1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc. All rights reserved.
3 // http://code.google.com/p/protobuf/
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31 package com.google.protobuf;
34 * <p>Abstract interface for an RPC channel. An {@code RpcChannel} represents a
35 * communication line to a {@link Service} which can be used to call that
36 * {@link Service}'s methods. The {@link Service} may be running on another
37 * machine. Normally, you should not call an {@code RpcChannel} directly, but
38 * instead construct a stub {@link Service} wrapping it. Example:
41 * RpcChannel channel = rpcImpl.newChannel("remotehost.example.com:1234");
42 * RpcController controller = rpcImpl.newController();
43 * MyService service = MyService.newStub(channel);
44 * service.myMethod(controller, request, callback);
47 * <p>Starting with version 2.3.0, RPC implementations should not try to build
48 * on this, but should instead provide code generator plugins which generate
49 * code specific to the particular RPC implementation. This way the generated
50 * code can be more appropriate for the implementation in use and can avoid
51 * unnecessary layers of indirection.
53 * @author kenton@google.com Kenton Varda
55 public interface RpcChannel {
57 * Call the given method of the remote service. This method is similar to
58 * {@code Service.callMethod()} with one important difference: the caller
59 * decides the types of the {@code Message} objects, not the callee. The
60 * request may be of any type as long as
61 * {@code request.getDescriptor() == method.getInputType()}.
62 * The response passed to the callback will be of the same type as
63 * {@code responsePrototype} (which must have
64 * {@code getDescriptor() == method.getOutputType()}).
66 void callMethod(Descriptors.MethodDescriptor method,
67 RpcController controller,
69 Message responsePrototype,
70 RpcCallback<Message> done);