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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    * 
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   * 
11   * Unless required by applicable law or agreed to in writing, software 
12   * distributed under the License is distributed on an "AS IS" BASIS, 
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
14   * See the License for the specific language governing permissions and 
15   * limitations under the License.
16   */
17  
18  package org.apache.jdo.impl.model.jdo.caching;
19  
20  import org.apache.jdo.model.java.JavaType;
21  import org.apache.jdo.model.jdo.JDORelationship;
22  import org.apache.jdo.impl.model.jdo.JDOMapImplDynamic;
23  
24  /***
25   * An instance of this class represents the JDO relationship metadata 
26   * (the treatment of keys and values) of a map relationship field.  
27   * This caching implementation caches any calulated value to avoid
28   * re-calculating it if it is requested again. 
29   *
30   * @author Michael Bouschen
31   * @since 1.1
32   * @version 2.0
33   */
34  public class JDOMapImplCaching extends JDOMapImplDynamic {
35  
36      /*** 
37       * Get the mappedBy relationship. If there is no mappedBy relationship
38       * set, the method checks the mappedBy name as specified in the declaring
39       * field and resolves the relationship. The method returns
40       * <code>null</code> if there is no mappedBy relationship set and there
41       * is no mappedBy name specified on the declaring field.
42       * @return the mappedBy relationship if available; <code>null</code>
43       * otherwise.
44       */
45      public JDORelationship getMappedBy() {
46          if (mappedBy == null) {
47              mappedBy = super.getMappedBy();
48          }
49          return mappedBy;
50      }
51  
52      /***
53       * Get the inverse JDORelationship in the case of a two-way relationship.
54       * @return the inverse relationship
55       */
56      public JDORelationship getInverseRelationship() {
57          if (inverse == null) {
58              inverse = super.getInverseRelationship();
59          }
60          return inverse;
61      }    
62  
63      /***
64       * Determines whether the keys of the map should be stored if possible as 
65       * part of the instance instead of as their own instances in the datastore.
66       * @return <code>true</code> if the keys are stored as part of this instance;
67       * <code>false</code> otherwise
68       */
69      public boolean isEmbeddedKey() {
70          if (embeddedKey == null) {
71              embeddedKey =
72                  super.isEmbeddedKey() ? Boolean.TRUE : Boolean.FALSE;
73          }
74          return embeddedKey.booleanValue();
75      }
76      
77      /***
78       * Get the type representation of the keys for this JDOMap.
79       * @return the type of the keys of this JDOMap  
80       */
81      public JavaType getKeyType() {
82          if (keyType == null) {
83              keyType = super.getKeyType();
84          }
85          return keyType;
86      }
87  
88      /***
89       * Determines whether the values of the map should be stored if possible as 
90       * part of the instance instead of as their own instances in the datastore.
91       * @return <code>true</code> if the values are stored as part of this 
92       * instance; <code>false</code> otherwise
93       */
94      public boolean isEmbeddedValue() {
95          if (embeddedValue == null) {
96              embeddedValue = 
97                  super.isEmbeddedValue() ? Boolean.TRUE : Boolean.FALSE;
98          }
99          return embeddedValue.booleanValue();
100     }
101     
102     /***
103      * Get the type representation of the values for this JDOMap.
104      * @return the type of the values of this JDOMap  
105      */
106     public JavaType getValueType() {
107         if (valueType == null) {
108             valueType = super.getValueType();
109         }
110         return valueType;
111     }
112 
113 }