* Build on JDK 8 and 17 as well as 11.
* Remove JDK 8 for now.
`DefaultDateTypeAdapterTest` fails.
* Tweak javadoc to avoid warnings.
Mostly these are about using `<h3>` when the previous tag was `<h1>`,
and the like. This previous tag might be implicit (part of what javadoc
itself outputs rather than the HTML in doc comments).
Apparently JDK 11 puts method javadoc inside `<h2>` while JDK 11 puts it
inside `<h3>`. Or something like that. Anyway it doesn't appear to be
possible to use `<h3>` _or_ `<h4>` and please both.
The most notable impact of this change is that it adds several new public APIs:
- The TypeAdapter abstract class
- The TypeAdapter.Factory interface
- Four new methods on GsonBuilder to register streaming TypeAdapters (via Factory, via Class, via TypeToken, and as a type hierarchy)
- Three new methods on Gson to lookup streaming TypeAdapters (by type, by class, and to get the next type adapter)
Still outstanding:
- Write beautiful prose to document the new APIs above
- Change GsonBuilder's precedence so that both old and new-style type adapters are registered in one lot
The most significant impact of this change is that fields whose types are type parameters should now GSONify just fine. For example, consider the class below.
abstract class Foo<A, B> {
A a;
B b;
List<A> list;
Map<A, List<B>> map;
}
class RealFoo extends Foo<String, Integer> {...}
This is a reasonable checkpoint but some work still needs to be done for this. In particular, the level of visibility of methods in TypeToken and Type should be reconsidered; we're exposing more than we need to!
