001/*
002 * The contents of this file are subject to the terms of the Common Development and
003 * Distribution License (the License). You may not use this file except in compliance with the
004 * License.
005 *
006 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
007 * specific language governing permission and limitations under the License.
008 *
009 * When distributing Covered Software, include this CDDL Header Notice in each file and include
010 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
011 * Header, with the fields enclosed by brackets [] replaced by your own identifying
012 * information: "Portions copyright [year] [name of copyright owner]".
013 *
014 * Copyright 2014-2015 ForgeRock AS.
015 */
016
017package org.forgerock.http.filter;
018
019import java.util.Arrays;
020import java.util.List;
021
022import org.forgerock.services.context.Context;
023import org.forgerock.http.Filter;
024import org.forgerock.http.Handler;
025import org.forgerock.http.protocol.Request;
026import org.forgerock.http.protocol.Response;
027import org.forgerock.http.protocol.Status;
028import org.forgerock.util.promise.NeverThrowsException;
029import org.forgerock.util.promise.Promise;
030import org.forgerock.util.promise.Promises;
031
032/**
033 * {@link Filter} which handles OPTION HTTP requests to CREST resources.
034 */
035public final class OptionsFilter implements Filter {
036
037    /** The HTTP DELETE method. */
038    public static final String METHOD_DELETE = "DELETE";
039    /** The HTTP GET method. */
040    public static final String METHOD_GET = "GET";
041    /** The HTTP HEAD method. */
042    public static final String METHOD_HEAD = "HEAD";
043    /** The HTTP OPTIONS method. */
044    public static final String METHOD_OPTIONS = "OPTIONS";
045    /** The HTTP PATCH method. */
046    public static final String METHOD_PATCH = "PATCH";
047    /** The HTTP POST method. */
048    public static final String METHOD_POST = "POST";
049    /** The HTTP PUT method. */
050    public static final String METHOD_PUT = "PUT";
051    /** The HTTP TRACE method. */
052    public static final String METHOD_TRACE = "TRACE";
053
054    private final List<String> allowedMethods;
055
056    OptionsFilter(String... allowedMethods) {
057        this.allowedMethods = Arrays.asList(allowedMethods);
058    }
059
060    /**
061     * Handles all OPTION requests to CREST resources, all other request methods are handled by the {@link Handler}.
062     *
063     * @param context {@inheritDoc}
064     * @param request {@inheritDoc}
065     * @param next {@inheritDoc}
066     * @return {@inheritDoc}
067     */
068    @Override
069    public Promise<Response, NeverThrowsException> filter(Context context, Request request,
070            Handler next) {
071        switch (request.getMethod()) {
072        case METHOD_OPTIONS:
073            Response response = new Response(Status.OK);
074            response.getHeaders().put("Allow", allowedMethods);
075            return Promises.newResultPromise(response);
076        default:
077            return next.handle(context, request);
078        }
079    }
080}