http://micronaut.io: Natively Cloud Native
  • Graeme Rocher 
/*
 * Copyright 2017-2020 original 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 io.micronaut.http.filter;

import io.micronaut.core.order.Ordered;
import io.micronaut.http.HttpRequest;
import io.micronaut.http.HttpResponse;
import org.reactivestreams.Publisher;


A interface for classes that can intercept and filter HttpRequest instances and can either proceed with the request or return a modified result.




Implementations are passed a FilterChain where the last entry in the chain in the action to be executed that returns a Publisher that emits an HttpResponse




Each filter implements Ordered and can return an order to increase or decrease the priority of the filter




To modify the request filters can either wrap it (using HttpRequestWrapper or pass it along the chain as is




The response can be altered by returning an alternative Publisher that emits a HttpResponse or by altering the publisher returned by FilterChain.proceed(HttpRequest<?>)


Author:Graeme Rocher
Since:1.0
/**
 * <p>A interface for classes that can intercept and filter {@link io.micronaut.http.HttpRequest} instances and can
 * either proceed with the request or return a modified result.</p>
 * <p>
 * <p>Implementations are passed a {@link FilterChain} where the last entry in the chain in the action to be executed
 * that returns a {@link Publisher} that emits an {@link HttpResponse}</p>
 * <p>
 * <p>Each filter implements {@link Ordered} and can return an order to increase or decrease the priority of the filter</p>
 * <p>
 * <p>To modify the request filters can either wrap it (using {@link io.micronaut.http.HttpRequestWrapper} or pass it
 * along the chain as is</p>
 * <p>
 * <p>The response can be altered by returning an alternative {@link Publisher} that emits a {@link HttpResponse} or
 * by altering the publisher returned by {@link FilterChain#proceed(HttpRequest)}</p>
 *
 * @author Graeme Rocher
 * @since 1.0
 */
public interface HttpFilter extends Ordered {

    
Intercepts a HttpRequest. 
Params:
Returns:A Publisher for the Http response
/**
     * Intercepts a {@link HttpRequest}.
     *
     * @param request The {@link HttpRequest} instance
     * @param chain   The {@link FilterChain} instance
     * @return A {@link Publisher} for the Http response
     */
    Publisher<? extends HttpResponse<?>> doFilter(HttpRequest<?> request, FilterChain chain);
}