io.grpc.stub

Class MetadataUtils

java.lang.Object

io.grpc.stub.MetadataUtils

public class MetadataUtils
extends Object

Utility functions for binding and receiving headers.

Method Summary

Modifier and Type	Method and Description
static <T extends AbstractStub<T>> T	attachHeaders(T stub, Metadata extraHeaders) Attaches a set of request headers to a stub.
static <T extends AbstractStub<T>> T	captureMetadata(T stub, AtomicReference<Metadata> headersCapture, AtomicReference<Metadata> trailersCapture) Captures the last received metadata for a stub.
static ClientInterceptor	newAttachHeadersInterceptor(Metadata extraHeaders) Returns a client interceptor that attaches a set of headers to requests.
static ClientInterceptor	newCaptureMetadataInterceptor(AtomicReference<Metadata> headersCapture, AtomicReference<Metadata> trailersCapture) Captures the last received metadata on a channel.

Methods inherited from class java.lang.Object

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

Method Detail

attachHeaders

@ExperimentalApi(value="https://github.com/grpc/grpc-java/issues/1789")
public static <T extends AbstractStub<T>> T attachHeaders(T stub,
                                                                                                                                  Metadata extraHeaders)

Attaches a set of request headers to a stub.

Parameters:

stub - to bind the headers to.

extraHeaders - the headers to be passed by each call on the returned stub.

Returns:

an implementation of the stub with extraHeaders bound to each call.

newAttachHeadersInterceptor

public static ClientInterceptor newAttachHeadersInterceptor(Metadata extraHeaders)

Returns a client interceptor that attaches a set of headers to requests.

Parameters:

extraHeaders - the headers to be passed by each call that is processed by the returned interceptor

captureMetadata

@ExperimentalApi(value="https://github.com/grpc/grpc-java/issues/1789")
public static <T extends AbstractStub<T>> T captureMetadata(T stub,
                                                                                                                                    AtomicReference<Metadata> headersCapture,
                                                                                                                                    AtomicReference<Metadata> trailersCapture)

Captures the last received metadata for a stub. Useful for testing

Parameters:

stub - to capture for

headersCapture - to record the last received headers

trailersCapture - to record the last received trailers

Returns:

an implementation of the stub that allows to access the last received call's headers and trailers via headersCapture and trailersCapture.

newCaptureMetadataInterceptor

public static ClientInterceptor newCaptureMetadataInterceptor(AtomicReference<Metadata> headersCapture,
                                                              AtomicReference<Metadata> trailersCapture)

Captures the last received metadata on a channel. Useful for testing.

Parameters:

headersCapture - to record the last received headers

trailersCapture - to record the last received trailers

Returns:

an implementation of the channel with captures installed.