Source Code Cross Referenced for HeaderMatcher.java in  » Content-Management-System » apache-lenya-2.0 » org » apache » cocoon » matching » Java Source Code / Java DocumentationJava Source Code and Java Documentation

01:        /*
02:         * Licensed to the Apache Software Foundation (ASF) under one or more
03:         * contributor license agreements.  See the NOTICE file distributed with
04:         * this work for additional information regarding copyright ownership.
05:         * The ASF licenses this file to You under the Apache License, Version 2.0
06:         * (the "License"); you may not use this file except in compliance with
07:         * the License.  You may obtain a copy of the License at
08:         * 
09:         *      http://www.apache.org/licenses/LICENSE-2.0
10:         * 
11:         * Unless required by applicable law or agreed to in writing, software
12:         * distributed under the License is distributed on an "AS IS" BASIS,
13:         * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14:         * See the License for the specific language governing permissions and
15:         * limitations under the License.
16:         */
17:        package org.apache.cocoon.matching;
18:
19:        import org.apache.avalon.framework.parameters.Parameters;
20:        import org.apache.avalon.framework.thread.ThreadSafe;
21:        import org.apache.cocoon.environment.ObjectModelHelper;
22:        import org.apache.cocoon.environment.Request;
23:
24:        import java.util.HashMap;
25:        import java.util.Map;
26:
27:        /**
28:         * This class allows for matching based on a request header.
29:         * If the specified request header parameter exists, its value is
30:         * retrieved for later sitemap substitution.
31:         *
32:         * <p><b>Example:</b></p>
33:         * <pre>
34:         * &lt;map:match type="header" pattern="referer"&gt;
35:         *     &lt;map:redirect-to uri="{1}"/&gt;
36:         * &lt;/map:match&gt;
37:         * </pre>
38:         *
39:         * @author <a href="mailto:vgritsenko@apache.org">Vadim Gritsenko</a>
40:         * @version CVS $Id: HeaderMatcher.java 433543 2006-08-22 06:22:54Z crossley $
41:         */
42:        public class HeaderMatcher implements  Matcher, ThreadSafe {
43:            /**
44:             * Match method to see if the request header exists. If it does
45:             * have a value the header added to the array list for later
46:             * sitemap substitution.
47:             *
48:             * @param pattern name of request header to find
49:             * @param objectModel environment passed through via cocoon
50:             * @return null or map containing value of request header 'pattern'
51:             */
52:            public Map match(String pattern, Map objectModel,
53:                    Parameters parameters) {
54:                Request request = ObjectModelHelper.getRequest(objectModel);
55:
56:                String value = request.getHeader(pattern);
57:                if (value == null) {
58:                    return null; // no request header defined
59:                } else {
60:                    Map map = new HashMap();
61:                    map.put("1", value);
62:                    return map; // request header defined, return map
63:                }
64:            }
65:        }