Class BidiStream<RequestT,ResponseT> (2.18.0) 

public class BidiStream<RequestT,ResponseT> extends ServerStream<ResponseT> implements ClientStream<RequestT>

A wrapper around a bidirectional stream.

This class asynchronously pulls responses from upstream via StreamController#request(int) and exposes them via its Iterator. The implementation is back pressure aware and uses a constant buffer of 1 item.

Please note that the stream can only be consumed once and must either be fully consumed or be canceled.

This class can also be used to send requests to the server using #send(Object).

Neither this class nor the iterator it returns is thread-safe.

In the example below, we iterate through responses from the server and echo back the items we see:


 BidiStream<Item> stream = ...;

 for (Item item : stream) {
   System.out.println(item.id());

   stream.send(item.id());

   // Allow for early termination
   if (item.id().equals("needle")) {
     // Cancelling the stream will cause hasNext() to return false on the next iteration,
     // naturally breaking the loop.
     stream.cancel();
   }
 }

Inheritance

java.lang.Object > ServerStream > BidiStream<RequestT,ResponseT>

Implements

com.google.api.gax.rpc.ClientStream<RequestT>

Type Parameters

NameDescription
RequestT
ResponseT

Methods

closeSend()

public void closeSend()

Closes the sending side of the stream. Once called, no further calls to #send(Object), #closeSend(), or #closeSendWithError(Throwable) are allowed.

Calling this method does not affect the receiving side, the iterator will continue to yield responses from the server.

closeSendWithError(Throwable t)

public void closeSendWithError(Throwable t)

Closes the sending side of the stream with error. The error is propagated to the server. Once called, no further calls to #send(Object), #closeSend(), or #closeSendWithError(Throwable) are allowed.

Calling this method does not affect the receiving side, the iterator will continue to yield responses from the server.

Parameter
NameDescription
tThrowable

isSendReady()

public boolean isSendReady()

Reports whether a message can be sent without requiring excessive buffering internally.

This method only provides a hint. It is still correct for the user to call #send(Object) even when this method returns false.

Returns
TypeDescription
boolean

send(RequestT req)

public void send(RequestT req)

Send req to the server.

Parameter
NameDescription
reqRequestT