FAQ #39 - Handling session expiration redirection in ADF 12c

Introduction

So how is this handled in 12c? I asked this to myself when I had to migrate an 11g ADF application to 12c. It seems that other people are asking about it too (see: https://community.oracle.com/thread/3952768, https://community.oracle.com/message/12531687#12531687, https://community.oracle.com/message/12497105#12497105 and so on) but no answers yet. The tried and tested implementation in 11g was to implement a custom filter, detect a session expiration and if that occurs redirect to a session-expired page. This is all good but... it does not work in 12c.

Main Theme

Google this

It is unfortunate for yet another instance there is practically no documentation on this at all. After googling intensly on the topic for a couple of days (talk about "agile" programming), I landed on this Oracle A-TEAM blog post, which seemed promising: http://www.ateam-oracle.com/customizing-session-time-out-pop-ups/. The post details how to customize the session expiration dialogs. Right at the top of the post there is a link with tips-on-dealing-with-the-session-time-out-popup. Eureka! As an older Greek colleague once said. So I navigated to it (http://www.ateam-oracle.com/tips-on-dealing-with-the-session-time-out-popup/) only to find out - to my dissapointment - that this was the good old 11g approach. Bammer.

Deep poetry

Well, not everything was lost. A small glimpse of hope appeared thanks to an initially seeming esoteric comment at the bottom by Deep Saurabh (Thank you Mr. Saurabh). And the comment goes something like this:

"If neither of above two is working , override NewSessionURLProvider service/provider.
( http://docs.oracle.com/middleware/1212/adf/FACAR/oracle/adf/view/rich/context/NewSessionURLProvider.html )
In the web lib’s META-INF/services folder you should have file:
oracle.adf.view.rich.context.NewSessionURLProvider
(for quick test run from jdev create META-INF/services under your ViewController/public_html/WEB-INF/classes/)

Which should contain FQCN of your custom overridden AdfcNewSessionURLProvider class."

Hmm? What did the Deep poet mean?

Enter NewSessionURLProvider

Well, other than the Deep comment above - which at the time I did not quite understand - the only other thing I had to go was the NewSessionURLProvider class. Here is the 12.2.1 class JavaDoc: https://docs.oracle.com/middleware/1221/adf/api-reference-faces/oracle/adf/view/rich/context/NewSessionURLProvider.html
The class is simple enough. It is an abstract class that needs to be overridden in the 12c ADF application by implementing the getNewSessionURL() method. As the documentation states, getNewSessionURL() is "Used to provide the view with a URL to create a new session if the current session expires while the current page is displayed.". Like I said, simple enough. That would be the first step. Override NewSessionURLProvider in your ADF application and provide an implementation for getNewSessionURL(). The code should look like this:

package com.jdeveloper.faq.services;

public class MyNewSessionURLProvider extends NewSessionURLProvider {
  @override
  public String getNewSessionURL(FacesContext fc) {
    return "pages/YourSessionExpirationPage.html";
  }
}

All you have to do is return the page that you want the application to redirect upon session expiration.

What next?

It is unclear what needs to happen next, to miraculously connect your ADF 12c application to the ADF framework and instruct it to redirect to your page. If you decypher the line "In the web lib’s META-INF/services folder you should have file: oracle.adf.view.rich.context.NewSessionURLProvider" from the comment above, it simply states what needs to be done next:

In your application's JDeveloper web ViewController project, under the src/META-INF directory create a new directory called services.In the src/META-INF/services directory create a text file (no extension) literally called oracle.adf.view.rich.context.NewSessionURLProvider. Edit the src/META-INF/services/oracle.adf.view.rich.context.NewSessionURLProvider text file and in it type the FQCN of your overridden NewSessionURLProvider class. This is what the src/META-INF/services/oracle.adf.view.rich.context.NewSessionURLProvider text file should look like:

com.jdeveloper.faq.services.MyNewSessionURLProvider

That's all?

Pretty much. The only other thing that needs to be done is to ensure that the src/META-INF/services/oracle.adf.view.rich.context.NewSessionURLProvider file in included in your deployed WAR file (during the application EAR deployment). In order to do that, edit the web ViewController deployment profile properties and under the WEB-INF/classes file group Contributors ensure that the Project Source Path is checked. Verify that the services/oracle.adf.view.rich.context.NewSessionURLProvider is included in the file list by selecting Filters under the WEB-INF/classes file group. Once you deploy your application, open the WAR and ensure that the services/oracle.adf.view.rich.context.NewSessionURLProvider text file is indeed included in the archive.

You are now ready to test it. Don't forget to remove the 11g custom filter implementation from web.xml.

Conclusion

I personally like the session expiration redirection implementation in 12c. No need to come with custom filters and all. Hopefully this will be documented in future releases of ADF.

Until the next post,(and that may be a long long time...) have fun with JDeveloping!