A lightweight version of Zeebe from Camunda. It bundles Zeebe's workflow engine including some required libraries so that it can be included in Java projects.

Important note: This project is a community effort not maintained by Camunda and not supported for production usage. Use at your own risk. Additionally, there is also the EZE community project, providing an in-memory engine mostly used for JUnit tests. The main differences of EZE Java are the usage of Java instead of Kotlin, and the use of RockDB for storage instead of a complete in-memory solution.

Features:

• Support Zeebe clients and exporters
• Use RocksDB database for the state

Add one of the following dependency to your project (i.e. Maven pom.xml):

For the embedded engine:

<dependency>
  <groupId>org.camunda.community</groupId>
  <artifactId>eze-java</artifactId>
  <version>1.0.1-SNAPSHOT</version>
</dependency>

For the Spring Boot Starter:

<dependency>
  <groupId>org.camunda.community</groupId>
  <artifactId>spring-eze-starter</artifactId>
  <version>1.0.1-SNAPSHOT</version>
</dependency>

Use the factory to create a new engine.

ZeebeEngine engine = EngineFactory.create()

or

BrokerCfg cfg = new BrokerCfg();
ZeebeEngine engine = EngineFactory.create(cfg)


engine.start()
// ...
engine.stop()

Please note, using the spring-eze-starter will automatically manage the life cycle of the ZeebeEngine (start, stop)

The engine includes an embedded gRPC gateway to support interactions with Zeebe clients.

Use the factory method of the engine to create a preconfigured Zeebe client.

ZeebeClient client = engine.createClient()

Or, create your own Zeebe client using the provided gateway address from the engine.

ZeebeClient client = ZeebeClient.newClientBuilder()
  .gatewayAddress(engine.getGatewayAddress())
  .usePlaintext()
  .build()

Or, inject the ZeebeClient with Spring Boot Starter

@Autowired
private ZeebeClient client;

The spring-eze-starter is a Spring Boot Starter application. The configuration can be changed an application.yaml file.

eze:
  network:
    host: 0.0.0.0
    port: 26500
  data:
    directory: data
    logSegmentSize: 10MB
    snapshotPeriod: 5m
  exporters:
    elasticsearch:
      class-name: io.camunda.zeebe.exporter.ElasticsearchExporter
      args:
        url: http://localhost:9200
        index:
          prefix: zeebe-record
          createTemplate: true

          numberOfShards: 3
          numberOfReplicas: 0

          command: false
          event: true
          rejection: false

          deployment: false
          process: true
          error: true
          incident: true
          job: true
          jobBatch: false
          message: false
          messageSubscription: false
          variable: true
          variableDocument: true
          processInstance: true
          processInstanceCreation: false
          processMessageSubscription: false

There is a full example, including test cases. Further, you might want to have a look into the example folder.