与 helloworld 大致相同，不同的是 proto 定义修改了返回值，Client 端的返回值发生了变化， Server 端的发送变成了多个
service HelloService{
- rpc SayHello(HelloMessage) returns (HelloResponse){
+ rpc SayHello(HelloMessage) returns (stream HelloResponse){
}
}- 服务实现
@Slf4j
class HelloServiceImpl extends HelloServiceGrpc.HelloServiceImplBase {
@Override
public void sayHello(HelloMessage request, StreamObserver<HelloResponse> responseObserver) {
log.info("收到客户端请求: " + request.getMessage());
+ AtomicInteger counter = new AtomicInteger();
+ while (counter.get() < 100) {
// 构建响应
HelloResponse response = HelloResponse.newBuilder()
.setMessage(counter.get() + ": Hello " + request.getMessage())
.build();
// 发送响应
responseObserver.onNext(response);
+ counter.getAndIncrement();
}
responseObserver.onCompleted();
}
}使用 BlockingStub 发起请求，这个调用是同步的，返回值由 HelloResponse变成了Iterator<HelloResponse>
@Slf4j
public class HelloWorldClient {
public static void main(String[] args) throws InterruptedException {
ManagedChannel channel = ManagedChannelBuilder.forAddress("127.0.0.1", 9090)
.usePlaintext()
.build();
// 这里用 FutureStub 或者 AsyncStub 也是类似的，返回值变成 Future 或者传入 StreamObserver 即可
HelloServiceGrpc.HelloServiceBlockingStub blockingStub = HelloServiceGrpc.newBlockingStub(channel);
HelloMessage message = HelloMessage.newBuilder()
.setMessage("Blocking Stub")
.build();
- HelloResponse helloResponse = blockingStub.sayHello(message);
// 发送消息，并返回响应
+ Iterator<HelloResponse> helloResponses = blockingStub.sayHello(message);
+ while (helloResponses.hasNext()) {
log.info(helloResponses.next().getMessage());
+ }
channel.awaitTermination(5, TimeUnit.SECONDS);
}
}