Chapter 63. CoAP Component

Available as of Camel version 2.16

Camel-CoAP is an Apache Camel component that allows you to work with CoAP, a lightweight REST-type protocol for machine-to-machine operation. CoAP, Constrained Application Protocol is a specialized web transfer protocol for use with constrained nodes and constrained networks and it is based on RFC 7252.

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

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

63.1. Options

The CoAP component has no options.

The CoAP endpoint is configured using URI syntax:

coap:uri

with the following path and query parameters:

63.1.1. Path Parameters (1 parameters):

NameDescriptionDefaultType

uri

The URI for the CoAP endpoint

 

URI

63.1.2. Query Parameters (5 parameters):

NameDescriptionDefaultType

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

coapMethodRestrict (consumer)

Comma separated list of methods that the CoAP consumer will bind to. The default is to bind to all methods (DELETE, GET, POST, PUT).

 

String

exceptionHandler (consumer)

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this options 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

63.2. Message Headers

NameTypeDescription

CamelCoapMethod

String

The request method that the CoAP producer should use when calling the target CoAP server URI. Valid options are DELETE, GET, PING, POST & PUT.

CamelCoapResponseCode

String

The CoAP response code sent by the external server. See RFC 7252 for details of what each code means.

CamelCoapUri

String

The URI of a CoAP server to call. Will override any existing URI configured directly on the endpoint.

63.2.1. Configuring the CoAP producer request method

The following rules determine which request method the CoAP producer will use to invoke the target URI:

  1. The value of the CamelCoapMethod header
  2. GET if a query string is provided on the target CoAP server URI.
  3. POST if the message exchange body is not null.
  4. GET otherwise.