InternalListener.java

/**
 * Since every interceptor needs to register as listener to next in chain, and on getting notified
 * should notify previous listener in the chain. This class will be the new listener which holds
 * reference to previous listener and gets registered to next interceptor in the chain.
 *
 * @param <ReqT> request msg of generic type ReqT.
 * @param <RespT> response msg of generic type RespT.
 * @param <T> methodInfo of generic type T.
 */
public class InternalListener<ReqT, RespT, T> extends UberNetworkListener<RespT> {

  private static final Logger LOGGER = Logger.getLogger(InternalListener.class.getName());

  public String identifier;
  @Nullable private UberCallListener<RespT> prevListener;
  @Nullable private UberInternalCallOptions callOptions;
  @Nullable private MethodInfo<T> methodInfo;
  private UberInterceptor<ReqT, RespT, T> interceptor;

  public InternalListener(
      String identifier,
      @Nullable UberInternalCallOptions callOptions,
      MethodInfo<T> methodInfo,
      @Nullable UberCallListener<RespT> prevListener,
      UberInterceptor<ReqT, RespT, T> interceptor) {
    super();
    this.identifier = identifier;
    this.callOptions = callOptions;
    this.methodInfo = methodInfo;
    this.prevListener = prevListener;
    this.interceptor = interceptor;
  }

  /** On response headers. */
  @Override
  public void onHeaders(UberCallHeaders headers) {
    interceptor.onResponseHeaders(headers);
    if (prevListener != null) {
      prevListener.onHeaders(headers);
    }
  }

  /** On response msg. */
  @Override
  public void onMessage(RespT message) {
    if (methodInfo != null) {
      interceptor.onResponseMsg(message);
      if (prevListener != null) {
        prevListener.onMessage(message);
      }
    }
  }

  /**
   * Invoked on closing a request. Refer
   * https://grpc.github.io/grpc-java/javadoc/io/grpc/ClientCall.Listener.html for more details.
   */
  @Override
  public void onClose(UberNetworkRequestStatus status, UberCallHeaders trailers) {
    interceptor.onComplete(status, trailers);
    if (prevListener != null) {
      prevListener.onClose(status, trailers);
    }
  }

  /**
   * Refer https://grpc.github.io/grpc-java/javadoc/io/grpc/ClientCall.Listener.html for more
   * details.
   */
  @Override
  public void onReady() {
    if (prevListener != null) {
      prevListener.onReady();
    }
  }
}