Abhishek Tanwar

I build web & mobile experiences

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How to implement offline struts actions?

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This is part 2 of my first post. This is my way to efficiently handle offline struts actions and notify the status as GET API requests. Entire code is available on my Gitlab (@tony2k84). I have included the link at the bottom of the post.

Let’s begin.

Folder Structure

First, my folder structure. I have divided into JSPs, listeners, API, pojo, struts classes and core framework. I will describe each one in summary below.

folder-structure
folder-structure

 

Request and Response JSP

To get the concept going, I have basic action input (form) and output redirection JSPs.

Request and Response JSPs
Request and Response JSPs

Nothing fancy here. Just a simple JSP submitting the form to a struts action and struts action REDIRECTING (not just forwarding) the result to a JSP.

Web.xml and Struts Config

Web.xml
Web.xml
Struts Config
Struts Config

 

Rest APIs

This just gives the access to the status via APIs

The Framework

This is the main part. It has 2 components.

TaskManager

This is responsible for handing all tasks. The main responsibilities includes:

  1. Singleton access to the same
  2. Managing pending tasks
  3. Managing task updates
  4. Managing thread pool
  5. Synchronizing secured access to the task processing.

Task Processor

This is responsible for handling one task. This could be your business logic class to handle one task. For sake of simplicity I have considered some fake processing and some updates to the task manager.

Context Listener

This calls to handle the memory leak while starting the threads and stopping them post application load and unload.

Context Listener
Context Listener

 

Thats it. Above gets the things going. If we talk about the use cases for this, from the top of my head I can think of:

  1. Handling long running order submission for B2B orders where you cant allow the order to enter database without validation and cant let users stuck on one screen to complete.
  2. Handling bulk actions for a simple operation.

Part 3 will be coming soon with a React GET APIs to get the order updates. Subscribe for more.

Future extensions can include handling resubmit of tasks in case it fails. I will happy to do a POC in future if someone is interested. What are your thoughts on this concept? Feel free to comment how you will implement the same.

The entire code is hosted in Gitlab to try out @ struts-offline-actions!