A message endpoint is the interface between an application and a messaging system. As shown in Figure 9, you can have a sender endpoint, sometimes called a proxy or a service consumer, which is responsible for sending In messages, and a receiver endpoint, sometimes called an endpoint or a service, which is responsible for receiving In messages.
Apache Camel defines two basic types of endpoint:
Consumer endpoint — Appears at the start of a Apache Camel route and reads In messages from an incoming channel (equivalent to a receiver endpoint).
Producer endpoint — Appears at the end of a Apache Camel route and writes In messages to an outgoing channel (equivalent to a sender endpoint). It is possible to define a route with multiple producer endpoints.
In Apache Camel, an endpoint is represented by an endpoint URI, which typically encapsulates the following kinds of data:
Endpoint URI for a consumer endpoint — Advertises a specific location (for example, to expose a service to which senders can connect). Alternatively, the URI can specify a message source, such as a message queue. The endpoint URI can include settings to configure the endpoint.
Endpoint URI for a producer endpoint — Contains details of where to send messages and includes the settings to configure the endpoint. In some cases, the URI specifies the location of a remote receiver endpoint; in other cases, the destination can have an abstract form, such as a queue name.
An endpoint URI in Apache Camel has the following general form:
ComponentPrefix:ComponentSpecificURI
Where ComponentPrefix is a URI
prefix that identifies a particular Apache Camel component (see
???? for details of all the
supported components). The remaining part of the URI,
ComponentSpecificURI, has a
syntax defined by the particular component. For example, to
connect to the JMS queue, Foo.Bar, you can define
an endpoint URI like the following:
jms:Foo.Bar
To define a route that connects the consumer endpoint,
file://local/router/messages/foo, directly to
the producer endpoint, jms:Foo.Bar, you can use the
following Java DSL fragment:
from("file://local/router/messages/foo").to("jms:Foo.Bar");Alternatively, you can define the same route in XML, as follows:
<camelContext id="CamelContextID" xmlns="http://camel.apache.org/schema/spring">
<route>
<from uri="file://local/router/messages/foo"/>
<to uri="jms:Foo.Bar"/>
</route>
</camelContext> |  |  |
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