Android grpc java 传输文件demo

下面是一个简单的 Android gRPC Java 传输文件的演示，其中包括客户端和服务器端的代码。

1. 客户端代码

public class FileTransferClient {
    private ManagedChannel channel;
    private FileTransferServiceGrpc.FileTransferServiceBlockingStub blockingStub;

    public FileTransferClient(String host, int port) {
        channel = ManagedChannelBuilder.forAddress(host, port)
                .usePlaintext()
                .build();
        blockingStub = FileTransferServiceGrpc.newBlockingStub(channel);
    }

    public void shutdown() throws InterruptedException {
        channel.shutdown().awaitTermination(5, TimeUnit.SECONDS);
    }

    public void uploadFile(File file) {
        try {
            FileInputStream inputStream = new FileInputStream(file);
            StreamObserver<FileChunk> responseObserver = blockingStub.uploadFile(new StreamObserver<UploadStatus>() {
                @Override
                public void onNext(UploadStatus value) {
                    Log.d("FileUpload", "Upload status: " + value.getStatus());
                }

                @Override
                public void onError(Throwable t) {
                    Log.e("FileUpload", "Upload error: " + t.getMessage());
                }

                @Override
                public void onCompleted() {
                    Log.d("FileUpload", "Upload completed");
                }
            });

            byte[] buffer = new byte[1024];
            int bytesRead;
            while ((bytesRead = inputStream.read(buffer)) != -1) {
                FileChunk fileChunk = FileChunk.newBuilder()
                        .setData(ByteString.copyFrom(buffer, 0, bytesRead))
                        .build();
                responseObserver.onNext(fileChunk);
            }

            responseObserver.onCompleted();
            inputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

2. 服务器端代码

public class FileTransferServer {
    private static final Logger logger = Logger.getLogger(FileTransferServer.class.getName());
    private Server server;

    public void start(int port) throws IOException {
        server = ServerBuilder.forPort(port)
                .addService(new FileTransferServiceImpl())
                .build()
                .start();
        logger.info("Server started, listening on " + port);
        Runtime.getRuntime().addShutdownHook(new Thread() {
            @Override
            public void run() {
                System.err.println("*** Shutting down gRPC server since JVM is shutting down");
                FileTransferServer.this.stop();
                System.err.println("*** Server shut down");
            }
        });
    }

    private void stop() {
        if (server != null) {
            server.shutdown();
        }
    }

    private void blockUntilShutdown() throws InterruptedException {
        if (server != null) {
            server.awaitTermination();
        }
    }

    public static void main(String[] args) throws IOException, InterruptedException {
        final FileTransferServer server = new FileTransferServer();
        server.start(50051);
        server.blockUntilShutdown();
    }

    static class FileTransferServiceImpl extends FileTransferServiceGrpc.FileTransferServiceImplBase {
        private FileOutputStream outputStream;

        @Override
        public StreamObserver<FileChunk> uploadFile(StreamObserver<UploadStatus> responseObserver) {
            outputStream = null;
            try {
                outputStream = new FileOutputStream("path_to_save_file"); // 修改为你想要保存文件的路径
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }

            return new StreamObserver<FileChunk>() {
                @Override
                public void onNext(FileChunk value) {
                    try {
                        outputStream.write(value.getData().toByteArray());
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }

                @Override
                public void onError(Throwable t) {
                    t.printStackTrace();
                }

                @Override
                public void onCompleted() {
                    try {
                        outputStream.flush();
                        outputStream.close();
                        UploadStatus uploadStatus = UploadStatus.newBuilder()
                                .setStatus("Success")
                                .build();
                        responseObserver.onNext(uploadStatus);
                        responseObserver.onCompleted();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            };
        }
    }
}

这个示例演示了如何使用 gRPC 在 Android 上上传文件。在客户端代码中，我们创建了一个 `FileTransferClient` 类，它包含了与服务器通信的代码。在服务器端代码中，我们创建了一个 `FileTransferServer` 类，它包含了接收上传文件的代码。文件被分成块，并逐个发送到服务器。在服务器端，每个块被写入文件，直到接收到所有的块。在客户端，我们会收到上传的状态，包括上传是否成功以及错误信息。