Add custom service within camunda rest api

Camunda 7 Topics Discussion & Questions
1

Hi, im trying to add my custom functionality for task assignment withing the camunda rest API,
i’m trying to follwot this:

and this:

however, my endpoints are still not reachable.
To simplify things, i want just to add endpoint /task-config/ping to the engine path and call it via localhost:8080/engine-rest/task-config/ping

i have declared the following classes:

@Produces(MediaType.APPLICATION_JSON)
public interface TaskAssignmentConfigRestService {

    public static final String PATH = "/task-config";

    @GET
    @Path("/ping")
    @Produces(MediaType.APPLICATION_JSON)
    String ping();

}

impl:

public class TaskAssignmentConfigServiceImpl extends AbstractRestProcessEngineAware implements TaskAssignmentConfigRestService {

    @Override
    public String ping() {
        return "pong";
    }

}

CustomProcessEngineRestServiceImpl:

@Path("")
public class CustomProcessEngineRestServiceImpl extends AbstractProcessEngineRestServiceImpl {

    public static final String PATH = "";

    @Path(ProcessDefinitionRestService.PATH)
    public ProcessDefinitionRestService getProcessDefinitionService() {
        return super.getProcessDefinitionService(null);
    }

    @Path(TaskAssignmentConfigRestService.PATH)
    public TaskAssignmentConfigRestService getTaskAssignmentConfigService() {
        String rootResourcePath = getRelativeEngineUri(null).toASCIIString();
        TaskAssignmentConfigServiceImpl subResource = new TaskAssignmentConfigServiceImpl(getObjectMapper());
        subResource.setRelativeRootResourceUri(rootResourcePath);
        return subResource;
    }

    @Path(ProcessInstanceRestService.PATH)
    public ProcessInstanceRestService getProcessInstanceService() {
        return super.getProcessInstanceService(null);
    }
}

And registered everything in JerseyConfig

@Configuration
public class CamundaJerseyConfig extends CamundaJerseyResourceConfig {
    private static final Logger log = org.slf4j.LoggerFactory.getLogger(CamundaJerseyConfig.class);

    @Override
    public void afterPropertiesSet() throws Exception {
        registerCamundaRestResources();
        registerAdditionalResources();
    }

    @Override
    protected void registerCamundaRestResources() {
        log.info("Configuring camunda rest api.");
        CamundaRestResources.getResourceClasses().add(TaskAssignmentConfigServiceImpl.class);
        this.registerClasses(CamundaRestResources.getResourceClasses());
        this.registerClasses(CamundaRestResources.getConfigurationClasses());
        this.register(JacksonFeature.class);
        this.registerClasses(TaskAssignmentConfigServiceImpl.class);

        log.info("Finished configuring camunda rest api.");
    }

    @Override
    protected void registerAdditionalResources() {
        register(TaskAssignmentConfigServiceImpl.class);
        CamundaRestResources.getResourceClasses().add(TaskAssignmentConfigServiceImpl.class);
    }

}

also i have added bean definition for jersay config:

@AutoConfigureBefore({ JerseyAutoConfiguration.class })
@AutoConfigureAfter({ CamundaBpmAutoConfiguration.class })
public class CamundaRestJerseyAutoConfiguration extends CamundaBpmRestJerseyAutoConfiguration {

    @Override
    @Bean
    @ConditionalOnMissingBean(CamundaJerseyConfig.class)
    public CamundaJerseyConfig createRestConfig() {
        return new CamundaJerseyConfig();
    }

}

Probably i’m missing something simple, however i can not find what it is, could you help me out?

2

nevermind, figured it out, i mixed up two approaches.
To add custom api, do this:

  1. define interface:

     @Produces(MediaType.APPLICATION_JSON)
 public interface TaskAssignmentConfigRestService {

 public static final String PATH = "/task-config";

 @GET
 @Path("/ping")
 @Produces(MediaType.APPLICATION_JSON)
 String ping();

}

  2. Implement it:

    public class TaskAssignmentConfigServiceImpl extends AbstractRestProcessEngineAware implements TaskAssignmentConfigRestService {

 public TaskAssignmentConfigServiceImpl(String name, ObjectMapper objectMapper) {
     super(name, objectMapper);
 }

 @Override
 public String ping() {
     return "pong";
 }
}

  3. Create it:

    @Path(DefaultProcessEngineRestServiceImpl.PATH)
public class TaskAssignmentConfigDefaultProcessEngineRestServiceImpl extends DefaultProcessEngineRestServiceImpl {


 @Path(TaskAssignmentConfigRestService.PATH)
 public TaskAssignmentConfigRestService getTaskAssignmentConfigService() {
     String rootResourcePath = getRelativeEngineUri(null).toASCIIString();
     TaskAssignmentConfigServiceImpl subResource = new TaskAssignmentConfigServiceImpl(null, getObjectMapper());
     subResource.setRelativeRootResourceUri(rootResourcePath);
     return subResource;
 }
}

  4. register it:

     @Component
 public class CustomJerseyResourceConfiguration extends CamundaJerseyResourceConfig {
 private static final Logger log = org.slf4j.LoggerFactory.getLogger(CustomJerseyResourceConfiguration.class);

 @Override
 protected void registerCamundaRestResources() {
     log.info("Configuring camunda rest api.");
     this.registerClasses(TaskAssignmentConfigDefaultProcessEngineRestServiceImpl.class);
     this.registerClasses(CamundaRestResources.getConfigurationClasses());
     this.register(JacksonFeature.class);
     log.info("Finished configuring camunda rest api.");
 }
}

  5. Easy profit! XD

4 Likes
3

Thanks for posting your solution!

4

Can you please share the complete URL to invoke this service?