org.springframework.web.cors.reactive.CorsWebFilter Maven / Gradle / Ivy
/*
* 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
*
* https://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.springframework.web.cors.reactive;
import reactor.core.publisher.Mono;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.util.Assert;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.server.WebFilter;
import org.springframework.web.server.WebFilterChain;
/**
* {@link WebFilter} that handles CORS preflight requests and intercepts
* CORS simple and actual requests thanks to a {@link CorsProcessor} implementation
* ({@link DefaultCorsProcessor} by default) in order to add the relevant CORS
* response headers (like {@code Access-Control-Allow-Origin}) using the provided
* {@link CorsConfigurationSource} (for example an {@link UrlBasedCorsConfigurationSource}
* instance.
*
* This is an alternative to Spring WebFlux Java config CORS configuration,
* mostly useful for applications using the functional API.
*
* @author Sebastien Deleuze
* @since 5.0
* @see CORS W3C recommendation
*/
public class CorsWebFilter implements WebFilter {
private final CorsConfigurationSource configSource;
private final CorsProcessor processor;
/**
* Constructor accepting a {@link CorsConfigurationSource} used by the filter
* to find the {@link CorsConfiguration} to use for each incoming request.
* @see UrlBasedCorsConfigurationSource
*/
public CorsWebFilter(CorsConfigurationSource configSource) {
this(configSource, new DefaultCorsProcessor());
}
/**
* Constructor accepting a {@link CorsConfigurationSource} used by the filter
* to find the {@link CorsConfiguration} to use for each incoming request and a
* custom {@link CorsProcessor} to use to apply the matched
* {@link CorsConfiguration} for a request.
* @see UrlBasedCorsConfigurationSource
*/
public CorsWebFilter(CorsConfigurationSource configSource, CorsProcessor processor) {
Assert.notNull(configSource, "CorsConfigurationSource must not be null");
Assert.notNull(processor, "CorsProcessor must not be null");
this.configSource = configSource;
this.processor = processor;
}
@Override
public Mono filter(ServerWebExchange exchange, WebFilterChain chain) {
ServerHttpRequest request = exchange.getRequest();
if (CorsUtils.isCorsRequest(request)) {
CorsConfiguration corsConfiguration = this.configSource.getCorsConfiguration(exchange);
if (corsConfiguration != null) {
boolean isValid = this.processor.process(corsConfiguration, exchange);
if (!isValid || CorsUtils.isPreFlightRequest(request)) {
return Mono.empty();
}
}
}
return chain.filter(exchange);
}
}