spring

Spring Integration

This sample aims to show how to configure Hazelcast Jet as a Spring bean. There are two ways to achieve this:

1. Programmatic (annotation-based) configuration. This is the easiest way to configure Hazelcast Jet, simply create a config class which you can provide JetInstance as a bean with @Bean annotation. Inside the method annotated with @Bean you can create and configure JetInstance programmatically.

2. Declarative (xml) configuration. You can configure Hazelcast Jet using an xml file too. Here you have 2 choices:

• using spring core bean definitions. (application-context.xml)

• using Hazelcast Jet provided schema for bean definitions. (application-context-with-schema.xml)

  You should have hazelcast-jet-spring.jar in your classpath to use Hazelcast Jet bean definitions. You will have <jet:instance> and <jet:client> bean definitions to create/configure Hazelcast Jet Instance and Hazelcast Jet Client respectively. You will have other bean definitions like <jet:map>, <jet:list> and <jet:hazelcast> to obtain IMapJet, IListJet and the underlying HazelcastInstance as a spring bean.

Spring Boot Integration

You can integrate Hazelcast Jet with Spring Boot easily. The approach is very similar to the programmatic configuration. You need to have a config class which has @SpringBootApplication annotation.

@RestController
public class SpringBootSample {

    @Autowired
    JetInstance instance;

    public static void main(String[] args) {
        SpringApplication.run(AppConfig.class, args);
    }

    @RequestMapping("/submitJob")
    public void submitJob() {
        Pipeline pipeline = Pipeline.create();
        pipeline.drawFrom(CustomSourceP.customSource())
                .drainTo(Sinks.logger());

        JobConfig jobConfig = new JobConfig()
                .addClass(SpringBootSample.class)
                .addClass(CustomSourceP.class);
        instance.newJob(pipeline, jobConfig).join();
    }

}

@SpringAware annotation

Hazelcast Jet manages the life-cycle of processors itself, which means creation and initialization of processors are done on each member without any interference of spring context. If you want to inject spring context to your processors you should mark them with @SpringAware annotation. Here is a custom source example.

You have to configure Hazelcast Jet to use SpringManagedContext to enable @SpringAware annotation. If configured, the SpringManagedContext checks the processor for @SpringAware annotation. If the annotation is present then it will inject spring context.

    @Bean
    public ManagedContext managedContext() {
        return new SpringManagedContext();
    }

    @Bean
    public JetInstance instance() {
        Config config = new Config()
                .setManagedContext(managedContext());
        JetConfig jetConfig = new JetConfig()
                .setHazelcastConfig(config);
        return Jet.newJetInstance(jetConfig);
    }

    <hz:config>
        ...
        <hz:spring-aware/>
        ...
    </hz:config>