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1 /*
2  * Copyright 2023 The gRPC Authors
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package io.grpc.examples.multiplex;
18 
19 import io.grpc.Grpc;
20 import io.grpc.InsecureServerCredentials;
21 import io.grpc.Server;
22 import io.grpc.ServerBuilder;
23 import io.grpc.StatusRuntimeException;
24 import io.grpc.examples.helloworld.GreeterGrpc;
25 import io.grpc.examples.helloworld.HelloReply;
26 import io.grpc.examples.helloworld.HelloRequest;
27 import io.grpc.examples.echo.EchoGrpc;
28 import io.grpc.examples.echo.EchoRequest;
29 import io.grpc.examples.echo.EchoResponse;
30 import io.grpc.stub.StreamObserver;
31 import java.io.IOException;
32 import java.util.concurrent.TimeUnit;
33 import java.util.logging.Logger;
34 
35 /**
36  * A sample gRPC server that serves both the Greeting and Echo services.
37  */
38 public class MultiplexingServer {
39 
40   private static final Logger logger = Logger.getLogger(MultiplexingServer.class.getName());
41 
42   private final int port;
43   private Server server;
44 
MultiplexingServer(int port)45   public MultiplexingServer(int port) throws IOException {
46     this.port = port;
47   }
48 
start()49   private void start() throws IOException {
50     /* The port on which the server should run */
51     server = Grpc.newServerBuilderForPort(port, InsecureServerCredentials.create())
52         .addService(new MultiplexingServer.GreeterImpl())
53         .addService(new EchoService())
54         .build()
55         .start();
56     logger.info("Server started, listening on " + port);
57     Runtime.getRuntime().addShutdownHook(new Thread() {
58       @Override
59       public void run() {
60         // Use stderr here since the logger may have been reset by its JVM shutdown hook.
61         System.err.println("*** shutting down gRPC server since JVM is shutting down");
62         try {
63           MultiplexingServer.this.stop();
64         } catch (InterruptedException e) {
65           e.printStackTrace(System.err);
66         }
67         System.err.println("*** server shut down");
68       }
69     });
70   }
71 
stop()72   private void stop() throws InterruptedException {
73     if (server != null) {
74       server.shutdown().awaitTermination(30, TimeUnit.SECONDS);
75     }
76   }
77 
78   /**
79    * Await termination on the main thread since the grpc library uses daemon threads.
80    */
blockUntilShutdown()81   private void blockUntilShutdown() throws InterruptedException {
82     if (server != null) {
83       server.awaitTermination();
84     }
85   }
86 
87   /**
88    * Main launches the server from the command line.
89    */
main(String[] args)90   public static void main(String[] args) throws IOException, InterruptedException {
91     System.setProperty("java.util.logging.SimpleFormatter.format",
92         "%1$tH:%1$tM:%1$tS %4$s %2$s: %5$s%6$s%n");
93 
94     final MultiplexingServer server = new MultiplexingServer(50051);
95     server.start();
96     server.blockUntilShutdown();
97   }
98 
99   static class GreeterImpl extends GreeterGrpc.GreeterImplBase {
100 
101     @Override
sayHello(HelloRequest req, StreamObserver<HelloReply> responseObserver)102     public void sayHello(HelloRequest req, StreamObserver<HelloReply> responseObserver) {
103       logger.info("Received sayHello request: " + req.getName());
104       HelloReply reply = HelloReply.newBuilder().setMessage("Hello " + req.getName()).build();
105       responseObserver.onNext(reply);
106       responseObserver.onCompleted();
107     }
108   }
109 }
110