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Java > Open Source Codes > org > apache > jetspeed > services > portletcache > Cacheable


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 org.apache.jetspeed.portal.expire.Expire;
20 import org.apache.turbine.services.cache.CachedObject;
21
22 /**
23  * <p>This is an interface for defining Jetspeed objects that may be
24  * cached in the object cache.</p>
25  * <p>Each such object must be able to prodive a caching handle
26  * that will uniquely identify it within the cache system</p>
27  *
28  * @author <a HREF="mailto:burton@apache.org">Kevin A. Burton</a>
29  * @author <a HREF="mailto:raphael@apache.org">Raphaël Luta</a>
30  * @version $Id: Cacheable.java,v 1.7 2004/02/23 03:34:54 jford Exp $
31  */
32 public interface Cacheable
33 {
34     /**
35      * Return true if this Cacheable is allowed to be cached.
36      *
37      * @return <CODE>TRUE</CODE> if object is cachable<br>
38      * <CODE>FALSE</CODE> if object is not cacheable
39      */
40     public boolean isCacheable();
41     
42     /**
43      * Set this cacheable status.
44      *
45      * @param cacheable Set the cacheability of the object
46      */
47     public void setCacheable(boolean cacheable);
48     
49     /**
50      * Used by a Cacheable object to determine when it should expire itself from
51      * the cache.
52      *
53      * @return Expire handle
54      */
55     public Expire getExpire();
56
57     /**
58      * <p>Used by the cache to get a unique reference on what you want to add
59      * and then retrieve in the future from the cache</p>
60      *
61      * <p>Most implementations should just call the CacheHandleManager with
62      * the given params within the implementation and just return this.</p>
63      *
64      * @deprecated cacheable classes should now implement a static getHandle(config) method
65      */
66     public String JavaDoc getHandle();
67
68     /***
69      * <p>Set the handle for this Cacheable.</p>
70      *
71      * <p>Note that factories should call setHandle() so that getHandle() always
72      * returns a value correctly.</p>
73      *
74      * @deprecated cacheable classes should now implement a static getHandle(config) method
75      */
76     public void setHandle( String JavaDoc handle );
77   
78     /**
79      * Return the expiration time in milliseconds.
80      *
81      * @return Expiration time in milliseconds since epoch, or null if the
82      * expiration was not set
83      */
84     public Long JavaDoc getExpirationMillis();
85
86     /**
87      * Set the expiration time in milliseconds.
88      *
89      * @param expirationMillis Set expiration in millis
90      */
91     public void setExpirationMillis( long expirationMillis);
92
93     /**
94      * This allows the associated CachedObject to be
95      * known. One use of the <code>co</code> is to set the expiration time
96      *
97      * @param co Handle to the CachedObject
98      */
99      public void setCachedObject(CachedObject co);
100 }
101
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