Olingo4 Component

Available as of Camel version 2.19

The Olingo4 component utilizes Apache Olingo version 4.0 APIs to interact with OData 4.0 compliant service. Since version 4.0 OData is OASIS standard and number of popular open source and commercial vendors and products support this protocol. A sample list of supporting products can be found on the OData website.

The Olingo4 component supports reading entity sets, entities, simple and complex properties, counts, using custom and OData system query parameters. It supports updating entities and properties. It also supports submitting queries and change requests as a single OData batch operation.

The component supports configuring HTTP connection parameters and headers for OData service connection. This allows configuring use of SSL, OAuth2.0, etc. as required by the target OData service.

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

    <dependency>
        <groupId>org.apache.camel</groupId>
        <artifactId>camel-olingo4</artifactId>
        <version>x.x.x</version>
        <!-- use the same version as your Camel core version -->
    </dependency>

URI format

    olingo4://endpoint/<resource-path>?[options]

Olingo4 Options

The Olingo4 component supports 3 options, which are listed below.

Name Description Default Type

configuration (common)

To use the shared configuration

Olingo4Configuration

useGlobalSslContext Parameters (security)

Enable usage of global SSL context parameters.

false

boolean

basicPropertyBinding (advanced)

Whether the component should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities

false

boolean

The Olingo4 endpoint is configured using URI syntax:

olingo4:apiName/methodName

with the following path and query parameters:

Path Parameters (2 parameters):

Name Description Default Type

apiName

Required What kind of operation to perform

Olingo4ApiName

methodName

Required What sub operation to use for the selected operation

String

Query Parameters (33 parameters):

Name Description Default Type

connectTimeout (common)

HTTP connection creation timeout in milliseconds, defaults to 30,000 (30 seconds)

30000

int

contentType (common)

Content-Type header value can be used to specify JSON or XML message format, defaults to application/json;charset=utf-8

application/json;charset=utf-8

String

filterAlreadySeen (common)

Set this to true to filter out results that have already been communicated by this component.

false

boolean

httpAsyncClientBuilder (common)

Custom HTTP async client builder for more complex HTTP client configuration, overrides connectionTimeout, socketTimeout, proxy and sslContext. Note that a socketTimeout MUST be specified in the builder, otherwise OData requests could block indefinitely

HttpAsyncClientBuilder

httpClientBuilder (common)

Custom HTTP client builder for more complex HTTP client configuration, overrides connectionTimeout, socketTimeout, proxy and sslContext. Note that a socketTimeout MUST be specified in the builder, otherwise OData requests could block indefinitely

HttpClientBuilder

httpHeaders (common)

Custom HTTP headers to inject into every request, this could include OAuth tokens, etc.

Map

inBody (common)

Sets the name of a parameter to be passed in the exchange In Body

String

proxy (common)

HTTP proxy server configuration

HttpHost

serviceUri (common)

Target OData service base URI, e.g. http://services.odata.org/OData/OData.svc

String

socketTimeout (common)

HTTP request timeout in milliseconds, defaults to 30,000 (30 seconds)

30000

int

sslContextParameters (common)

To configure security using SSLContextParameters

SSLContextParameters

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.

false

boolean

sendEmptyMessageWhenIdle (consumer)

If the polling consumer did not poll any files, you can enable this option to send an empty message (no body) instead.

false

boolean

splitResult (consumer)

For endpoints that return an array or collection, a consumer endpoint will map every element to distinct messages, unless splitResult is set to false.

true

boolean

exceptionHandler (consumer)

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)

Sets the exchange pattern when the consumer creates an exchange.

ExchangePattern

pollStrategy (consumer)

A pluggable org.apache.camel.PollingConsumerPollingStrategy allowing you to provide your custom implementation to control error handling usually occurred during the poll operation before an Exchange have been created and being routed in Camel.

PollingConsumerPoll Strategy

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.

false

boolean

basicPropertyBinding (advanced)

Whether the endpoint should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities

false

boolean

synchronous (advanced)

Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported).

false

boolean

backoffErrorThreshold (scheduler)

The number of subsequent error polls (failed due some error) that should happen before the backoffMultipler should kick-in.

int

backoffIdleThreshold (scheduler)

The number of subsequent idle polls that should happen before the backoffMultipler should kick-in.

int

backoffMultiplier (scheduler)

To let the scheduled polling consumer backoff if there has been a number of subsequent idles/errors in a row. The multiplier is then the number of polls that will be skipped before the next actual attempt is happening again. When this option is in use then backoffIdleThreshold and/or backoffErrorThreshold must also be configured.

int

delay (scheduler)

Milliseconds before the next poll. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour).

500

long

greedy (scheduler)

If greedy is enabled, then the ScheduledPollConsumer will run immediately again, if the previous run polled 1 or more messages.

false

boolean

initialDelay (scheduler)

Milliseconds before the first poll starts. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour).

1000

long

runLoggingLevel (scheduler)

The consumer logs a start/complete log line when it polls. This option allows you to configure the logging level for that.

TRACE

LoggingLevel

scheduledExecutorService (scheduler)

Allows for configuring a custom/shared thread pool to use for the consumer. By default each consumer has its own single threaded thread pool.

ScheduledExecutor Service

scheduler (scheduler)

To use a cron scheduler from either camel-spring or camel-quartz component

none

String

schedulerProperties (scheduler)

To configure additional properties when using a custom scheduler or any of the Quartz, Spring based scheduler.

Map

startScheduler (scheduler)

Whether the scheduler should be auto started.

true

boolean

timeUnit (scheduler)

Time unit for initialDelay and delay options.

MILLISECONDS

TimeUnit

useFixedDelay (scheduler)

Controls if fixed delay or fixed rate is used. See ScheduledExecutorService in JDK for details.

true

boolean

Spring Boot Auto-Configuration

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

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-olingo4-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 16 options, which are listed below.

Name Description Default Type

camel.component.olingo4.basic-property-binding

Whether the component should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities

false

Boolean

camel.component.olingo4.configuration.api-name

What kind of operation to perform

Olingo4ApiName

camel.component.olingo4.configuration.connect-timeout

HTTP connection creation timeout in milliseconds, defaults to 30,000 (30 seconds)

30000

Integer

camel.component.olingo4.configuration.content-type

Content-Type header value can be used to specify JSON or XML message format, defaults to application/json;charset=utf-8

application/json;charset=utf-8

String

camel.component.olingo4.configuration.filter-already-seen

Set this to true to filter out results that have already been communicated by this component.

false

Boolean

camel.component.olingo4.configuration.http-async-client-builder

Custom HTTP async client builder for more complex HTTP client configuration, overrides connectionTimeout, socketTimeout, proxy and sslContext. Note that a socketTimeout MUST be specified in the builder, otherwise OData requests could block indefinitely

HttpAsyncClientBuilder

camel.component.olingo4.configuration.http-client-builder

Custom HTTP client builder for more complex HTTP client configuration, overrides connectionTimeout, socketTimeout, proxy and sslContext. Note that a socketTimeout MUST be specified in the builder, otherwise OData requests could block indefinitely

HttpClientBuilder

camel.component.olingo4.configuration.http-headers

Custom HTTP headers to inject into every request, this could include OAuth tokens, etc.

Map

camel.component.olingo4.configuration.method-name

What sub operation to use for the selected operation

String

camel.component.olingo4.configuration.proxy

HTTP proxy server configuration

HttpHost

camel.component.olingo4.configuration.service-uri

Target OData service base URI, e.g. http://services.odata.org/OData/OData.svc

String

camel.component.olingo4.configuration.socket-timeout

HTTP request timeout in milliseconds, defaults to 30,000 (30 seconds)

30000

Integer

camel.component.olingo4.configuration.split-result

For endpoints that return an array or collection, a consumer endpoint will map every element to distinct messages, unless splitResult is set to false.

true

Boolean

camel.component.olingo4.configuration.ssl-context-parameters

To configure security using SSLContextParameters

SSLContextParameters

camel.component.olingo4.enabled

Enable olingo4 component

true

Boolean

camel.component.olingo4.use-global-ssl-context-parameters

Enable usage of global SSL context parameters.

false

Boolean

Producer Endpoints

Producer endpoints can use endpoint names and options listed next. Producer endpoints can also use a special option inBody that in turn should contain the name of the endpoint option whose value will be contained in the Camel Exchange In message. The inBody option defaults to data for endpoints that take that option.

Any of the endpoint options can be provided in either the endpoint URI, or dynamically in a message header. The message header name must be of the format CamelOlingo4.<option>. Note that the inBody option overrides message header, i.e. the endpoint option inBody=option would override a CamelOlingo4.option header. In addition, query parameters can be specified

Note that the resourcePath option can either in specified in the URI as a part of the URI path, as an endpoint option ?resourcePath=<resource-path> or as a header value CamelOlingo4.resourcePath. The OData entity key predicate can either be a part of the resource path, e.g. Manufacturers('1'), where '__1' is the key predicate, or be specified separately with resource path Manufacturers and keyPredicate option '1'.

Endpoint Options HTTP Method Result Body Type

batch

data, endpointHttpHeaders

POST with multipart/mixed batch request

java.util.List<org.apache.camel.component.olingo4.api.batch.Olingo4BatchResponse>

create

data, resourcePath, endpointHttpHeaders

POST

org.apache.olingo.client.api.domain.ClientEntity for new entries org.apache.olingo.commons.api.http.HttpStatusCode for other OData resources

delete

resourcePath, endpointHttpHeaders

DELETE

org.apache.olingo.commons.api.http.HttpStatusCode

merge

data, resourcePath, endpointHttpHeaders

MERGE

org.apache.olingo.commons.api.http.HttpStatusCode

patch

data, resourcePath, endpointHttpHeaders

PATCH

org.apache.olingo.commons.api.http.HttpStatusCode

read

queryParams, resourcePath, endpointHttpHeaders

GET

Depends on OData resource being queried as described next

update

data, resourcePath, endpointHttpHeaders

PUT

org.apache.olingo.commons.api.http.HttpStatusCode

action

data, resourcePath, endpointHttpHeaders

POST

org.apache.olingo.client.api.domain.ClientEntity for action’s that have a "ReturnType" defined org.apache.olingo.commons.api.http.HttpStatusCode otherwise

Endpoint HTTP Headers

The component level configuration property httpHeaders supplies static HTTP header information. However, some systems requires dynamic header information to be passed to and received from the endpoint. A sample use case would be systems that require dynamic security tokens. The endpointHttpHeaders and responseHttpHeaders endpoint properties provides this capability. Set headers that need to be passed to the endpoint in the CamelOlingo4.endpointHttpHeaders property and the response headers will be returned in a CamelOlingo4.responseHttpHeaders property. Both properties are of the type java.util.Map<String, String>.

OData Resource Type Mapping

The result of read endpoint and data type of data option depends on the OData resource being queried, created or modified.

OData Resource Type Resource URI from resourcePath and keyPredicate In or Out Body Type

Entity data model

$metadata

org.apache.olingo.commons.api.edm.Edm

Service document

/

org.apache.olingo.client.api.domain.ClientServiceDocument

OData entity set

<entity-set>

org.apache.olingo.client.api.domain.ClientEntitySet

OData entity

<entity-set>(<key-predicate>)

org.apache.olingo.client.api.domain.ClientEntity for Out body (response) java.util.Map<String, Object> for In body (request)

Simple property

<entity-set>(<key-predicate>)/<simple-property>

org.apache.olingo.client.api.domain.ClientPrimitiveValue

Simple property value

<entity-set>(<key-predicate>)/<simple-property>/$value

org.apache.olingo.client.api.domain.ClientPrimitiveValue

Complex property

<entity-set>(<key-predicate>)/<complex-property>

org.apache.olingo.client.api.domain.ClientComplexValue

Count

<resource-uri>/$count

java.lang.Long

Consumer Endpoints

Only the read endpoint can be used as a consumer endpoint. Consumer endpoints can use Scheduled Poll Consumer Options to schedule endpoint invocation. By default consumer endpoints that return an array or collection will generate one exchange per element, and their routes will be executed once for each exchange. This behavior can be disabled by setting the endpoint property splitResult=false.

Message Headers

Any URI option can be provided in a message header for producer endpoints with a CamelOlingo4. prefix.

Message Body

All result message bodies utilize objects provided by the underlying Apache Olingo 4.0 API used by the Olingo4Component. Producer endpoints can specify the option name for incoming message body in the inBody endpoint URI parameter. For endpoints that return an array or collection, a consumer endpoint will map every element to distinct messages, unless splitResult is set to false.

Use cases

The following route reads top 5 entries from the People entity ordered by ascending FirstName property.

from("direct:...")
    .setHeader("CamelOlingo4.$top", "5");
    .to("olingo4://read/People?orderBy=FirstName%20asc");

The following route reads Airports entity using the key property value in incoming id header.

from("direct:...")
    .setHeader("CamelOlingo4.keyPredicate", header("id"))
    .to("olingo4://read/Airports");

The following route creates People entity using the ClientEntity in body message.

from("direct:...")
    .to("olingo4://create/People");

The following route calls an odata action using the ClientEntity in the body message. The body message may be null for actions that don’t expect an input.

from("direct:...")
    .to("olingo4://action/People");