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Java > Open Source Codes > org > apache > cayenne > reflect > ListProperty


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19
20 package org.apache.cayenne.reflect;
21
22 import org.apache.cayenne.Fault;
23 import org.apache.cayenne.Persistent;
24 import org.apache.cayenne.ValueHolder;
25 import org.apache.cayenne.util.PersistentObjectList;
26
27 /**
28  * Provides access to a property implemented as a List Field.
29  *
30  * @since 1.2
31  * @author Andrus Adamchik
32  */
33 public class ListProperty extends BaseToManyProperty {
34
35     public ListProperty(ClassDescriptor owner, ClassDescriptor targetDescriptor,
36             Accessor accessor, String JavaDoc reverseName) {
37         super(owner, targetDescriptor, accessor, reverseName);
38     }
39
40     /**
41      * Creates a List for an object. Expects an object to be an instance of Persistent.
42      */
43     protected ValueHolder createCollectionValueHolder(Object JavaDoc object)
44             throws PropertyException {
45         if (!(object instanceof Persistent)) {
46
47             throw new PropertyException(
48                     "ValueHolders for non-persistent objects are not supported.",
49                     this,
50                     object);
51         }
52
53         return new PersistentObjectList((Persistent) object, getName());
54     }
55
56     public boolean isFault(Object JavaDoc object) {
57         Object JavaDoc target = accessor.getValue(object);
58         return target == null
59                 || target instanceof Fault
60                 || ((ValueHolder) target).isFault();
61     }
62
63     public void invalidate(Object JavaDoc object) {
64         ValueHolder list = (ValueHolder) readPropertyDirectly(object);
65         if(list != null) {
66             list.invalidate();
67         }
68     }
69 }
70
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