Introduce io.grpc.Uri.

[jdcormie]

io.grpc.Uri is an implementation of RFC 3986 tailored for grpc-java's needs. It lifts some of the limitations of java.net.URI that currently prevent us from resolving target URIs like intent:#Intent;... See #12244 for more.

Marked @Internal for now but the plan is to eventually use this to replace java.net.URI in our public APIs such as NameResolver.Factory.

[ejona86]

This looks nice. It's slightly strange you can't create a builder directly, but that'd just have you do Uri.create("myscheme:").toBuilder(), which seems pretty clear and guarantees there is a scheme.

[jdcormie]

This looks nice. It's slightly strange you can't create a builder directly, but that'd just have you do Uri.create("myscheme:").toBuilder(), which seems pretty clear and guarantees there is a scheme.

Thanks! Actually the Builder() ctor is public. My intention is for users to write code like:

Uri uri =
        new Uri.Builder()
            .setScheme("http")
            .setHost("grpc.io")
            .setPath("/index.html")
            .build();

Maybe there should be a public static newBuilder() method instead to match Attributes and CreateSubchannelArgs and MethodDescriptor ... ?

[ejona86]

Ah, I see. Yeah, it would match our other APIs more to have a newBuilder(). You should probably add a note to the API that creates a builder that scheme must be set before build().