Chapter 246. 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>246.1. URI format
olingo4://endpoint/<resource-path>?[options]
246.2. 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 |
| resolveProperty Placeholders (advanced) | Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. | true | boolean |
The Olingo4 endpoint is configured using URI syntax:
olingo4:apiName/methodName
with the following path and query parameters:
246.2.1. 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 |
246.2.2. Query Parameters (14 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 |
| 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 |
| 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 | |
| synchronous (advanced) | Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). | false | boolean |
246.3. Spring Boot Auto-Configuration
The component supports 14 options, which are listed below.
| Name | Description | Default | Type |
|---|---|---|---|
| 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.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.ssl-context-parameters | To configure security using SSLContextParameters | SSLContextParameters | |
| camel.component.olingo4.enabled | Enable olingo4 component | true | Boolean |
| camel.component.olingo4.resolve-property-placeholders | Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. | true | Boolean |
| camel.component.olingo4.use-global-ssl-context-parameters | Enable usage of global SSL context parameters. | false | Boolean |
246.4. 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 |
246.5. Endpoint HTTP Headers (since Camel 2.20)
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>.
246.6. 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>/$count | java.lang.Long |
246.7. Consumer Endpoints
Only the read endpoint can be used as a consumer endpoint. Consumer endpoints can use Scheduled Poll Consumer Options with a consumer. prefix to schedule endpoint invocation. By default consumer endpoints that return an array or collection will generate one exchange per element, and their routes will be executed once for each exchange. This behavior can be disabled by setting the endpoint property consumer.splitResult=false.
246.8. Message Headers
Any URI option can be provided in a message header for producer endpoints with a CamelOlingo4. prefix.
246.9. Message Body
All result message bodies utilize objects provided by the underlying Apache Olingo 4.0 API used by the Olingo4Component. Producer endpoints can specify the option name for incoming message body in the inBody endpoint URI parameter. For endpoints that return an array or collection, a consumer endpoint will map every element to distinct messages, unless consumer.splitResult is set to false.
246.10. Use cases
The following route reads top 5 entries from the People entity ordered by ascending FirstName property.
from("direct:...")
.setHeader("CamelOlingo4.$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");