001/* 002 * Copyright 2002-2020 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.web.server.handler; 018 019import java.util.ArrayList; 020import java.util.Collections; 021import java.util.List; 022 023import reactor.core.publisher.Mono; 024 025import org.springframework.http.HttpMethod; 026import org.springframework.http.server.reactive.ServerHttpRequest; 027import org.springframework.util.StringUtils; 028import org.springframework.web.server.ServerWebExchange; 029import org.springframework.web.server.WebExceptionHandler; 030import org.springframework.web.server.WebHandler; 031 032/** 033 * WebHandler decorator that invokes one or more {@link WebExceptionHandler WebExceptionHandlers} 034 * after the delegate {@link WebHandler}. 035 * 036 * @author Rossen Stoyanchev 037 * @since 5.0 038 */ 039public class ExceptionHandlingWebHandler extends WebHandlerDecorator { 040 041 private final List<WebExceptionHandler> exceptionHandlers; 042 043 044 /** 045 * Create an {@code ExceptionHandlingWebHandler} for the given delegate. 046 * @param delegate the WebHandler delegate 047 * @param handlers the WebExceptionHandlers to apply 048 */ 049 public ExceptionHandlingWebHandler(WebHandler delegate, List<WebExceptionHandler> handlers) { 050 super(delegate); 051 List<WebExceptionHandler> handlersToUse = new ArrayList<>(); 052 handlersToUse.add(new CheckpointInsertingHandler()); 053 handlersToUse.addAll(handlers); 054 this.exceptionHandlers = Collections.unmodifiableList(handlersToUse); 055 } 056 057 058 /** 059 * Return a read-only list of the configured exception handlers. 060 */ 061 public List<WebExceptionHandler> getExceptionHandlers() { 062 return this.exceptionHandlers; 063 } 064 065 066 @Override 067 public Mono<Void> handle(ServerWebExchange exchange) { 068 Mono<Void> completion; 069 try { 070 completion = super.handle(exchange); 071 } 072 catch (Throwable ex) { 073 completion = Mono.error(ex); 074 } 075 076 for (WebExceptionHandler handler : this.exceptionHandlers) { 077 completion = completion.onErrorResume(ex -> handler.handle(exchange, ex)); 078 } 079 return completion; 080 } 081 082 083 /** 084 * WebExceptionHandler to insert a checkpoint with current URL information. 085 * Must be the first in order to ensure we catch the error signal before 086 * the exception is handled and e.g. turned into an error response. 087 * @since 5.2 088 */ 089 private static class CheckpointInsertingHandler implements WebExceptionHandler { 090 091 @Override 092 public Mono<Void> handle(ServerWebExchange exchange, Throwable ex) { 093 ServerHttpRequest request = exchange.getRequest(); 094 String rawQuery = request.getURI().getRawQuery(); 095 String query = StringUtils.hasText(rawQuery) ? "?" + rawQuery : ""; 096 HttpMethod httpMethod = request.getMethod(); 097 String description = "HTTP " + httpMethod + " \"" + request.getPath() + query + "\""; 098 return Mono.<Void>error(ex).checkpoint(description + " [ExceptionHandlingWebHandler]"); 099 } 100 } 101 102}