org.apache.flink.runtime.rest.handler

Class AbstractRestHandler<T extends RestfulGateway,R extends RequestBody,P extends ResponseBody,M extends MessageParameters>

java.lang.Object

org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerAdapter

org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandlerAdapter

org.apache.flink.shaded.netty4.io.netty.channel.SimpleChannelInboundHandler<RoutedRequest>

org.apache.flink.runtime.rest.handler.LeaderRetrievalHandler<T>

org.apache.flink.runtime.rest.handler.AbstractHandler<T,R,M>

org.apache.flink.runtime.rest.handler.AbstractRestHandler<T,R,P,M>

Type Parameters:

R - type of incoming requests

P - type of outgoing responses

All Implemented Interfaces:

AutoCloseable, org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler, org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandler, org.apache.flink.util.AutoCloseableAsync

Direct Known Subclasses:

AbstractAggregatingMetricsHandler, AbstractAsynchronousOperationHandlers.StatusHandler, AbstractAsynchronousOperationHandlers.TriggerHandler, AbstractExecutionGraphHandler, AbstractMetricsHandler, AbstractResourceManagerHandler, ClientCoordinationHandler, ClusterConfigHandler, ClusterOverviewHandler, DashboardConfigHandler, JobCancellationHandler, JobExecutionResultHandler, JobIdsHandler, JobManagerLogListHandler, JobsOverviewHandler, JobSubmitHandler, JobVertexBackPressureHandler, ShutdownHandler

@ChannelHandler.Sharable
public abstract class AbstractRestHandler<T extends RestfulGateway,R extends RequestBody,P extends ResponseBody,M extends MessageParameters>
extends AbstractHandler<T,R,M>

Super class for netty-based handlers that work with RequestBodys and ResponseBodys.

Subclasses must be thread-safe.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler

org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler.Sharable

Field Summary

Fields inherited from class org.apache.flink.runtime.rest.handler.AbstractHandler

log, MAPPER

Fields inherited from class org.apache.flink.runtime.rest.handler.LeaderRetrievalHandler

leaderRetriever, logger, responseHeaders, timeout

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractRestHandler(GatewayRetriever<? extends T> leaderRetriever, org.apache.flink.api.common.time.Time timeout, Map<String,String> responseHeaders, MessageHeaders<R,P,M> messageHeaders)

Method Summary

Modifier and Type	Method and Description
MessageHeaders<R,P,M>	getMessageHeaders()
protected abstract CompletableFuture<P>	handleRequest(HandlerRequest<R,M> request, T gateway) This method is called for every incoming request and returns a CompletableFuture containing a the response.
protected CompletableFuture<Void>	respondToRequest(org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext ctx, org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpRequest httpRequest, HandlerRequest<R,M> handlerRequest, T gateway) Respond to the given HandlerRequest.

Methods inherited from class org.apache.flink.runtime.rest.handler.AbstractHandler

closeAsync, closeHandlerAsync, respondAsLeader

Methods inherited from class org.apache.flink.runtime.rest.handler.LeaderRetrievalHandler

channelRead0

Methods inherited from class org.apache.flink.shaded.netty4.io.netty.channel.SimpleChannelInboundHandler

acceptInboundMessage, channelRead

Methods inherited from class org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandlerAdapter

channelActive, channelInactive, channelReadComplete, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught, userEventTriggered

Methods inherited from class org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, handlerAdded, handlerRemoved, isSharable

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.util.AutoCloseableAsync

close

Methods inherited from interface org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler

handlerAdded, handlerRemoved

Constructor Detail

AbstractRestHandler

protected AbstractRestHandler(GatewayRetriever<? extends T> leaderRetriever,
                              org.apache.flink.api.common.time.Time timeout,
                              Map<String,String> responseHeaders,
                              MessageHeaders<R,P,M> messageHeaders)

Method Detail

getMessageHeaders

public MessageHeaders<R,P,M> getMessageHeaders()

respondToRequest

protected CompletableFuture<Void> respondToRequest(org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext ctx,
                                                   org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpRequest httpRequest,
                                                   HandlerRequest<R,M> handlerRequest,
                                                   T gateway)

Description copied from class: AbstractHandler

Respond to the given HandlerRequest.

Specified by:

respondToRequest in class AbstractHandler<T extends RestfulGateway,R extends RequestBody,M extends MessageParameters>

Parameters:

ctx - channel handler context to write the response

httpRequest - original http request

handlerRequest - typed handler request

gateway - leader gateway

Returns:

Future which is completed once the request has been processed

handleRequest

protected abstract CompletableFuture<P> handleRequest(@Nonnull
                                                      HandlerRequest<R,M> request,
                                                      @Nonnull
                                                      T gateway)
                                               throws RestHandlerException

This method is called for every incoming request and returns a CompletableFuture containing a the response.

Implementations may decide whether to throw RestHandlerExceptions or fail the returned CompletableFuture with a RestHandlerException.

Failing the future with another exception type or throwing unchecked exceptions is regarded as an implementation error as it does not allow us to provide a meaningful HTTP status code. In this case a HttpResponseStatus.INTERNAL_SERVER_ERROR will be returned.

Parameters:

request - request that should be handled

gateway - leader gateway

Returns:

future containing a handler response

Throws:

RestHandlerException - if the handling failed