RedirectStrategy.java

/*
 * ====================================================================
 * 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
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 * <http://www.apache.org/>.
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package org.apache.hc.client5.http.protocol;

import java.net.URI;

import org.apache.hc.core5.annotation.Contract;
import org.apache.hc.core5.annotation.ThreadingBehavior;
import org.apache.hc.core5.http.HttpException;
import org.apache.hc.core5.http.HttpHost;
import org.apache.hc.core5.http.HttpRequest;
import org.apache.hc.core5.http.HttpResponse;
import org.apache.hc.core5.http.protocol.HttpContext;

/**
 * A strategy for determining if an HTTP request should be redirected to
 * a new location in response to an HTTP response received from the target
 * server.
 * <p>
 * Implementations of this interface must be thread-safe. Access to shared
 * data must be synchronized as methods of this interface may be executed
 * from multiple threads.
 * </p>
 *
 * @since 4.1
 */
@Contract(threading = ThreadingBehavior.STATELESS)
public interface RedirectStrategy {

    /**
     * Determines if a request should be redirected to a new location
     * given the response from the target server.
     *
     * @param request  the executed request
     * @param response the response received from the target server
     * @param context  the context for the request execution
     * @return {@code true} if the request should be redirected, {@code false}
     * otherwise
     */
    boolean isRedirected(
            HttpRequest request,
            HttpResponse response,
            HttpContext context) throws HttpException;

    URI getLocationURI(
            final HttpRequest request,
            final HttpResponse response,
            final HttpContext context) throws HttpException;

    /**
     * Determines if the given redirect should be executed or the redirect response
     * should be returned to the caller without further processing.
     * <p>
     * It is legal for this method implementation to modify the redirect request
     * in order to make it suitable for redirect execution.
     * </p>
     *
     * @since 5.4
     */
    default boolean isRedirectAllowed(
            HttpHost currentTarget,
            HttpHost newTarget,
            HttpRequest redirect,
            HttpContext context) {
        return true;
    }

}