Provide literals for built-in annotations

[arjantijms]

Since CDI 2.0, CDI provides annotation literals for many of its annotations (see https://issues.jboss.org/browse/CDI-485).

Just as the built-in CDI annotations, EE Security annotation literals are also being implemented by projects. As a public example, see https://github.com/javaee-samples/javaee8-samples/blob/master/security/dynamic-rememberme/src/main/java/org/javaee8/security/dynamic/rememberme/util/RememberMeAnnotationLiteral.java

Literals are useful for looking up bean instances using the bean manager, as well as when applying interceptors dynamically.

[keilw]

Why a no-op of() method, wouldn't INSTANCE also work here?

An of() without any argument, see Optional is rather unusual in Java SE, or did CDI pick it up somewhere?

[arjantijms]

Why a no-op of() method, wouldn't INSTANCE also work here?

With INSTANCE you'd expect a constant. The CDI examples all use of() but with a parameter (since all these only have 1 annotation attribute).

There needs to be something to kickoff the builder. Open to suggestions in a followup PR.

[arjantijms]

P.s. an alternative I was playing with is:

RememberMe literal = RememberMe.Literal.of(
    cookieMaxAgeSeconds(100),
    cookieSecureOnly(false),
    cookieHttpOnly(false)
 );

Where cookieMaxAgeSeconds etc are statically imported methods that return a NamedParameter instance. The of() method is a varargs method exception these. It's roughly like how the Java SE 8 stream method collect() works.

It reads a bit nicer, but you'd have to import these methods, which may be a bit less self-discovery than chaining builders calls.

Thoughts?

[keilw]

I'll propose something along the lines of

RememberMe literal = RememberMe.Literal.builder()
                                       .cookieMaxAgeSeconds(100)
                                       .cookieSecureOnly(false)
                                       .cookieHttpOnly(false)
                                       .build();

As the method does not return Literal itself, but the LiteralBuilder. And look at Optional and all other cases I know, of(), valueOf() or instanceOf() always return the exact class they're applied on, and not a builder.