Category: Development

In this short tutorial I will explain a few basic design patterns helping you to build really good Business Process Management Systems based on Imixs-Workfow. For these patterns it does not matter if you build a app just with the Imixs-Workflow core engine or if you use Imixs-Office-Workflow. All patterns explain very basic concepts which will help you a lot in understanding to build and maintain your business application. So lets start!

Continue reading “How to Build Good Workflow Applications”

To setup a database realm (JDBCRealm) in Payara Micro is a little bit tricky because some settings have changed in the past and so there is no clear updated example. This blog post shows a configuration example for Payara 5.2 in combination with a data source based on the Workflow project Imixs-Office-Workflow.

<security-service activate-default-principal-to-role-mapping="true" jacc="simple"
   audit-enabled="true" default-realm="jdbcRealm">

<auth-realm classname="com.sun.enterprise.security.auth.realm.file.FileRealm" name="admin-realm">
<property value="${com.sun.aas.instanceRoot}/config/admin-keyfile" name="file" />
<property value="fileRealm" name="jaas-context" />
</auth-realm>

<!-- Imixs file realm configuraiton START -->
<auth-realm classname="com.sun.enterprise.security.auth.realm.jdbc.JDBCRealm" name="jdbcRealm">
<property name="jaas-context" value="jdbcRealm"></property>
<property name="encoding" value="Hex"></property>
<property name="password-column" value="password"></property>
<property name="datasource-jndi" value="jdbc/office"></property>
<property name="group-table" value="userid_usergroup"></property>
<property name="user-table" value="userid"></property>
<property name="group-name-column" value="group_id"></property>
<property name="group-table-user-name-column" value="id"></property>
<property name="digest-algorithm" value="SHA-256"></property>
<property name="user-name-column" value="id"></property>
</auth-realm>
<!-- Imixs file realm configuraiton END -->

....
<audit-module classname="com.sun.enterprise.security.ee.Audit" name="default">
<property name="auditOn" value="true" />
</audit-module>
.....
</security-service>

Take care about the property “group-table-user-name-column”. This property is new and specifies the column name for the userid within the group table.

Another important setting is the “default-realm” in the security-service tag. This property must be set to the name of the jdbcRealm (in my case “jdbcRealm”).

Enable Security Audit

To get more information what is happening during the authentication you can enable the security-service audit with the attribute

audit-enabled="true"

and the audit for the security module with the property ‘auditOn’

<audit-module classname="com.sun.enterprise.security.ee.Audit" name="default">
   <property name="auditOn" value="true" />
</audit-module>

With the latest version 5.1.0 the Imixs-Workflow project introduces a BPMN based Rule Engine.

The BPMN Rule Engine uses Conditional Events to evaluate a business rule. This is a powerful mechanism to describe rules in a BPMN model and evaluate a given workitem.

The BPMN Rule Engine provides an easy way to describe also complex business rules based on a visual model. The rules are evaluated as a chain of conditional events. The engine evaluates the data of a given workitem.

A single condition is defined in a conditional sequence flow. The conditional expression is based on JavaScript but other Script languages are also supported.

To initialize a BPMN Rule Engine a Imixs BPMN Model instance need to be loaded first.

bpmnRuleEngine=new BPMNRuleEngine(model);

workitem = new ItemCollection().model(MODEL_VERSION).task(100).event(10);
workitem.setItemValue("a", 1);
workitem.setItemValue("b", "DE");

// evaluate rule
Assert.assertEquals(200, bpmnRuleEngine.eval(workitem));

The model instance can either be taken from a running instance of the Imixs-Workflow engine or loaded on demand from the file system:

// load BPMN model from input stream
Model model = BPMNParser.parseModel(inputStream, "UTF-8");

The workitem can contain any kind of data to be evaluated by the business rules. Internally the Imixs BPMN Rule Engine is based on the Core-RuleEngine which supports various script languages to describe a rule.

The example BPMN model can be downloaded from Github . Install the Imixs-BPMN Modeler to examine the example.

More details about the Imixs BPMN Rule Engine can be find on the project site.

With the upcomming version 5.0.0 the Imixs-Workflow engine is integrated into the Eclipse Micoroprofile API.

The Enterprise Java technology has evolved with the industry for nearly two decades to support distributed application architectures based on RMI/IIOP, Web Services, and REST. The MicroProfile is the next step in that evolution. Since Imixs based on Java Enterprise technology stack, it is consistently to expand the technology to the new standard. As a developer this will bring you more features and a much smarter way to run the Imixs-Workflow engine within a microservice architecture.

The Version 5.0.0 will provide the following APIs:

• Metrics – This allows you to monitor Imixs-Workflow with Tools like Prometheus or Grafana
• Health Check – The Health Check API can be used to probe the state of an Imixs-Workflow instance from another machine (i.e. a kubernetes service controller)
• Config API – Configuration data can now come from different locations

We will provide soon more documentation and examples on how you can run Imixs-Workflow in a Microservice Infrastructure. If you have questions please joint our community!