抖音直播间数据采集，ProtoBuf + gRPC 分析请求头

短视频、直播数据实时采集接口，请查看文档： TiToData

免责声明：本文档仅供学习与参考，请勿用于非法用途！否则一切后果自负。

概念

Protobuf是Google protocol buffer的简称，是一种语言中立、平台无关、易于扩展的结构化数据序列化技术，可用于数据传输、存储等领域。
与Protoful类似的序列化技术还有XML、JSON、Thrift等，但Protoful更快、更小、更简单，且具备良好的兼容性。

目前经常运用在安卓直播弹幕等业务场景中

配置请求头

方法1

只设置客户端请求时附带的header

类 io.grpc.stub.MetadataUtils，其中有个方法

@ExperimentalApi("https://github.com/grpc/grpc-java/issues/1789")
  public static <T extends AbstractStub<T>> T attachHeaders(
      T stub,
      final Metadata extraHeaders) {
    return stub.withInterceptors(newAttachHeadersInterceptor(extraHeaders));
  }

**
自己封装后

private static <T extends AbstractStub<T>> T attachHeaders(T stub, final Map<String, String> headerMap) {
    Metadata extraHeaders = new Metadata();
    if (headerMap != null) {
        for (String key : headerMap.keySet()) {
            Metadata.Key<String> customHeadKey = Metadata.Key.of(key, Metadata.ASCII_STRING_MARSHALLER);
            extraHeaders.put(customHeadKey, headerMap.get(key));
        }
    }
    return MetadataUtils.attachHeaders(stub, extraHeaders);
}

方法2

支持设置客户端请求的header以及获取服务端返回结果中的header

1. 设置拦截器

class HeaderClientInterceptor implements ClientInterceptor {
    private static final String TAG = "HeaderClientInterceptor";
    private Map<String, String> mHeaderMap;
    public HeaderClientInterceptor(Map<String, String> headerMap) {
        mHeaderMap = headerMap;
    }
    @Override
    public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(MethodDescriptor<ReqT, RespT> method,
                                                               CallOptions callOptions, Channel next) {
        return new SimpleForwardingClientCall<ReqT, RespT>(next.newCall(method, callOptions)) {
            @Override
            public void start(Listener<RespT> responseListener, Metadata headers) {
                /* put custom header */
                if (mHeaderMap != null) {
                    for (String key : mHeaderMap.keySet()) {
                        Metadata.Key<String> customHeadKey = Metadata.Key.of(key, Metadata.ASCII_STRING_MARSHALLER);
                        headers.put(customHeadKey, mHeaderMap.get(key));
                    }
                }
                Logger.i(TAG, "header send to server:" + headers);
                super.start(new SimpleForwardingClientCallListener<RespT>(responseListener) {
                    @Override
                    public void onHeaders(Metadata headers) {
                        /**
                         * if you don't need receive header from server,
                         * you can use {@link io.grpc.stub.MetadataUtils attachHeaders}
                         * directly to send header
                         */
                        Logger.i(TAG, "header received from server:" + headers);
                        super.onHeaders(headers);
                    }
                }, headers);
            }
        };
    }
}

2. 使用

Map<String, String> headerMap = new HashMap<>();
//...
ClientInterceptor interceptor = new HeaderClientInterceptor(headerMap);
//...
ManagedChannel managedChannel = ManagedChannelBuilder.forAddress(host, port).usePlaintext(true).build();
Channel channel = ClientInterceptors.intercept(managedChannel, interceptor);
// then create stub here by this channel