1 /***
2 * Copyright 2003-2010 Terracotta, Inc.
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 net.sf.ehcache.search;
18
19 import java.util.List;
20
21 /***
22 * Represents a single cache entry that has been selected by a cache query.
23 * <p/>
24 *
25 * @author teck
26 * @author Greg Luck
27 */
28 public interface Result {
29
30 /***
31 * Return the key for this cache entry.
32 *
33 * @return key object
34 * @throws SearchException if keys were not selected by the originating query
35 */
36 Object getKey() throws SearchException;
37
38 /***
39 * Return the value for this cache entry.
40 *
41 * @return value object. This value might be null if the value is no longer referenced
42 * by the cache (ie. a concurrent update removed this entry).
43 * @throws SearchException if values were not selected by the originating query
44 */
45 Object getValue() throws SearchException;
46
47 /***
48 * Retrieve the given attribute value for this cache entry
49 *
50 * @param attribute the attribute to retrieve
51 * @return the attribute value, or null if there is none
52 * @throws SearchException if the given attribute was not explicitly selected by the
53 * originating query
54 */
55 <T> T getAttribute(Attribute<T> attribute) throws SearchException;
56
57 /***
58 * Retrieve the aggregator value(s)
59 *
60 * @return the aggregators value as a {@link List}. The aggregator results will be in the same order they were added to the query
61 * @throws SearchException if no aggregators were requested in the query
62 */
63 List<Object> getAggregatorResults() throws SearchException;
64
65 }