Can I include Java constant value in AsciiDoctor document?

Question

For example, lets have a Java constant in some class

public class MyClass{
  public static final String ENDPOINT="http://example.com"
}

and lets try to describe that class in AsciiDoctor (corporate docs reasons)

==== My class

..... some descripton ..... 
It is exposed trough http://example.com

Now every time I change the endpoint, I have to update docs manually as well (IDE find-and-replace will do the trick obviously). Is there a way to include Java constant into the AsciiDoc so I don't have to copy its value into the docs?

I would gladly see something like {import my.package.MyClass#ENDPOINT} or something similiar.

Answer 1

I'd write a shell script (PERL, whatever) that greps your Java code for a regex something like 'class (\\w+).*ENDPOINT="([^"]+)' , sending the results to an include file ( .\\endpoints.adoc ) using ':\\1_endpoint: \\2' , thus:

:MyClass_endpoint: http://example.com
:MyOtherClass_endpoint: http://other.example.com

Then, at the top of your AsciiDoc file insert: include::[endpoints.adoc]

and then refer to {MyClass_endpoint} and {MyOtherClass_endpoint} in the body.

Then, simply run the script as part of your toolchain prior to calling AsciiDoctor.

Answer 2

One other solution is to use the include-pattern of asciidoctor which is described here. https://docs.asciidoctor.org/asciidoc/latest/directives/include-tagged-regions/

In short.

Define a tagged region:

public class MyClass{
  //tag::endpointdefinition[]
  public static final String ENDPOINT="http://example.com"
  //end::endpointdefinition[]
}

include it your document

[source,java]
----
include::pathYourFile.java[tag=endpointdefinition] 
----

To optimize it a little bit you could break your lines different int the java file and place the tag definition on that. You could also remove the source around including the java file.