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

001:        /*
002:         * Licensed to the Apache Software Foundation (ASF) under one or more
003:         * contributor license agreements.  See the NOTICE file distributed with
004:         * this work for additional information regarding copyright ownership.
005:         * The ASF licenses this file to You under the Apache License, Version 2.0
006:         * (the "License"); you may not use this file except in compliance with
007:         * the License.  You may obtain a copy of the License at
008:         * 
009:         *      http://www.apache.org/licenses/LICENSE-2.0
010:         * 
011:         * Unless required by applicable law or agreed to in writing, software
012:         * distributed under the License is distributed on an "AS IS" BASIS,
013:         * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014:         * See the License for the specific language governing permissions and
015:         * limitations under the License.
016:         */
017:        package org.apache.lenya.cms.cocoon.selection;
018:
019:        import org.apache.cocoon.selection.Selector;
020:        import org.apache.excalibur.source.Source;
021:        import org.apache.excalibur.source.SourceNotFoundException;
022:        import org.apache.excalibur.source.SourceResolver;
023:        import org.apache.avalon.framework.activity.Disposable;
024:        import org.apache.avalon.framework.logger.AbstractLogEnabled;
025:        import org.apache.avalon.framework.parameters.Parameters;
026:        import org.apache.avalon.framework.service.ServiceException;
027:        import org.apache.avalon.framework.service.ServiceManager;
028:        import org.apache.avalon.framework.service.Serviceable;
029:        import org.apache.avalon.framework.thread.ThreadSafe;
030:
031:        import java.util.Map;
032:
033:        /**
034:         * <p>
035:         * Last Modified Source Selector.
036:         * </p>
037:         * 
038:         * <pre>
039:         *  &lt;map:selector name="last-mod" src="org.apache.lenya.cms.cocoon.selection.LastModSourceSelector"/&gt;
040:         *
041:         *   &lt;map:select type="last-mod"&gt;
042:         *      &lt;map:parameter name="compare-to" value="{sourceToCompareTo}"/&gt;
043:         *
044:         *      &lt;map:when test="cachedsource"&gt;
045:         *         &lt;!-- executes iff cachedsource last-modified  &gt; courceToCompareTo last-modified --&gt;
046:         *         &lt;map:read src="{cachedsource}" mime-type="text/xml; charset=utf-8"/&gt;
047:         *      &lt;/map:when&gt;
048:         *      &lt;map:otherwise&gt;
049:         *         &lt;map:read src="{sourceToCompareTo}" mime-type="text/xml; charset=utf-8"/&gt;
050:         *      &lt;/map:otherwise&gt;
051:         *   &lt;/map:select&gt;
052:         * </pre>
053:         */
054:
055:        public class LastModSourceSelector extends AbstractLogEnabled implements 
056:                ThreadSafe, Serviceable, Disposable, Selector {
057:
058:            private ServiceManager manager;
059:            private SourceResolver resolver;
060:            private Source source = null;
061:            private Source compare = null;
062:
063:            public void service(ServiceManager manager) throws ServiceException {
064:                this .manager = manager;
065:                this .resolver = (SourceResolver) manager
066:                        .lookup(SourceResolver.ROLE);
067:            }
068:
069:            public void dispose() {
070:                if (null != this .source) {
071:                    resolver.release(this .source);
072:                    this .source = null;
073:                }
074:                if (null != this .compare) {
075:                    resolver.release(this .compare);
076:                    this .compare = null;
077:                }
078:                this .manager.release(this .resolver);
079:                this .resolver = null;
080:                this .manager = null;
081:            }
082:
083:            public boolean select(String expression, Map objectModel,
084:                    Parameters parameters) {
085:                String sourceToCompare = parameters.getParameter("compare-to",
086:                        null);
087:                String compareToSource = expression;
088:                long sourceModDate = 0;
089:                long compareModDate = 0;
090:                try {
091:                    source = resolver.resolveURI(sourceToCompare);
092:                    sourceModDate = source.getLastModified();
093:                    compare = resolver.resolveURI(compareToSource);
094:                    compareModDate = compare.getLastModified();
095:                } catch (SourceNotFoundException e) {
096:                    return false;
097:                } catch (Exception e) {
098:                    getLogger().warn("Exception resolving resource ", e);
099:                    return false;
100:                }
101:                boolean isNewer = (compareModDate > sourceModDate);
102:
103:                return (sourceToCompare != null && isNewer);
104:
105:            }
106:        }