1 /**
2 * Copyright 2005-2015 The Kuali Foundation
3 *
4 * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
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 package org.kuali.rice.krad.data;
17
18 import java.io.Serializable;
19 import java.util.Collections;
20 import java.util.HashMap;
21 import java.util.Map;
22
23 /**
24 * Stores the values for a multi-valued key. This is intended primarily for use on
25 * {@link DataObjectService#find(Class, Object)} in situations where you have a data object which has a compound
26 * primary key represented by more than one field. In such cases the keys in the map you construction this class with
27 * should be the field names of the primary key fields, and the values in the maps should be the values by which you
28 * want to perform the find.
29 *
30 * @author Kuali Rice Team (rice.collab@kuali.org)
31 */
32 public final class CompoundKey implements Serializable {
33
34 private static final long serialVersionUID = 1L;
35
36 private final Map<String, ?> keys;
37
38 /**
39 * Construct a new instance of a CompoundKey from the given key values map.
40 *
41 * @param keys map of field name to value for the compound key, must be non-null and non-empty
42 *
43 * @throws IllegalArgumentException if the given Map is null or empty
44 */
45 public CompoundKey(Map<String, ?> keys) {
46 if (keys == null || keys.isEmpty()) {
47 throw new IllegalArgumentException("Compound key map should be non-null as well as having at least one"
48 + "value.");
49 }
50 this.keys = new HashMap<String, Object>(keys);
51 }
52
53 /**
54 * Returns an unmodifable Map of the key values on this CompoundKey
55 *
56 * @return unmodifiable map of the key values on this CompoundKey
57 */
58 public Map<String, ?> getKeys() {
59 return Collections.unmodifiableMap(keys);
60 }
61
62 /**
63 * Returns true if any of the fields in this compound key have null values, since that usually indicates an
64 * incomplete and unsaved object.
65 *
66 * @return
67 */
68 public boolean hasNullKeyValues() {
69 for (Object value : keys.values()) {
70 if (value == null) {
71 return true;
72 }
73 }
74 return false;
75 }
76
77 }