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1   /*
2    * This file is part of Waarp Project (named also Waarp or GG).
3    *
4    *  Copyright (c) 2019, Waarp SAS, and individual contributors by the @author
5    *  tags. See the COPYRIGHT.txt in the distribution for a full listing of
6    * individual contributors.
7    *
8    *  All Waarp Project is free software: you can redistribute it and/or
9    * modify it under the terms of the GNU General Public License as published by
10   * the Free Software Foundation, either version 3 of the License, or (at your
11   * option) any later version.
12   *
13   * Waarp is distributed in the hope that it will be useful, but WITHOUT ANY
14   * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
15   * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
16   *
17   *  You should have received a copy of the GNU General Public License along with
18   * Waarp . If not, see <http://www.gnu.org/licenses/>.
19   */
20  
21  package org.waarp.openr66.protocol.http.restv2.resthandlers;
22  
23  import io.netty.channel.ChannelHandlerContext;
24  import io.netty.channel.SimpleChannelInboundHandler;
25  import io.netty.handler.codec.http.FullHttpRequest;
26  import org.waarp.common.logging.WaarpLogger;
27  import org.waarp.common.logging.WaarpLoggerFactory;
28  import org.waarp.gateway.kernel.rest.RestConfiguration;
29  import org.waarp.openr66.protocol.http.rest.HttpRestR66Handler;
30  
31  import static org.waarp.openr66.protocol.http.restv2.RestConstants.*;
32  
33  /**
34   * Handles the dispatching of incoming request between version 1 and 2 of the
35   * REST API. By default, the
36   * pipeline continues with the v2 handler, but if the request URI does not match
37   * the pattern of a v2 entry
38   * point, then the pipeline will switch to the v1 handler.
39   */
40  public class RestVersionHandler
41      extends SimpleChannelInboundHandler<FullHttpRequest> {
42  
43    /**
44     * Logger for all unexpected execution events.
45     */
46    private static final WaarpLogger logger =
47        WaarpLoggerFactory.getLogger(RestVersionHandler.class);
48  
49    /**
50     * Name of this handler in the Netty pipeline.
51     */
52    public static final String HANDLER_NAME = "version_handler";
53  
54    /**
55     * Name of the RESTv1 handler in the Netty pipeline.
56     */
57    private static final String V1_HANDLER = "v1_handler";
58  
59    /**
60     * The RESTv1 handler.
61     */
62    private final HttpRestR66Handler restV1Handler;
63  
64    /**
65     * Initializes the REST version splitter and handler with the given {@link
66     * RestConfiguration}
67     *
68     * @param restConfiguration the RestConfiguration object
69     */
70    public RestVersionHandler(final RestConfiguration restConfiguration) {
71      super(false);
72      HttpRestR66Handler.instantiateHandlers(restConfiguration);
73      restV1Handler = new HttpRestR66Handler(restConfiguration);
74    }
75  
76    /**
77     * Dispatches the incoming request to the corresponding v1 or v2 REST
78     * handler.
79     *
80     * @param ctx the Netty pipeline context
81     * @param request the incoming request
82     */
83    @Override
84    protected void channelRead0(final ChannelHandlerContext ctx,
85                                final FullHttpRequest request) {
86      logger.debug("{} received on {}", request.method(), request.uri());
87  
88      if (request.uri().startsWith(VERSION_PREFIX)) {
89        if (ctx.pipeline().get(V1_HANDLER) != null) {
90          ctx.pipeline().remove(V1_HANDLER);
91        }
92  
93        ctx.fireChannelRead(request);
94      } else {
95        if (ctx.pipeline().get(V1_HANDLER) == null) {
96          ctx.pipeline().addAfter(HANDLER_NAME, V1_HANDLER, restV1Handler);
97        }
98        ctx.fireChannelRead(request);
99      }
100   }
101 }