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 2015 ForgeRock AS.
015 */
016package org.forgerock.http.filter;
017
018import org.forgerock.http.Filter;
019import org.forgerock.http.Handler;
020import org.forgerock.http.header.MalformedHeaderException;
021import org.forgerock.http.header.TransactionIdHeader;
022import org.forgerock.http.protocol.Request;
023import org.forgerock.http.protocol.Response;
024import org.forgerock.services.context.Context;
025import org.forgerock.services.context.TransactionIdContext;
026import org.forgerock.util.promise.NeverThrowsException;
027import org.forgerock.util.promise.Promise;
028import org.slf4j.Logger;
029import org.slf4j.LoggerFactory;
030
031/**
032 * This filter aims to create a sub-transaction's id and inserts that value as a header of the request.
033 *
034 * Its main usage will be like this :
035 * <pre>
036 * {@code
037 * Handler handler = Handlers.chainOf(new HttpClientHandler(httpClient), new TransactionIdOutboundFilter());
038 * }
039 * </pre>
040 *
041 */
042public class TransactionIdOutboundFilter implements Filter {
043
044    private static final Logger logger = LoggerFactory.getLogger(TransactionIdOutboundFilter.class);
045
046    @Override
047    public Promise<Response, NeverThrowsException> filter(Context context, Request request, Handler next) {
048        if (context.containsContext(TransactionIdContext.class)) {
049            TransactionIdContext txContext = context.asContext(TransactionIdContext.class);
050            final String subTxId = txContext.getTransactionId().createSubTransactionId().getValue();
051            try {
052                request.getHeaders().put(new TransactionIdHeader(subTxId));
053            } catch (MalformedHeaderException ex) {
054                // Should not happen as the value is always valid.
055                logger.error("An error occured while building the TransactionIdHeader", ex);
056            }
057        } else {
058            logger.trace("Expecting to find an instance of TransactionIdContext in the chain, but there was none.");
059        }
060
061        return next.handle(context, request);
062    }
063
064}