This section guides you through a tutorial of creating a BPMN process using the WSO2 Developer Studio and covers the following areas:
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- Eclipse JavaEE luna with WSO2 Developer Studio ( 3.8.0 or later ) installed.
- Activiti Eclipse Designer plugin
- WSO2 Business Process Server 3.5.1 or higher (As BPMN runtime.)
Creating the process and service task
- Install the Activiti Eclipse Designer plugin. For instructions on installation, see the Activiti user guide.
- Open Eclipse and go to File>New>Other and search for the Activiti project wizard to create a new Activiti project.
- Go to File>New>Other and search for the Activiti Diagram wizard to create a new Activiti diagram.
- Select the
<Activiti_Project>/src/main/resources/diagrams
directory as the parent folder. - Add a a Start event, Service Task and End Event as seen below to create a basic process. Link each activity by hovering over the element, selecting the arrow sign and dragging it to the connecting element.
- Create a Java project for HelloWorld Service Task by navigating to File>New>Other and searching for the Java Project Wizard.
- Right-click on the project "HelloWorldServiceTask" and go to Build Path>Configure Build Path.
- Click on Add External JARs under the Libraries tab and add the
activiti-all_5.19.0.wso2v2.jar
file ( or later version ) found at the<BPS_Home>/repository/components/plugins
directory.
- Go to File>New>Other and search for the Package wizard to create a Java package and name it "org.wso2.bpmn.helloworld.v1".
- Go to File>New>Class to create a Java Class for HelloWorld Service task implementation.
- Add
org.activiti.engine.delegate.JavaDelegate
interface to your class. Implement HelloWorld Service Task following business logic in the
HelloWorldServiceTaskV1.java
file as seen below.Code Block language java package org.wso2.bpmn.helloworld.v1; import org.activiti.engine.delegate.DelegateExecution; import org.activiti.engine.delegate.JavaDelegate; /** * Hello World Service Task- V1. */ public class HelloWorldServiceTaskV1 implements JavaDelegate { @Override public void execute(DelegateExecution arg0) throws Exception { System.out.println("Hello World ...!!!"); } }
Configure HelloWorld Service Task Class name in properties.
Panel title Best Practices Note title Versioning When you create a Java Service Task, version your java package or classes by adding version number into Java Package path or Class name. This is useful when you have multiple versions of the same workflow and you are changing Service task business logic in each process version. Having versions will avoid business logic changes in service tasks from affecting new or running process instances which are created from the old process version. An example of this can be seen below.
Code Block language java title Version 1 package org.wso2.bpmn.helloworld.v1; import org.activiti.engine.delegate.DelegateExecution; import org.activiti.engine.delegate.JavaDelegate; /** * Hello World Service Task- V1. */ public class HelloWorldServiceTaskV1 implements JavaDelegate { @Override public void execute(DelegateExecution arg0) throws Exception { System.out.println("Hello World ...!!!"); } }
Code Block language java title Version 2 package org.wso2.bpmn.helloworld.v2; import org.activiti.engine.delegate.DelegateExecution; import org.activiti.engine.delegate.JavaDelegate; /** * Hello World Service Task - Version 2. */ public class HelloWorldServiceTaskV2 implements JavaDelegate { @Override public void execute(DelegateExecution arg0) throws Exception { // In version 2, Hello World string is improved. System.out.println("Hello World ...!!! This is Second version of HelloWorld BPMN process."); } }
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