How to implement Activiti REST API with Spring Boot Example

In this tutorial, we’re gonna look at an example that uses Activiti REST API with Spring Boot.

Related Articles:
Introduction to Activiti – a Java BPM Engine
How to start Activiti + Spring JPA with Spring Boot

I. Activiti REST API Overview

Activiti Engine includes a REST API that can be used by:
– deploying the activiti-rest.war file to a servlet container,
– or including the servlet and it’s mapping in the application and add all activiti-rest dependencies to the classpath.

By default the Activiti Engine will connect to an in-memory H2 database, so with Spring Boot, we just need to add dependency as below to make it run:

Activiti REST API supports:

  • Deployment: get/create/delete Deployments, get resources inside a Deployment.
  • Process Definition: get one or list of Process Definitions, get resource content or BPMN model of a Process Definition, activate/suspend, get/add/delete candidate starters.
  • Model: get/update/create/delete Models, get/set editor source for a Model.
  • Process Instance: get/delete/activate/suspend Process Instances, add/remove Users, get/create/update Variables.
  • Execution: get Executions, execute an action or get active activities, query, get/create/update Variables.
  • Task: get/update/delete Tasks, query for Tasks, get/create/update Variables, get/create/delete identity links, get Events, get/create/delete Attachments.
  • History: get/delete/query for Historic Process Instances, Task Instances, Activities Instances, Variables Intances.
  • User & Group: get/create/update/delete information.
  • Database Table, Engine, Runtime, Job

For more details, please visit: Activiti User Guide – REST API

In the example, we will test some of them to see how it works.

II. Practice

1. Technology

– Java 1.8
– Maven 3.3.9
– Spring Tool Suite – Version 3.8.4.RELEASE
– Spring Boot: 1.5.3.RELEASE

2. Step by step
2.1 Create Spring Boot project

Using Spring Tool Suite/Eclipse to create Project and add Dependencies to pom.xml file:

2.2 Define Process

Under src/main/resources, create processes folder and add simple-process.bpmn20.xml file:

We use ${person} expression and activiti:assignee attribute for assigning task.

2.3 Initialize User

By default, all Activiti REST resources require a valid User to be authenticated. So we should create an admin User. Open Application class, add Bean for initializing User:

Basic HTTP access authentication is used, so we always include a authorized username & password in the request url.

More about Activiti Services at: Introduction to Activiti – a Java BPM Engine

2.4 Run & Check Result

– Config maven build:
clean install
– Run project with mode Spring Boot App
– Check results:

List of Deployments:
curl -u admin:admin http://localhost:8080/repository/deployments

List resources in a deployment:
curl -u admin:admin http://localhost:8080/repository/deployments/1/resources

List of process definitions:
curl -u admin:admin http://localhost:8080/repository/process-definitions

Get BPMN model (by processId):
curl -u admin:admin http://localhost:8080/repository/process-definitions/simpleProcess:1:3/model

Start Process:
curl -u admin:admin -H "Content-Type: application/json" -d '{"processDefinitionKey":"simpleProcess", "variables": [ {"name":"person", "value":"John"}]}' http://localhost:8080/runtime/process-instances

We have also sent Variables Information {“person”:”John”}. This request returns a Process Instance:

List of variables by Process Instance ID
curl -u admin:admin http://localhost:8080/runtime/process-instances/4/variables

List of tasks:
curl -u admin:admin http://localhost:8080/runtime/tasks

Add Variables to Task (by Id):
curl -u admin:admin -H "Content-Type: application/json" -d '[{"name" : "newTaskVariable", "scope" : "local", "type" : "string", "value" : "This is variable Value"}]' http://localhost:8080/runtime/tasks/9/variables

Identity Links (by Id):
curl -u admin:admin http://localhost:8080/runtime/tasks/9/identitylinks

Complete Task (by Id):
curl -u admin:admin -H "Content-Type: application/json" -d '{"action" : "complete"}' http://localhost:8080/runtime/tasks/9

Historic process instance:
curl -u admin:admin http://localhost:8080/history/historic-process-instances/4

III. Source code

SpringRestActiviti



By grokonez | May 15, 2017.


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5 thoughts on “How to implement Activiti REST API with Spring Boot Example”

  1. Hi,
    I downloaded your code source. And it doesn’t work until I removed activiti rest – api. and by removing activit-rest-api we will not have acces to Rest api. can you suggest any solution?

    1. Hi WAJDI,

      Make sure that you didn’t deploy the activiti-rest.war file to a servlet container before.
      Then just follow step by step to make project run (all activiti-rest dependencies will be added to the classpath automatically).
      I have checked the source code again and it works well.

      If you cannot make thing done, notice us again and show your problem more clearly.

      Best Regard,

  2. I downloaded the code and tried to post using the below command.

    curl -u admin:admin -H “Content-Type: application/json” -d ‘{“processDefinitionKey”:”simpleProcess”, “variables”: [ {“name”:”person”, “value”:”John”}]}’ http://localhost:8080/runtime/process-instances

    I am getting below error
    ,
    {“message”:”Bad request”,”exception”:”Either processDefinitionId, processDefinitionKey or message is required.”}

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