public interface Service
Starting with version 2.3.0, RPC implementations should not try to build on this, but should instead provide code generator plugins which generate code specific to the particular RPC implementation. This way the generated code can be more appropriate for the implementation in use and can avoid unnecessary layers of indirection.
Modifier and Type | Method and Description |
---|---|
void |
callMethod(Descriptors.MethodDescriptor method,
RpcController controller,
Message request,
RpcCallback<Message> done)
Call a method of the service specified by MethodDescriptor.
|
Descriptors.ServiceDescriptor |
getDescriptorForType()
Get the
ServiceDescriptor describing this service and its methods. |
Message |
getRequestPrototype(Descriptors.MethodDescriptor method)
callMethod() requires that the request passed in is of a particular subclass of Message . |
Message |
getResponsePrototype(Descriptors.MethodDescriptor method)
Like
getRequestPrototype() , but gets a prototype of the response message. |
Descriptors.ServiceDescriptor getDescriptorForType()
ServiceDescriptor
describing this service and its methods.void callMethod(Descriptors.MethodDescriptor method, RpcController controller, Message request, RpcCallback<Message> done)
switch()
that calls the standard definitions of the service's methods.
Preconditions:
method.getService() == getDescriptorForType()
request
is of the exact same class as the object returned by getRequestPrototype(method)
.
controller
is of the correct type for the RPC implementation being used by this
Service. For stubs, the "correct type" depends on the RpcChannel which the stub is using.
Server-side Service implementations are expected to accept whatever type of RpcController
the server-side RPC implementation uses.
Postconditions:
done
will be called when the method is complete. This may be before callMethod()
returns or it may be at some point in the future.
done
is the response. It must be of the exact same type as would
be returned by getResponsePrototype(method)
.
done
will be null
. Further details
about the failure can be found by querying controller
.
Message getRequestPrototype(Descriptors.MethodDescriptor method)
callMethod()
requires that the request passed in is of a particular subclass of Message
. getRequestPrototype()
gets the default instances of this type for a given
method. You can then call Message.newBuilderForType()
on this instance to construct a
builder to build an object which you can then pass to callMethod()
.
Example:
MethodDescriptor method = service.getDescriptorForType().findMethodByName("Foo"); Message request = stub.getRequestPrototype(method).newBuilderForType() .mergeFrom(input).build(); service.callMethod(method, request, callback);
Message getResponsePrototype(Descriptors.MethodDescriptor method)
getRequestPrototype()
, but gets a prototype of the response message. getResponsePrototype()
is generally not needed because the Service
implementation
constructs the response message itself, but it may be useful in some cases to know ahead of
time what type of object will be returned.Copyright © 2008–2022. All rights reserved.