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1   /*
2    * Copyright 2000-2001,2004 The Apache Software Foundation.
3    * 
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    * 
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    * 
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package org.apache.jetspeed.services.portletcache;
18  
19  import javax.servlet.ServletConfig;
20  
21  // Jetspeed
22  import org.apache.jetspeed.portal.portlets.AbstractPortlet;
23  import org.apache.jetspeed.services.logging.JetspeedLogFactoryService;
24  import org.apache.jetspeed.services.logging.JetspeedLogger;
25  import org.apache.jetspeed.services.resources.JetspeedResources;
26  import org.apache.jetspeed.services.portletcache.Cacheable;
27  
28  // Turbine
29  import org.apache.turbine.services.TurbineBaseService;
30  import org.apache.turbine.services.TurbineServices;
31  import org.apache.turbine.services.cache.CachedObject;
32  import org.apache.turbine.services.cache.Refreshable;
33  import org.apache.turbine.services.cache.RefreshableCachedObject;
34  import org.apache.turbine.services.cache.ObjectExpiredException;
35  
36  
37  /***
38   * <P>This implementation of the PortletCache service is a simple adapter to
39   * the Turbine GlobalCacheService</p>
40   *
41   * @author <a href="mailto:burton@apache.org">Kevin A. Burton</a>
42   * @author <a href="mailto:raphael@apache.org">Raphaėl Luta</a>
43   * @author <a href="mailto:paulsp@apache.org">Paul Spencer</a>
44   * @version $Id: JetspeedPortletCacheService.java,v 1.10 2004/02/23 03:34:54 jford Exp $
45   */
46  public class JetspeedPortletCacheService
47  extends TurbineBaseService
48  implements PortletCacheService 
49  {
50      /***
51       * Static initialization of the logger for this class
52       */    
53      private static final JetspeedLogger logger = JetspeedLogFactoryService.getLogger(JetspeedPortletCacheService.class.getName());
54      
55      private static int DefaultTimeToLiveMillis = (JetspeedResources.getInt(TurbineServices.SERVICE_PREFIX
56      + PortletCacheService.SERVICE_NAME
57      + ".TimeToLive.default", (30 * 60 * 1000))); // 30 minutes
58      
59      /***
60       * Called during Turbine.init()
61       *
62       * @param config A ServletConfig.
63       */
64      public void init( ServletConfig config ) {
65          try {
66              logger.info( "JetspeedPortletCacheService early init()....starting!");
67              if (DefaultTimeToLiveMillis < 0) {
68                  logger.info( "JetspeedPortletCacheService - By default refreshable objects will live for ever");
69              } else {
70                  logger.info( "JetspeedPortletCacheService - By default refreshable objects will be removed after " 
71                  + DefaultTimeToLiveMillis + " Millis ( " 
72                  + (DefaultTimeToLiveMillis/(1000*60)) + " minutes " 
73                  + ((DefaultTimeToLiveMillis%(1000*60))/1000.00) 
74                  + " Seconds "+")" );
75              }
76              // no specific init required, relies on GlobalCacheService
77              logger.info( "JetspeedPortletCacheService early init()....finished!");
78          }
79          catch (Exception e) {
80              logger.error( "Cannot initialize JetspeedPortletCacheService!", e );
81          }
82          setInit(true);
83      }
84      
85      /***
86       * Add a Cacheable object to the cache.
87       *
88       * @param item the object to store in the Cache
89       */
90      public void addCacheable( Cacheable item ) {
91          
92          String handle = item.getHandle();
93          
94          if ( handle.length() == 0 ) {
95              throw new RuntimeException("You must specify a handle for the item you want to cache.");
96          }
97          
98          if ( item.isCacheable() ) {
99              CachedObject cachedObject = null;
100             Long expirationMillis = item.getExpirationMillis();
101             if (expirationMillis != null) {
102                 if (System.currentTimeMillis() < expirationMillis.longValue()) {
103                     cachedObject.setExpires(expirationMillis.longValue() - cachedObject.getCreated());
104                 }
105             }
106             if (item instanceof Refreshable) {
107                 RefreshableCachedObject rco = new RefreshableCachedObject( (Refreshable) item);
108                 if (item instanceof AbstractPortlet) {
109                     AbstractPortlet portlet = (AbstractPortlet)item;
110                     String tempString =  portlet.getPortletConfig().getInitParameter(JetspeedResources.TIME_TO_LIVE);
111                     if (tempString != null) {
112                         rco.setTTL(Integer.parseInt(tempString));
113                         if (logger.isWarnEnabled())
114                         {
115                             logger.warn("PortletCache: portlet " 
116                                      + item.getHandle() 
117                                      + " overrides default time to live with " 
118                                      + tempString);
119                         }
120                     } else {
121                         rco.setTTL(DefaultTimeToLiveMillis);
122                     }
123                 } else {
124                     rco.setTTL(DefaultTimeToLiveMillis);
125                 }
126                 cachedObject = rco;
127                 
128             } else {
129                 cachedObject = new CachedObject(item);
130             }
131             item.setCachedObject(cachedObject);
132 
133             // Add object to cache
134             GlobalCache.addObject( handle , cachedObject);
135          }
136     }
137     
138     /***
139      * Removes an object from the cache based on its handle
140      *
141      * @see PortletCacheService#removeCacheable
142      * @param handle the identifier of the object we wish to retrieve
143      */
144     public void removeCacheable( String handle ) {
145         
146         CachedObject obj = null;
147         
148         try {
149             obj = GlobalCache.getObject( handle );
150         } catch ( ObjectExpiredException e) {
151             // nothing to do if already expired
152         }
153         
154         if ( obj != null ) {
155             obj.setStale(true);
156         }
157     }
158     
159     /***
160      * Retrieves a Cacheable object from the cache.
161      *
162      * @param handle the identifier of the object we wish to retrieve
163      * @return the cacehd object or null if not found
164      */
165     public Cacheable getCacheable( String handle ) {
166         
167         CachedObject obj = null;
168         
169         try {
170             obj = GlobalCache.getObject( handle );
171         } catch (ObjectExpiredException e) {
172             logger.info( "cache miss, object expired: " + handle );
173         }
174         
175         if ( obj == null ) {
176             //Log.info( "cache miss: " + handle );
177             return null;
178         } /*else {
179             Log.info( "cache hit: " + handle );
180             } */
181         
182         return (Cacheable)obj.getContents();
183         
184     }
185     
186 }
187