Java: Replace @type with more specific types

[igfoo]

No description provided.

[smowton]

Looks sensible; should we tighten the various uses of RefType or Element to refer to these in QL at the same time?

[igfoo]

I left the QL unchanged to minimise the chances of breaking code, but happy to change that too if that's the consensus.

[igfoo]

I've tightened the QL types I found; I didn't see any Elements that need to be changed, though?

[smowton]

Looks good -- the only Element I remembered was from hasName which is of course mashing a lot of different alternates together anyhow so doesn't need changing