Simple Project

This project is to provide a starting point to integrate Activiti into some existing code. We intend to show how we can embed Activiti into an existing Spring Boot application, and demonstrate that Activiti can invoke logic on Spring Beans and vice versa (i.e. Activiti -> Custom Logic and Custom Logic -> Activiti)

Realistically, in a production system, we probably wouldn't include everything here in a single webapp - I imagine that any UI outside of Activiti, and our own REST Api might be hosted elsewhere. Still, I want to know how to control it all in one place - so that we have that option open to us.

Building and running

We have used gradle + Spring Boot to allow us to create a simple single war deployment. This git repo contains all that you need to build and run the application - all the necessary dependencies, including gradle itself, will be downloaded as necessary. All that is needed is java 7 (or later) jdk, and access to the internet to download the dependencies. (If internet access is behind a proxy, and it doesn't work out of the box, see the Gradle Docs for more details.

To run the application

./gradlew bootRun

To build an executable WAR:

./gradlew bootRePackage

The resulting war (build/libs/simple-project.war) can either be deployed into a Web Application Server (e.g. Tomcat) or executed directly

java -jar build/libs/simple-project.war

Entry Point

com.example.embedsample.Application is the main Spring Boot entry point. It registers two separate Spring Dispatcher servlets, one at /main-ui (the user interface) and one at /special-api (a REST Api)

There is a simple front page at the root of the application, providing accesss to both main UI pages. It also has a disable placeholder link for the Activiti UI

Business Logic

com.example.embedsample.CompanyService provides access to the domain class. It represents business logic that may be called either from the REST Api or an Activiti process. The bean name is companyService

com.example.embedsample.AccountsUploadService will deal with the business logic of a file upload. It is intended that it will notify an Activity process instance of the presence of a file, via a message. Hopefuly, we will also be able to add the file to the process instance too. The bean name is accountsUploadService

Web Controllers

There are two separate dispatcher servlets for two separate Web Contexts within the application.

REST Api

The com.example.embedsample.web.rest context is mapped to /special-api; it provides access to the business logic

/special-api/companies provides access to a list of companies /special-api/companies/xxxx provides data for a specic company, where xxx is the company registration number

Main UI

The com.example.embedsample.web.mainui context is mapped to /main-ui. It uses the REST Api above to provide the backend functionality. The front end is built from HTML + Bootstrap + JQuery; by using Thymeleaf templates, we've made it a little easier to prototype whilst developing, and also access embedded resources using webjars

/main-ui is a simple table of companies. By selecting a company, further information is displayed. /main-ui/upload presents a form with an execution ID and a file-selector. When the form is posted, the CompaniesAPIController will pass the information on to the AccountsUploadService