JBPM

Since Camel 2.6

Both producer and consumer are supported

The JBPM component provides integration with Business Process Management jBPM. It uses kie-server-client API to interact with jBPM instance over REST. The component supports both producer and consumer.

Maven users will need to add the following dependency to their pom.xml for this component:

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-jbpm</artifactId>
    <version>x.x.x</version><!-- use the same version as your Camel core version -->
</dependency>

URI format

jbpm::events:type:[classifier][?options]

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

The component level is the highest level which holds general and common configurations that are inherited by the endpoints. For example a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

Configuring components can be done with the Component DSL, in a configuration file (application.properties|yaml), or directly with Java code.

Configuring Endpoint Options

Where you find yourself configuring the most is on endpoints, as endpoints often have many options, which allows you to configure what you need the endpoint to do. The options are also categorized into whether the endpoint is used as consumer (from) or as a producer (to), or used for both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL as a type safe way of configuring endpoints.

A good practice when configuring options is to use Property Placeholders, which allows to not hardcode urls, port numbers, sensitive information, and other settings. In other words placeholders allows to externalize the configuration from your code, and gives more flexibility and reuse.

The following two sections lists all the options, firstly for the component followed by the endpoint.

Component Options

The JBPM component supports 3 options, which are listed below.

Name Description Default Type

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

boolean

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

boolean

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

boolean

Endpoint Options

The JBPM endpoint is configured using URI syntax:

jbpm:connectionURL

with the following path and query parameters:

Path Parameters (2 parameters)

Name Description Default Type

connectionURL (common)

Required The URL to the jBPM server.

URL

eventListenerType (common)

Sets the event listener type to attach to.

String

Query Parameters (31 parameters)

Name Description Default Type

attachmentId (common)

attachId to use when retrieving attachments.

Long

contentId (common)

contentId to use when retrieving attachments.

Long

deploymentId (common)

Required The id of the deployment.

String

emitterSendItems (common)

Sets if event produced by emitter should be sent as single items or complete collection.

Boolean

event (common)

the data associated with this event when signalEvent operation is performed.

Object

eventType (common)

the type of event to use when signalEvent operation is performed.

String

identifier (common)

identifier the global identifier.

String

maxNumber (common)

the maximum number of rules that should be fired.

Integer

page (common)

The page to use when retrieving user tasks.

Integer

pageSize (common)

The page size to use when retrieving user tasks.

Integer

processId (common)

the id of the process that should be acted upon.

String

processInstanceId (common)

the id of the process instance.

Long

targetUserId (common)

The targetUserId used when delegating a task.

String

task (common)

The task instance to use with task operations.

Task

taskId (common)

the id of the task.

Long

timeout (common)

A timeout value.

Integer

userId (common)

userId to use with task operations.

String

value (common)

the value to assign to the global identifier.

Object

workItemId (common)

the id of the work item.

Long

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

boolean

exceptionHandler (consumer (advanced))

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored.

ExceptionHandler

exchangePattern (consumer (advanced))

Sets the exchange pattern when the consumer creates an exchange.

Enum values:

  • InOnly

  • InOut

  • InOptionalOut

ExchangePattern

synchronous (consumer (advanced))

Sets whether synchronous processing should be strictly used.

boolean

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

boolean

operation (producer)

The operation to perform.

String

entities (advanced)

The potentialOwners when nominateTask operation is performed.

List

extraJaxbClasses (advanced)

To load additional classes when working with XML.

Class[]

parameters (advanced)

the variables that should be set for various operations.

Map

statuses (filter)

The list of status to use when filtering tasks.

List

password (security)

Password for authentication.

String

userName (security)

Username for authentication.

String

Consumer

jBPM Consumer allows to attach routes to

  • ProcessEventListeners

  • TaskEventListners

  • CaseEventListeners

Path Parameters (3 parameters):

Name Description Default Type

events

Classifier for the consumer to know which type of data it should attach to

URL

type

Type of event listener - supports: process, task, case

String

classifier

Used to distinguish routes for same event type

String

Each route would then receive events when they are being produced by jBPM engine.

Routes can be defined either in global way - on application level or deployed together with business assets projects also knows as KJARs.

Consumers are configured via KieServerExtension that is a pluggable interface to enhance jBPM with additional capabilities. It reacts to different life cycle phases of the KIE Server and by that is able to configure individual endpoints properly.

KJAR routes

Create file named camel-routes.xml in the root folder of your KJAR (src/main/resources) so it will be automatically discovered and Camel Context for given KJAR will be created.

Global routes

Create file name global-camel-routes in the root of the class path of KIE Server. It will be automatically found and registered on every KJAR deployed to KIE Server.

Example camel-routes.xml file that can be placed in the KJAR

<routes xmlns="http://camel.apache.org/schema/spring">

    <route id="processes">
        <from uri="jbpm:events:process:test"/>
        <filter>
          <simple>${in.header.EventType} == 'beforeProcessStarted'</simple>
          <to uri="log:kjar.processes?level=INFO&amp;showBody=true&amp;showHeaders=true"/>
        </filter>
    </route>

    <route id="tasks">
        <from uri="jbpm:events:task:test"/>
        <filter>
          <simple>${in.header.EventType} starts with 'before'</simple>
          <to uri="log:kjar.tasks?level=INFO&amp;showBody=true&amp;showHeaders=true"/>
        </filter>
    </route>
</routes>

Use of jBPM Component in KIE Server

To make use of camel-jbpm component in a KIE Server it is as simple as just adding two jars into KIE Server application

  • camel-core

  • camel-jbpm

then start KIE Server and you will see once booted following information in logs

Camel KIE Server extension has been successfully registered as server extension
....
Route: tasks started and consuming from: jbpm://events:task:test?deploymentId=form-rendering_1.0.0
Total 2 routes, of which 2 are started
Apache Camel 2.23.0-SNAPSHOT (CamelContext: KIE Server Camel context for container evaluation_1.0.0) started in 0.378 seconds
o.k.server.services.impl.KieServerImpl   : Container evaluation_1.0.0 (for release id evaluation:evaluation:1.0.0) successfully started

To make use of jBPM Consumer jBPM deployment descriptor must also define camel specific event listeners of following types

  • new org.apache.camel.component.jbpm.listeners.CamelProcessEventListener()

  • new org.apache.camel.component.jbpm.listeners.CamelTaskEventListener()

  • new org.apache.camel.component.jbpm.listeners.CamelCaseEventListener()

These must be set in either server level of kjar deployment descriptor (use MVEL as resolver type) - see jbpm docs for more details about deployment descriptors.

Producer

Producer is dedicated to interact with jBPM via kie-server-client that uses exposed REST api of jBPM (KIE Server).

URI format

jbpm::hostName[:port][/resourceUri][?options]

Message Headers

Name Default Value Type Description

CamelJBPMValue

null

Object

the value to assign to the global identifier

CamelJBPMOperation

PUT

String

The operation to perform. The operation name must be prefixed with CamelJBPMOperation and the name of the operation. See the full list above. It is case insensitive.

CamelJBPMProcessId

null

String

the id of the process that should be acted upon

CamelJBPMProcessInstanceId

0

Long

the id of the process instance

CamelJBPMParameters

null

Map<String, Object>

the variables that should be set for various operations

CamelJBPMEventType

null

String

the type of event to use when signalEvent operation is performed

CamelJBPMEvent

null

String

The type of the received event. Possible values defined here org.infinispan.notifications.cachelistener.event.Event.Type

CamelJBPMMaxNumber

null

Integer

the maximum number of rules that should be fired

CamelJBPMIdentifier

null

long

identifier the global identifier

CamelJBPMWorkItemId

0

Long

the id of the work item

CamelJBPMTaskId

0

Long

the id of the task

CamelJBPMTask

null

Task

The task instance to use with task operations

CamelJBPMUserId

null

String

userId to use with task operations

CamelJBPMTargetUserId

null

String

The targetUserId used when delegating a task

CamelJBPMLanguage

null

String

The language to use when filtering user tasks

CamelJBPMAttachmentId

0

Long

attachId to use when retrieving attachments

CamelJBPMContentId

0

Long

contentId to use when retrieving attachments

CamelJBPMEntityList

null

List<String>

The potentialOwners when nominateTask operation is performed

CamelJBPMStatusList

null

List<String>

The list of status to use when filtering tasks

Example

Below is an example route that starts a business process with id evaluation. To run this example you need jBPM to run locally, easiest is to use single zip distribution - downloaded from jbpm.org. Next, start it and import Evaluation sample project, build and deploy. Once done this test can be ran out of the box.

Map<String, Object> params = new HashMap<>();
params.put("employee", "wbadmin");
params.put("reason", "Camel asks for it");

from("direct:start")
        .setHeader(JBPMConstants.PROCESS_ID, constant("evaluation"))
        .setHeader((JBPMConstants.PARAMETERS, params))
        .to("jbpm:http://localhost:8080/kie-server/services/rest/server?userName=wbadmin&password=wbadmin
        &deploymentId=evaluation");

Spring Boot Auto-Configuration

When using jbpm with Spring Boot make sure to use the following Maven dependency to have support for auto configuration:

<dependency>
  <groupId>org.apache.camel.springboot</groupId>
  <artifactId>camel-jbpm-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 4 options, which are listed below.

Name Description Default Type

camel.component.jbpm.autowired-enabled

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

Boolean

camel.component.jbpm.bridge-error-handler

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

Boolean

camel.component.jbpm.enabled

Whether to enable auto configuration of the jbpm component. This is enabled by default.

Boolean

camel.component.jbpm.lazy-start-producer

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

Boolean