Which option to choose for accessing Web Services in ADF
By Frank Nimphius-Oracle on Apr 20, 2012
· Web Service Data Control
· JAX-WS proxy client and POJO Data Control
· JAX-WS proxy client and programmatic View Objects
Note: In the above, I exclude REST services in my recommendation because this is what ADF will address much better using the URL data control in JDeveloper 11g R2 (available) and with improved functionality in the upcoming Oracle JDeveloper 12c release.
For deciding which option to use for integrating Web Service, here is what I consider "a good rule of thumb"
1. Use Web Service Data Control only for simple service like weather reports or stock quotes
2. Use JAX-WS proxy client for all more complex services and access them from
a. Programmatic view object and entity if your business service is ADF Business Components as this allows for better integration with database queried views
i. Use View Objects only for read only access
ii. Use View Objects and Entities for CRUD Web Service integration
b. POJO Data Control
i. If your business service is not ADF BC.
ii. If the WS doesn't require integration in ADF business component
iii. If WS access should be from a bounded task flow in an ADF library for maximum reuse
As a general hint of best practice: Never use the JAX-WS generated proxy client directly. Always access it from a wrapper bean to avoid code losses or problem in cases where the proxy client needs to be re-generated.
Note: ADF Code Corner published an article explaining how to cache Web Services results when using JAX-WS proxy clients to avoid unnecessary round trips. See: http://www.oracle.com/technetwork/developer-tools/adf/learnmore/92-cache-ws-queries-523136.pdf