[[olingo4-component]]
= Olingo4 Component

*Since Camel 2.19*

// HEADER START
*Both producer and consumer is supported*
// HEADER END

The Olingo4 component utilizes http://olingo.apache.org/[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 
http://www.odata.org/ecosystem/[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:

[source,java]
----------------------------------------------
    <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

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

== Olingo4 Options




// component options: START
The Olingo4 component supports 5 options, which are listed below.



[width="100%",cols="2,5,^1,2",options="header"]
|===
| Name | Description | Default | Type
| *configuration* (common) | To use the shared configuration |  | Olingo4Configuration
| *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
| *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 component should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities | false | boolean
| *useGlobalSslContextParameters* (security) | Enable usage of global SSL context parameters. | false | boolean
|===
// component options: END






// endpoint options: START
The Olingo4 endpoint is configured using URI syntax:

----
olingo4:apiName/methodName
----

with the following path and query parameters:

=== Path Parameters (2 parameters):


[width="100%",cols="2,5,^1,2",options="header"]
|===
| Name | Description | Default | Type
| *apiName* | *Required* What kind of operation to perform. The value can be one of: DEFAULT |  | Olingo4ApiName
| *methodName* | *Required* What sub operation to use for the selected operation |  | String
|===


=== Query Parameters (34 parameters):


[width="100%",cols="2,5,^1,2",options="header"]
|===
| 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. The value can be one of: InOnly, InOut, InOptionalOut |  | 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. |  | PollingConsumerPollStrategy
| *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
| *repeatCount* (scheduler) | Specifies a maximum limit of number of fires. So if you set it to 1, the scheduler will only fire once. If you set it to 5, it will only fire five times. A value of zero or negative means fire forever. | 0 | 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. The value can be one of: TRACE, DEBUG, INFO, WARN, ERROR, OFF | 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. |  | ScheduledExecutorService
| *scheduler* (scheduler) | To use a cron scheduler from either camel-spring or camel-quartz component. The value can be one of: none, spring, quartz | 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. The value can be one of: NANOSECONDS, MICROSECONDS, MILLISECONDS, SECONDS, MINUTES, HOURS, DAYS | MILLISECONDS | TimeUnit
| *useFixedDelay* (scheduler) | Controls if fixed delay or fixed rate is used. See ScheduledExecutorService in JDK for details. | true | boolean
|===
// endpoint options: END

== 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'_. 

[width="100%",cols="10%,10%,10%,70%",options="header",]
|=======================================================================
|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. 

[width="100%",cols="10%,10%,80%",options="header",]
|=======================================================================
|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 http://camel.apache.org/polling-consumer.html#PollingConsumer-ScheduledPollConsumerOptions[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
http://olingo.apache.org/javadoc/odata4/index.html[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. 

 

[source,java]
------------------------------------------------------------
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. 

 

[source,java]
------------------------------------------------------------
from("direct:...")
    .setHeader("CamelOlingo4.keyPredicate", header("id"))
    .to("olingo4://read/Airports");
------------------------------------------------------------

 

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

 

[source,java]
------------------------------------------------------------
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.



[source,java]
------------------------------------------------------------
from("direct:...")
    .to("olingo4://action/People");
------------------------------------------------------------

include::camel-spring-boot::page$olingo4-starter.adoc[]

