Tuesday, August 7, 2007

Java 101: Generate a unique identifier with java.util.UUID

A friend of mine was asking me how to generate a unique ID for his application... As you probably already know Java SE 5 has introduced the java.util.UUID class to easily generate Universally Unique Identifier (UUID). As usual Wikipedia is a great starting point to learn more about UUID.
Generating the unique ID is as simple as calling the method UUID.randomUUID() in the class. This will give a new instance of UUID that you can now manipulate; for example do a toString() to get the UUID string representation as describe in the specifications; for example 5462dc18-4653-42d1-b4e4-22fc970a6ce5


Thursday, August 2, 2007

OracleAS, OC4J and Java EE releases....

This morning I was helping a customer to debug some Web Services deployment issues, when I simply realized that the error was coming from the fact that he was trying to deploy a JAX-RPC service on a OracleAS 10gR2 server; where it is not supported/available. This give me the opportunity to clarify the different versions of the Oracle Application Server and their related Java Enterprise Edition release support.

Oracle AS Release J2EE/Java EE Release Comments/Extensions Certification Matrix Java EE 5.0
  • Currently available as technology preview
(Oracle AS 10gR3)
J2EE 1.4
  • Support of EJB 3/JPA
  • Web Services Annotations
  • MTOM support (
  • Integration of Spring 2.0 (
  • Integrationf of Oracle Coherence (
OTN Certicification Matrix
(Oracle AS 10gR2)
J2EE 1.3OTN Certicification Matrix
9.0.4.x J2EE 1.3OTN Certicification Matrix
9.0.3.x J2EE 1.3OTN Certicification Matrix