io.grpc

Class CallCredentials

java.lang.Object

io.grpc.CallCredentials

Direct Known Subclasses:

CompositeCallCredentials

public abstract class CallCredentials
extends Object

Carries credential data that will be propagated to the server via request metadata for each RPC.

This is used by CallOptions.withCallCredentials(io.grpc.CallCredentials) and withCallCredentials() on the generated stub, for example:

 FooGrpc.FooStub stub = FooGrpc.newStub(channel);
 response = stub.withCallCredentials(creds).bar(request);
 

The contents and nature of this class (and whether it remains an abstract class) is experimental, in that it can change. However, we are guaranteeing stability for the name. That is, we are guaranteeing stability for code to be returned a reference and pass that reference to gRPC for usage. However, code may not call or implement the CallCredentials itself if it wishes to only use stable APIs.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CallCredentials.MetadataApplier The outlet of the produced headers.
static class	CallCredentials.RequestInfo The request-related information passed to CallCredentials.applyRequestMetadata().

Constructor Summary

Constructors

Constructor and Description
CallCredentials()

Method Summary

Modifier and Type	Method and Description
abstract void	applyRequestMetadata(CallCredentials.RequestInfo requestInfo, Executor appExecutor, CallCredentials.MetadataApplier applier) Pass the credential data to the given CallCredentials.MetadataApplier, which will propagate it to the request metadata.
abstract void	thisUsesUnstableApi() Should be a noop but never called; tries to make it clearer to implementors that they may break in the future.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CallCredentials

public CallCredentials()

Method Detail

applyRequestMetadata

public abstract void applyRequestMetadata(CallCredentials.RequestInfo requestInfo,
                                          Executor appExecutor,
                                          CallCredentials.MetadataApplier applier)

Pass the credential data to the given CallCredentials.MetadataApplier, which will propagate it to the request metadata.

It is called for each individual RPC, within the Context of the call, before the stream is about to be created on a transport. Implementations should not block in this method. If metadata is not immediately available, e.g., needs to be fetched from network, the implementation may give the applier to an asynchronous task which will eventually call the applier. The RPC proceeds only after the applier is called.

Parameters:

requestInfo - request-related information

appExecutor - The application thread-pool. It is provided to the implementation in case it needs to perform blocking operations.

applier - The outlet of the produced headers. It can be called either before or after this method returns.

thisUsesUnstableApi

@ExperimentalApi(value="https://github.com/grpc/grpc-java/issues/1914")
public abstract void thisUsesUnstableApi()

Should be a noop but never called; tries to make it clearer to implementors that they may break in the future.