further sentence:

This also applies to name collisions caused by a Java package prefix specified at the IDL to Java translator.

I have a number of questions/concerns about the description/usage of
ORB.init arguments/properties.

1. There are only two properties described in the Java mapping spec:
org.omg.CORBA.ORBClass and org.omg.CORBA.ORBSingletonClass. Setting these
via property are described, but not setting these via application string
array (ie., args in main). Yet the spec says these values can be obtained
via the args array. I believe most folks assume "-ORBClass xxx" is the
convention, since that's what the JDK's ORB uses, but it's not documented.

2. Ditto for applet parameters. It's assumed that they are of the form

<param name = "org.omg.CORBA.ORBClass" value = "xxx">

but it is not documented.

3. Can this convention be generalized to accommodate the argument naming
convention in the core spec? If we follow the convention that says
org.omg.CORBA.ORBClass becomes -ORBClass; then can we say that a parameter
-ORBXXX may also be specified by the property or applet parameter
org.omg.CORBA.ORBXXX?

4. The text around the ORB arguments is tightly coupled to only ORBClass
and ORBSingletonClass. It does not seem to expect other args/properties.
For example: "...when creating an ORB instance, the class names of the ORB
implementation are located using the following search order: ...". I
assume the following search order also applies to any args/props.

5. The spec doesn't allow for extensions.

"See Table 1-3 for a list of the property names and values that are
recognized by
ORB.init. Any property names not in this list shall be ignored by
ORB.init()."

Has the INS spec updated this table with -ORBInitRef and
-ORBDefaultInitRef, for example? And the interceptor spec assumes that
services are allowed to have their own arguments. And what about
proprietary extensions? Given the word "shall", any extensions are
non-CORBA-compliant.

6. Repeated arguments fall apart when presented as Properties. For
example, the INS spec allows for the following invocation:

java myapp -ORBInitRef XX=xx -ORBInitRef YY=yy -ORBInitRef ZZ=zz

Since Properties entries are <key, value> pairs, and only one pair for a
given key can exist, then if we tried entering the above as Properties we'd
only get on of them, not all. I'm not sure how to fix this. Dictate that
XX, YY, ZZ be the end of the ORBInitRef string rather than the start of a
new string, perhaps? So then, specifying these as system properties for
example, we'd have:

java myapp -Dorg.omg.CORBA.ORBInitRefXX xx -Dorg.omg.CORBA.ORBInitRefYY yy
-Dorg.omg.CORBA.ORBInitRefZZ zz

That causes ugly parsing problems. We'd have to search the whole list of
properties that contained a key that merely BEGAN with
"org.omg.CORBA.ORBInitRef". And this falls apart in applets; we can get a
list of all Properties, but we cannot get a list of all applet parameters.
Personally I think this is a failing in the applet class, but that's life
as we know it.

I'm sorry to raise this as one issue instead of six, but most of these
points are tightly coupled, so I didn't want to distance them from each
other. And I'd like them all to be answered together anyway.

The Java source code for org.omg.PortableServer.POAOperations in ptc/02-06-14 defines the method create_reference_with_id as throwing org.omg.PortableServer.POAPackage.WrongPolicy. However, the CORBA/IIOP 2.4 specification (formal/00-10-01) specifies this operation as NOT raising any exceptions (see section 11.3.8.19). Which is correct?

The specification does not provide mapping descriptions for Home and Event IDL definitions (already part of CORBA 3.0) or Component (new in CORBA 3.1).

http://www.omg.org/docs/formal/02-08-05.pdf section 1.21.3 IDLEntity inclides the Serializable interface, but if an IDLEntity has a union, it will result in Holder classes (i.e. FloatHolder) which do not implement the Serializable interface. This results in NotSerializable exceptions being created when trying to use such objects with java serialization. The quick fix would be to specify that "public interface Streamable" should extend java.io.Serializable, since the holder classes extend from that as well.

The resolution of issue #3668 should have removed the definition of FixedHolder. There is no need for a Holder for an anonymous Fixed type since none can be defined. Type specific Holders are necessary in order to define the correct read and write operations that use the write_fixed and read_fixed defined by the resolution of 3668.

Proposed resolution:
Remove the definition of FixedHolder from section 1.4.1.4 (page 1-11).

The Messaging Specification was adopted before Java Portability
layer was really in place. In order to make portability work
with the asynchronous stubs which will in future be generated,
some things may be added to the portability interface.

Each stub has a sendc_<op> and sendp_<op> operation which
will need to call on the portable stub layer.

A first glance at the requirements to make a portable
implementation suggest that a sendc_invoke and sendp_invoke
operation will probably need to be added to ObjectImpl and
Delegate.

I dont know if this is viewed as a "compatible" class change
for JDK, or whether we will need to put derived classes
in CORBA_3_0 package....

In order to meet the interoperability compliance requirements,
ORBs must include an IIOP implementation using TCP/IP plain text
sockets. J2EE implementations are required to support CSIv2 and
thus need additional control over the sockets an ORB creates.
It may be necessary

• to get the ORB to listen on additional sockets, of differing
  types
• to get the ORB to connect to alternative sockets, of different
  types, for a given IOR
• for information about these sockets to be included in object
  references exported by the ORB
• for socket data to be available to request interceptors, e.g
  SSL certificates

Portable IORInterceptors can be used to add this information as
tagged components in the profiles within an IOR.

A mechanism is required to modify the ORB's behaviour to allow
it to handle different socket types, listen on additional sockets,
connect to alternative sockets and make additional data available
to interceptors.

Since this is a J2EE requirement which needs speedy resolution,
it seems appropriate to resolve it by the addition of Java
specific APIs in the IDL to Java specification. For example,

• a pluggable ORB socket factory could be introduced which would
  be used whenever the ORB needed to create a serverSocket or an
  outbound socket for a given IOR or end point

• a means of registering such a socket factory would be required.
  Options for this include:-
  . adding an ORB method: this may cause problems in initialisation
  . adding a Java specific extension to the PI ORBInitInfo interface
  so that the registration would need to be called from the
  pre_init/post_init methods in an ORBInitializer: this ties the
  Socket Factory with PIs, but both are likely to be required
  for J2EE.

• a means of specifying ports on which an ORB/POA should listen
  would be useful but this may be infeasible as part of this issue
  due to the variety of ORB/POA implementations.

• the PI Client and ServerRequestInfo and IORInfo interfaces may
  need to be extended to support access to Connection related data

There are several reasons that Java ORB.init should support
ORBId (without compromising security). For example:

• Services built on Portable Interceptors work in relation to the ORB
  with which they are registered. There needs to be some means of
  identifying this ORB (besides its reference) so other services or
  facades (e.g., JNDI) can use the same ORB.

• A Server Activation Framework needs an ORB Id to identify a particular
  orb (which hosts a persistent POA) within a server. The triple:
  server id, orb id, poa name is conceptually embedded in the adapter
  id of a POA making it unique.

In ptc/02-01-01, the latest compendium of predefined code for the IDL to Java mapping, the enumerations values captured in org.omg.CORBA.SetOverrideType are SET_OVERRIDE and ADD. The correct values are SET_OVERRIDE and ADD_OVERRIDE.