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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.ModelException;
21  import org.apache.jdo.model.java.JavaField;
22  import org.apache.jdo.model.java.JavaProperty;
23  import org.apache.jdo.model.jdo.JDOClass;
24  import org.apache.jdo.model.jdo.JDOField;
25  import org.apache.jdo.impl.model.jdo.JDOAssociatedPropertyImplDynamic;
26  
27  /***
28   * An instance of this class represents the JDO metadata of a managed property
29   * of a persistence capable class. This JDOProperty implementation is used for
30   * persistent properties with an associated JDOField. All JDOField getter
31   * methods delegate to the associated JDOField, except methods getName,
32   * getDeclaringClass and getJavaField. All JDOField setter method throw a
33   * ModelException to avoid changing the associated JDOField through this
34   * JDOProperty instance. This caching implementation caches any calculated
35   * value to avoid re-calculating it if it is requested again. 
36   *
37   * @author Michael Bouschen
38   * @since 2.0
39   * @version 2.0
40   */
41  public class JDOAssociatedPropertyImplCaching
42      extends JDOAssociatedPropertyImplDynamic
43  {
44      /*** Constructor. */
45      protected JDOAssociatedPropertyImplCaching(
46          String name, JDOClass declaringClass, JDOField associatedJDOField)
47          throws ModelException {
48          super(name, declaringClass, associatedJDOField);
49      }
50      
51      // ===== Methods specified in JDOField =====
52  
53      /***
54       * Get the corresponding JavaProperty representation for this JDOProperty.
55       * @return the corresponding JavaProperty representation
56       */
57      public JavaField getJavaField() {
58          if (javaProperty == null) {
59              javaProperty = (JavaProperty)super.getJavaField();
60          }
61          return javaProperty;
62      }
63  }