Olingo4

Since Camel 2.19

Both producer and consumer are supported

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]

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 Olingo4 component supports 16 options, which are listed below.

Name Description Default Type

configuration (common)

To use the shared configuration.

Olingo4Configuration

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.

boolean

httpHeaders (common)

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

Map

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

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

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

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.

true

boolean

httpAsyncClientBuilder (advanced)

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 (advanced)

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

sslContextParameters (security)

To configure security using SSLContextParameters.

SSLContextParameters

useGlobalSslContextParameters (security)

Enable usage of global SSL context parameters.

boolean

Endpoint Options

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 (common)

Required What kind of operation to perform.

Enum values:

  • DEFAULT

Olingo4ApiName

methodName (common)

Required What sub operation to use for the selected operation.

String

Query Parameters (32 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.

boolean

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

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

sendEmptyMessageWhenIdle (consumer)

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

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 (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

pollStrategy (consumer (advanced))

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.

boolean

httpAsyncClientBuilder (advanced)

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 (advanced)

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

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.

500

long

greedy (scheduler)

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

boolean

initialDelay (scheduler)

Milliseconds before the first poll starts.

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.

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.

Enum values:

  • 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. Use value spring or quartz for built in scheduler.

none

Object

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.

Enum values:

  • 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

sslContextParameters (security)

To configure security using SSLContextParameters.

SSLContextParameters

API Parameters (1 APIs)

The @Olingo4 endpoint is an API based component and has additional parameters based on which API name and API method is used. The API name and API method is located in the endpoint URI as the apiName/methodName path parameters:

olingo4:apiName/methodName

There are 1 API names as listed in the table below:

API Name Type Description

DEFAULT

Both

Olingo4 Client Api Interface

Each API is documented in the following sections to come.

API: DEFAULT

Both producer and consumer are supported

The DEFAULT API is defined in the syntax as follows:

olingo4:DEFAULT/methodName?[parameters]

The 9 method(s) is listed in the table below, followed by detailed syntax for each method. (API methods can have a shorthand alias name which can be used in the syntax instead of the name)

Method Alias Description

action

Calls a OData action

batch

Executes a batch request

create

Creates a new OData resource

delete

Deletes an OData resource and invokes callback with org

merge

Patches/merges an OData resource using HTTP MERGE

patch

Patches/merges an OData resource using HTTP PATCH

read

Reads an OData resource and invokes callback with appropriate result

update

Updates an OData resource

uread

Reads an OData resource and invokes callback with the unparsed input stream

Method action

Signatures:

  • void action(org.apache.olingo.commons.api.edm.Edm edm, String resourcePath, java.util.Map<String, String> endpointHttpHeaders, Object data, org.apache.camel.component.olingo4.api.Olingo4ResponseHandler responseHandler);

The olingo4/action API method has the parameters listed in the table below:

Parameter Description Type

data

Action data

Object

edm

Service Edm

Edm

endpointHttpHeaders

HTTP Headers to add/override the component versions

Map

resourcePath

Resource path to action

String

responseHandler

Org.apache.olingo.client.api.domain.ClientEntity callback handler

Olingo4ResponseHandler

Method batch

Signatures:

  • void batch(org.apache.olingo.commons.api.edm.Edm edm, java.util.Map<String, String> endpointHttpHeaders, Object data, org.apache.camel.component.olingo4.api.Olingo4ResponseHandler<java.util.List<org.apache.camel.component.olingo4.api.batch.Olingo4BatchResponse>> responseHandler);

The olingo4/batch API method has the parameters listed in the table below:

Parameter Description Type

data

Ordered org.apache.camel.component.olingo4.api.batch.Olingo4BatchRequest list

Object

edm

Service Edm

Edm

endpointHttpHeaders

HTTP Headers to add/override the component versions

Map

responseHandler

Callback handler

Olingo4ResponseHandler

Method create

Signatures:

  • void create(org.apache.olingo.commons.api.edm.Edm edm, String resourcePath, java.util.Map<String, String> endpointHttpHeaders, Object data, org.apache.camel.component.olingo4.api.Olingo4ResponseHandler responseHandler);

The olingo4/create API method has the parameters listed in the table below:

Parameter Description Type

data

Request data

Object

edm

Service Edm

Edm

endpointHttpHeaders

HTTP Headers to add/override the component versions

Map

resourcePath

Resource path to create

String

responseHandler

Callback handler

Olingo4ResponseHandler

Method delete

Signatures:

  • void delete(String resourcePath, java.util.Map<String, String> endpointHttpHeaders, org.apache.camel.component.olingo4.api.Olingo4ResponseHandler<org.apache.olingo.commons.api.http.HttpStatusCode> responseHandler);

The olingo4/delete API method has the parameters listed in the table below:

Parameter Description Type

endpointHttpHeaders

HTTP Headers to add/override the component versions

Map

resourcePath

Resource path for Entry

String

responseHandler

Org.apache.olingo.commons.api.http.HttpStatusCode callback handler

Olingo4ResponseHandler

Method merge

Signatures:

  • void merge(org.apache.olingo.commons.api.edm.Edm edm, String resourcePath, java.util.Map<String, String> endpointHttpHeaders, Object data, org.apache.camel.component.olingo4.api.Olingo4ResponseHandler responseHandler);

The olingo4/merge API method has the parameters listed in the table below:

Parameter Description Type

data

Patch/merge data

Object

edm

Service Edm

Edm

endpointHttpHeaders

HTTP Headers to add/override the component versions

Map

resourcePath

Resource path to update

String

responseHandler

Org.apache.olingo.client.api.domain.ClientEntity callback handler

Olingo4ResponseHandler

Method patch

Signatures:

  • void patch(org.apache.olingo.commons.api.edm.Edm edm, String resourcePath, java.util.Map<String, String> endpointHttpHeaders, Object data, org.apache.camel.component.olingo4.api.Olingo4ResponseHandler responseHandler);

The olingo4/patch API method has the parameters listed in the table below:

Parameter Description Type

data

Patch/merge data

Object

edm

Service Edm

Edm

endpointHttpHeaders

HTTP Headers to add/override the component versions

Map

resourcePath

Resource path to update

String

responseHandler

Org.apache.olingo.client.api.domain.ClientEntity callback handler

Olingo4ResponseHandler

Method read

Signatures:

  • void read(org.apache.olingo.commons.api.edm.Edm edm, String resourcePath, java.util.Map<String, String> queryParams, java.util.Map<String, String> endpointHttpHeaders, org.apache.camel.component.olingo4.api.Olingo4ResponseHandler responseHandler);

The olingo4/read API method has the parameters listed in the table below:

Parameter Description Type

edm

Service Edm, read from calling read(null, $metdata, null, responseHandler)

Edm

endpointHttpHeaders

HTTP Headers to add/override the component versions

Map

queryParams

Map

resourcePath

OData Resource path

String

responseHandler

Callback handler

Olingo4ResponseHandler

Method update

Signatures:

  • void update(org.apache.olingo.commons.api.edm.Edm edm, String resourcePath, java.util.Map<String, String> endpointHttpHeaders, Object data, org.apache.camel.component.olingo4.api.Olingo4ResponseHandler responseHandler);

The olingo4/update API method has the parameters listed in the table below:

Parameter Description Type

data

Updated data

Object

edm

Service Edm

Edm

endpointHttpHeaders

HTTP Headers to add/override the component versions

Map

resourcePath

Resource path to update

String

responseHandler

Org.apache.olingo.client.api.domain.ClientEntity callback handler

Olingo4ResponseHandler

Method uread

Signatures:

  • void uread(org.apache.olingo.commons.api.edm.Edm edm, String resourcePath, java.util.Map<String, String> queryParams, java.util.Map<String, String> endpointHttpHeaders, org.apache.camel.component.olingo4.api.Olingo4ResponseHandler<java.io.InputStream> responseHandler);

The olingo4/uread API method has the parameters listed in the table below:

Parameter Description Type

edm

Service Edm, read from calling read(null, $metdata, null, responseHandler)

Edm

endpointHttpHeaders

HTTP Headers to add/override the component versions

Map

queryParams

Map

resourcePath

OData Resource path

String

responseHandler

Callback handler

Olingo4ResponseHandler

In addition to the parameters above, the olingo4 API can also use any of the Query Parameters (32 parameters).

Any of the parameters can be provided in either the endpoint URI, or dynamically in a message header. The message header name must be of the format CamelOlingo4.parameter. The inBody parameter overrides message header, i.e. the endpoint parameter inBody=myParameterNameHere would override a CamelOlingo4.myParameterNameHere header.

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

Samples

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");

Spring Boot Auto-Configuration

When using olingo4 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-olingo4-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 17 options, which are listed below.

Name Description Default Type

camel.component.olingo4.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.olingo4.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.olingo4.configuration

To use the shared configuration. The option is a org.apache.camel.component.olingo4.Olingo4Configuration type.

Olingo4Configuration

camel.component.olingo4.connect-timeout

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

30000

Integer

camel.component.olingo4.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.enabled

Whether to enable auto configuration of the olingo4 component. This is enabled by default.

Boolean

camel.component.olingo4.filter-already-seen

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

false

Boolean

camel.component.olingo4.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. The option is a org.apache.http.impl.nio.client.HttpAsyncClientBuilder type.

HttpAsyncClientBuilder

camel.component.olingo4.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. The option is a org.apache.http.impl.client.HttpClientBuilder type.

HttpClientBuilder

camel.component.olingo4.http-headers

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

Map

camel.component.olingo4.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

camel.component.olingo4.proxy

HTTP proxy server configuration. The option is a org.apache.http.HttpHost type.

HttpHost

camel.component.olingo4.service-uri

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

String

camel.component.olingo4.socket-timeout

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

30000

Integer

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

To configure security using SSLContextParameters. The option is a org.apache.camel.support.jsse.SSLContextParameters type.

SSLContextParameters

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

Enable usage of global SSL context parameters.

false

Boolean