EASC

EASC and enums

Quite a while ago, we showed a workaround on how to work with enum types and the Remote API. A bit later, there was RFC #0132 which added real enum types to the XP Framework, but support for them in EASC was forgotten. This oversight has now been resolved.

RFC #0132: Enum support

Scope of Change
There will be a defined way to write enums.

Rationale
Interaction with programming languages with enums, via EASC, for example.

Read the full RFC here

EASC and enum types

While developing a client for a stateless session bean deployed on an enabled application server for a corporate project, I stumbled upon the need to pass a Java 5 enum. It was part of the signature of a remote method which was something along the lines of:
public CaseId createCase(FaxId faxId, Provider provider, String url);

The Provider is an enumeration type, declared as follows:
public enum Provider { FAXTOOL, ORDERING, TELECOM }

Because PHP does not support enums, we will have to find a workaround.

EASC.NET

Following the Perl EASC implementation, I started developing a .NET implementation of the EASC protocol using the C# programming language. Its sourcecode is available at http://experiments.xp-framework.net/?arena,easc-csharp .

Update (2007-04-01): Fixed the last couple of outstanding issues and now have the first working implementation:

.NET EASC client in a Cygwin Shell, remotely invoking a unittest in Peking

Perl EASC implementation

Besides XP4 and XP5, we're trying to get more languages to implement the EASC protocol. Yesterday, I committed a Perl implementation originally written by Marc to the XP SVN repository, testing and fixing bugs while doing so.

The experiment is available here:
http://experiments.xp-framework.net/?arena,easc-perl

RFC #0110: RemoteStackTraceElement

Scope of Change
Stack trace elements representing stack frames on the remote side will be mapped to RemoteStackTraceElement objects instead of StackTraceElements.

Rationale

• Ability to distinguish between local stack frames and remote stack frames.
• Get rid of "php." prefix (e.g., in "php.java.lang.reflect.Method")

RFC #0076: Transfer exception causes

Scope of Change
An exception's cause will be transferred via EASC to the client.

Rationale
The remote.InvocationException's stacktrace is not really helpful in finding what may have caused a serverside exception.

Read the full RFC here

RFC #0062: HA-JNDI

Scope of Change
The ability to pass a list of servers to the Remote API will be added.

Rationale
Load balancing and failover.

Read the full RFC here

Support for readResolve()

The EASC's Java deserializer now supports correctly objects that have a readResolve() method. See Java Object Serialization Specification: 3.7 The readResolve Method for details.

EASC API moved

The EASC API was moved in SVN from experiments/arena/easc to ext/java/easc. EASC has been in productive use for a couple of weeks here at Schlund+Partner and has proven to work.

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