How should I name Apache Camel DSL elements? Are they "functions"? "Methods"? "Verbs"?

Question

When I want to refer to the elements used in creating a route in Apache Camel (like from , setBody , to , etc), what name should I use? Just call it a "function"? Can I call "method"? Or does it have a more specific and appropriate name?

I've seen people calling it "verb". Would that be an appropriate nomination too?

An example of route definition is:

from("rest:post:bin")
.removeHeader(Exchange.HTTP_URI)
.setHeader("CamelHttpMethod", constant("POST"))
.to("http://httpbin.org/anything")
.unmarshal().json(JsonLibrary.Gson)
.setBody(simple("${body[data]}"))

In this example we use the from , removeHeader , setHeader , to , unmarshal and setBody elements of the Java DSL.

I know that, programmatically, they are function and methods. But using code is not the only way to define a route. We can use these same elements to define a route using the XML or Yaml DSL , for example. So I imagine that simply calling "function" might not be the most appropriate option for naming these DSL elements.

Thanks!

Answer 1

Generally you should use terms defined in the Enterprise integration patterns book and website . This is what Camel documentation uses, what Camel in Action book uses and what are generally considered to be most universal terms when using camel whether you use xml-dsl, yaml-dsl or Java-dsl.

Camel Java-DSL uses something like Builder design pattern that uses method-chaining technique to define routes.

In Java-DSL when you call from("direct:example") method in your route-builder Camel creates new RouteDefition with direct:example Consumer-endpoint. The Method returns you the RouteDefinition object which you can then use to add Producer-endpoints and processors to that RouteDefinition generally using a pipeline .

Examples:

• from() -> Consumer endpoint
• to() -> Producer endpoint / Enricher
• removeHeader, setHeader, unmarshal and setBody -> Processors
• split() -> Spillter
• aggregate() -> Aggregator