spring-servlet-pa-wildfly

Spring 5 Servlet Process Application (using WildFly 26)

This example demonstrates how to deploy a Spring 5 powered Web application which

• Includes a @ProcessApplication class and some BPMN 2.0 processes
• Starts a Spring Web application context
• Uses a shared container managed Process Engine and Spring Beans as expression and delegate expression in the processes

Why is this example interesting?

This example shows how to combine a @ProcessApplication class, a processes.xml and a Spring applicationContext into a fully-fledged Process Application with all its advantages, including a managed container shared Process Engine paired with the power of Spring Beans inside your processes.

Show me the important parts!

We create a Process Application class which extends the ServletProcessApplication and annotate it with @ProcessApplication, so the Camunda Platform can pick it up and register the Process Application without any further action:

@ProcessApplication
public class SpringServletProcessApplication extends ServletProcessApplication {
  ...
}

Through the META-INF/processes.xml, we can define Process Archives and additional options, like creating new Process Engines when deploying the Process Application:

<?xml version="1.0" encoding="UTF-8"?>
<process-application
    xmlns="http://www.camunda.org/schema/1.0/ProcessApplication"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.camunda.org/schema/1.0/ProcessApplication http://www.camunda.org/schema/1.0/ProcessApplication ">

  <process-archive>
    <properties>
      <property name="isDeleteUponUndeploy">true</property>
    </properties>

  </process-archive>

</process-application>

Additionally, you have to package the camunda-engine-spring module as a maven compile time dependency like:

<dependency>
  <groupId>org.camunda.bpm</groupId>
  <artifactId>camunda-engine-spring</artifactId>
  <version>${camunda.version}</version>
  <scope>compile</scope>
</dependency>

How to use it?

1. Build it with Maven and Java 11.

mvn clean verify

This will create a Camunda Platform WildFly distribution and execute the included Arquillian test.

3. Watch out for this console log:

INFO  [org.camunda.bpm.example.spring.servlet.pa.SpringServletProcessApplication] (MSC service thread 1-5) Invoking @PostDeploy annotation in org.camunda.bpm.example.spring.servlet.pa.SpringServletProcessApplication
Starting testResolveBean processdefinition
INFO  [org.camunda.bpm.example.spring.servlet.pa.ExampleBean] (MSC service thread 1-5) org.camunda.bpm.example.spring.servlet.pa.ExampleBean is currently invoked.
INFO  [org.camunda.bpm.example.spring.servlet.pa.SpringServletProcessApplication] (MSC service thread 1-5) Starting testResolveBeanFromJobExecutor processdefinition
INFO  [org.camunda.bpm.example.spring.servlet.pa.ExampleDelegateBean] (pool-10-thread-7) org.camunda.bpm.example.spring.servlet.pa.ExampleDelegateBean is currently invoked.
...
INFO  [org.camunda.bpm.example.spring.servlet.pa.SpringServletProcessApplication] (MSC service thread 1-1) Invoking @PreUndeploy annotation in org.camunda.bpm.example.spring.servlet.pa.SpringServletProcessApplication
Undeploying SpringServletProcessApplication-Example