org.apache.flink.runtime.rest.handler.router.RouterHandler Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flink.runtime.rest.handler.router;
import org.apache.flink.runtime.rest.handler.AbstractRestHandler;
import org.apache.flink.runtime.rest.handler.util.HandlerUtils;
import org.apache.flink.runtime.rest.messages.ErrorResponseBody;
import org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler;
import org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext;
import org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandler;
import org.apache.flink.shaded.netty4.io.netty.channel.ChannelPipeline;
import org.apache.flink.shaded.netty4.io.netty.channel.SimpleChannelInboundHandler;
import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.DefaultFullHttpResponse;
import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpHeaders;
import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpMethod;
import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpRequest;
import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponseStatus;
import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpVersion;
import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.QueryStringDecoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.Map;
import static java.util.Objects.requireNonNull;
/**
* Inbound handler that converts HttpRequest to Routed and passes Routed to the matched handler.
*
* This class replaces the standard error response to be identical with those sent by the {@link AbstractRestHandler}.
*
*
This class is based on:
* https://github.com/sinetja/netty-router/blob/1.10/src/main/java/io/netty/handler/codec/http/router/AbstractHandler.java
* https://github.com/sinetja/netty-router/blob/1.10/src/main/java/io/netty/handler/codec/http/router/Handler.java
*/
public class RouterHandler extends SimpleChannelInboundHandler {
private static final String ROUTER_HANDLER_NAME = RouterHandler.class.getName() + "_ROUTER_HANDLER";
private static final String ROUTED_HANDLER_NAME = RouterHandler.class.getName() + "_ROUTED_HANDLER";
private static final Logger LOG = LoggerFactory.getLogger(RouterHandler.class);
private final Map responseHeaders;
private final Router router;
public RouterHandler(Router router, final Map responseHeaders) {
this.router = requireNonNull(router);
this.responseHeaders = requireNonNull(responseHeaders);
}
public String getName() {
return ROUTER_HANDLER_NAME;
}
@Override
protected void channelRead0(ChannelHandlerContext channelHandlerContext, HttpRequest httpRequest) {
if (HttpHeaders.is100ContinueExpected(httpRequest)) {
channelHandlerContext.writeAndFlush(new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.CONTINUE));
return;
}
// Route
HttpMethod method = httpRequest.getMethod();
QueryStringDecoder qsd = new QueryStringDecoder(httpRequest.uri());
RouteResult routeResult = router.route(method, qsd.path(), qsd.parameters());
if (routeResult == null) {
respondNotFound(channelHandlerContext, httpRequest);
return;
}
routed(channelHandlerContext, routeResult, httpRequest);
}
private void routed(
ChannelHandlerContext channelHandlerContext,
RouteResult routeResult,
HttpRequest httpRequest) {
ChannelInboundHandler handler = (ChannelInboundHandler) routeResult.target();
// The handler may have been added (keep alive)
ChannelPipeline pipeline = channelHandlerContext.pipeline();
ChannelHandler addedHandler = pipeline.get(ROUTED_HANDLER_NAME);
if (handler != addedHandler) {
if (addedHandler == null) {
pipeline.addAfter(ROUTER_HANDLER_NAME, ROUTED_HANDLER_NAME, handler);
} else {
pipeline.replace(addedHandler, ROUTED_HANDLER_NAME, handler);
}
}
RoutedRequest request = new RoutedRequest<>(routeResult, httpRequest);
channelHandlerContext.fireChannelRead(request.retain());
}
private void respondNotFound(ChannelHandlerContext channelHandlerContext, HttpRequest request) {
LOG.trace("Request could not be routed to any handler. Uri:{} Method:{}", request.getUri(), request.getMethod());
HandlerUtils.sendErrorResponse(
channelHandlerContext,
request,
new ErrorResponseBody("Not found."),
HttpResponseStatus.NOT_FOUND,
responseHeaders);
}
}