Source Code Cross Referenced for ParameterMatcher.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:
22:        import java.util.HashMap;
23:        import java.util.Map;
24:
25:        /**
26:         * This class allows for matching based on a parameter provided from the sitemap.
27:         * If the specified sitemap parameter exists, its value is retrieved for later
28:         * sitemap substitution.
29:         *
30:         * <p><b>Example:</b></p>
31:         * <pre>
32:         * &lt;map:match type="parameter" pattern="dest"&gt;
33:         *     &lt;map:redirect-to uri="{1}"/&gt;
34:         * &lt;/map:match&gt;
35:         * </pre>
36:         *
37:         * @author <a href="mailto:vgritsenko@apache.org">Vadim Gritsenko</a>
38:         * @version CVS $Id: ParameterMatcher.java 433543 2006-08-22 06:22:54Z crossley $
39:         */
40:        public class ParameterMatcher implements  Matcher, ThreadSafe {
41:            /**
42:             * Match method to see if the sitemap parameter exists. If it does
43:             * have a value the parameter added to the array list for later
44:             * sitemap substitution.
45:             *
46:             * @param pattern name of sitemap parameter to find
47:             * @param objectModel environment passed through via cocoon
48:             * @return null or map containing value of sitemap parameter 'pattern'
49:             */
50:            public Map match(String pattern, Map objectModel,
51:                    Parameters parameters) {
52:
53:                String parameter = parameters.getParameter(pattern, null);
54:                if (parameter == null) {
55:                    return null; // no parameter defined
56:                } else {
57:                    Map map = new HashMap();
58:                    map.put("1", parameter);
59:                    return map; // parameter defined, return map
60:                }
61:            }
62:        }