/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed 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
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package org.springframework.http.server.reactive;

import java.util.LinkedHashMap;
import java.util.Map;

import reactor.core.publisher.Mono;

import org.springframework.http.HttpStatus;
import org.springframework.util.Assert;

HttpHandler delegating requests to one of several HttpHandler's based on simple, prefix-based mappings.

This is intended as a coarse-grained mechanism for delegating requests to one of several applications -- each represented by an HttpHandler, with the application "context path" (the prefix-based mapping) exposed via ServerHttpRequest.getPath().

Author:Rossen Stoyanchev
Since:5.0
/** * {@code HttpHandler} delegating requests to one of several {@code HttpHandler}'s * based on simple, prefix-based mappings. * * <p>This is intended as a coarse-grained mechanism for delegating requests to * one of several applications -- each represented by an {@code HttpHandler}, with * the application "context path" (the prefix-based mapping) exposed via * {@link ServerHttpRequest#getPath()}. * * @author Rossen Stoyanchev * @since 5.0 */
public class ContextPathCompositeHandler implements HttpHandler { private final Map<String, HttpHandler> handlerMap; public ContextPathCompositeHandler(Map<String, ? extends HttpHandler> handlerMap) { Assert.notEmpty(handlerMap, "Handler map must not be empty"); this.handlerMap = initHandlers(handlerMap); } private static Map<String, HttpHandler> initHandlers(Map<String, ? extends HttpHandler> map) { map.keySet().forEach(ContextPathCompositeHandler::assertValidContextPath); return new LinkedHashMap<>(map); } private static void assertValidContextPath(String contextPath) { Assert.hasText(contextPath, "Context path must not be empty"); if (contextPath.equals("/")) { return; } Assert.isTrue(contextPath.startsWith("/"), "Context path must begin with '/'"); Assert.isTrue(!contextPath.endsWith("/"), "Context path must not end with '/'"); } @Override public Mono<Void> handle(ServerHttpRequest request, ServerHttpResponse response) { // Remove underlying context path first (e.g. Servlet container) String path = request.getPath().pathWithinApplication().value(); return this.handlerMap.entrySet().stream() .filter(entry -> path.startsWith(entry.getKey())) .findFirst() .map(entry -> { String contextPath = request.getPath().contextPath().value() + entry.getKey(); ServerHttpRequest newRequest = request.mutate().contextPath(contextPath).build(); return entry.getValue().handle(newRequest, response); }) .orElseGet(() -> { response.setStatusCode(HttpStatus.NOT_FOUND); return response.setComplete(); }); } }