Interface TransportChannelProvider

public interface TransportChannelProvider

Provides an interface to either build a TransportChannel or provide a fixed TransportChannel that will be used to make calls to a service.

Implementations of TransportChannelProvider may choose to create a new TransportChannel for each call to #getTransportChannel, or may return a fixed TransportChannel instance.

Callers should use the following pattern to get a channel:


 TransportChannelProvider transportChannelProvider = ...;
 if (transportChannelProvider.needsHeaders()) {
   transportChannelProvider = transportChannelProvider.withHeaders(headers);
 }
 // optional: set executor for TransportChannel
 transportChannelProvider.withExecutor(executor);
 TransportChannel transportChannel = transportChannelProvider.getTransportChannel();
 

Methods

acceptsPoolSize()

public abstract boolean acceptsPoolSize()

Reports whether this provider allows pool size customization.

Returns
TypeDescription
boolean

getTransportChannel()

public abstract TransportChannel getTransportChannel()

Provides a Transport, which could either be a new instance for every call, or the same instance, depending on the implementation.

If #needsExecutor() is true, then #withExecutor(Executor) needs to be called first to provide an executor.

If #needsHeaders() is true, then #withHeaders(Map) needs to be called first to provide headers.

if #needsEndpoint() is true, then #withEndpoint(String) needs to be called first to provide an endpoint.

Returns
TypeDescription
TransportChannel
Exceptions
TypeDescription
IOException

getTransportName()

public abstract String getTransportName()

The name of the transport.

This string can be used for identifying transports for switching logic.

Returns
TypeDescription
String

needsCredentials()

public abstract boolean needsCredentials()

True if credentials are needed before channel creation.

Returns
TypeDescription
boolean

needsEndpoint()

public abstract boolean needsEndpoint()

True if the TransportProvider has no endpoint set.

Returns
TypeDescription
boolean

needsExecutor() (deprecated)

public abstract boolean needsExecutor()

Deprecated. Channel providers will have default executors if they need one.

True if the TransportProvider needs an executor.

Returns
TypeDescription
boolean

needsHeaders()

public abstract boolean needsHeaders()

True if the TransportProvider has no headers provided.

Returns
TypeDescription
boolean

shouldAutoClose()

public abstract boolean shouldAutoClose()

Indicates whether the TransportChannel should be closed by the containing client class.

Returns
TypeDescription
boolean

withCredentials(Credentials credentials)

public abstract TransportChannelProvider withCredentials(Credentials credentials)

Sets the credentials that will be applied before channel creation.

Parameter
NameDescription
credentialscom.google.auth.Credentials
Returns
TypeDescription
TransportChannelProvider

withEndpoint(String endpoint)

public abstract TransportChannelProvider withEndpoint(String endpoint)

Sets the endpoint to use when constructing a new TransportChannel.

This method should only be called if #needsEndpoint() returns true.

Parameter
NameDescription
endpointString
Returns
TypeDescription
TransportChannelProvider

withExecutor(Executor executor)

public abstract TransportChannelProvider withExecutor(Executor executor)

Sets the executor to use when constructing a new TransportChannel.

Parameter
NameDescription
executorExecutor
Returns
TypeDescription
TransportChannelProvider

withExecutor(ScheduledExecutorService executor) (deprecated)

public abstract TransportChannelProvider withExecutor(ScheduledExecutorService executor)

Deprecated. Please use #withExecutor(Executor).

Parameter
NameDescription
executorScheduledExecutorService
Returns
TypeDescription
TransportChannelProvider

withHeaders(Map<String,String> headers)

public abstract TransportChannelProvider withHeaders(Map<String,String> headers)

Sets the headers to use when constructing a new TransportChannel.

This method should only be called if #needsHeaders() returns true.

Parameter
NameDescription
headersMap<String,String>
Returns
TypeDescription
TransportChannelProvider

withPoolSize(int size)

public abstract TransportChannelProvider withPoolSize(int size)

Number of underlying transport channels to open. Calls will be load balanced across them.

Parameter
NameDescription
sizeint
Returns
TypeDescription
TransportChannelProvider