Passing data from Oracle stored procedures to Java

Question

We're going to write a new web interface for a big system based on Oracle database. All business rules are already coded in PL/SQL stored procedures and we'd like to reuse as much code as possible. We'll write some new stored procedures that will combine the existing business rules and return the final result dataset.
We want to do this on the database level to avoid java-db round trips. The interface layer will be written in Java (we'd like to use GWT), so we need a way of passing data from Oracle stored procedures to Java service side. The data can be e.g. a set of properties of a specific item or a list of items fulfilling certain criteria. Would anyone recommend a preferable way of doing this?
We're considering one of the 2 following scenarios:
passing objects and lists of objects (DB object types defined on the schema level)
passing a sys_refcursor
We verified that both approaches are "doable", the question is more about design decision, best practice, possible maintenance problems, flexibility, etc.
I'd appreciate any hints.

Answer 1

user1754151 wrote:
We're going to write a new web interface for a big system based on Oracle database. All business rules are already coded in PL/SQL stored procedures and we'd like to reuse as much code as possible. We'll write some new stored procedures that will combine the existing business rules and return the final result dataset.
We want to do this on the database level to avoid java-db round trips. The interface layer will be written in Java (we'd like to use GWT), so we need a way of passing data from Oracle stored procedures to Java service side. The data can be e.g. a set of properties of a specific item or a list of items fulfilling certain criteria. Would anyone recommend a preferable way of doing this?
We're considering one of the 2 following scenarios:
passing objects and lists of objects (DB object types defined on the schema level)
passing a sys_refcursor
We verified that both approaches are "doable", the question is more about design decision, best practice, possible maintenance problems, flexibility, etc.
I'd appreciate any hints.If logic is already written in DB, and the only concern is of passing the result to java service side, and also from point of maintenance problem and flexibility i would suggest to use the sys_refcursor.
The reason if Down the line any thing changes then you only need to change the arguments of sys_refcursor in DB and as well as java side, and it is much easier and less efforts compare to using and changes required for Types and Objects on DB and java side.
The design and best practise keeps changing based on our requirement and exisiting design. But by looking at your current senario and design, i personally suggest to go with sys_refcursor.