I have created an ADF application in JDeveloper 12.1.3 in which I created restful web services in the app module for the business components. I created another ViewObject by custom sql query and added to app module and created rest services for it. Suddenly all my existing rest services are disappeared from the app module window and + button under REST tab is also disabled as shown in the below image. There is no error or alert shown.
I can see the xml files in the project structure but are not appeared in the AppModule window.
While creating my new view object by sql , I have not given any key attribute and added it to app module. I rolled back my changes and created the same view object with a key attribute and created rest service for the same view object now and it worked. It added to the list of rest services in the app module and all are appeared.
When you create rest service to any VO, an xml file like below is created.
When you delete the REST service, this file will not be deleted. If you try to create REST service again with the same name, then also you face the above issue. So, check if this xml file is deleted from the project before creating new one.