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1 package org.apache.ojb.otm.swizzle;
2
3
17
18 import java.lang.reflect.Array  ;
19 import java.util.Collection ;
20 import java.util.Iterator ;
21 import java.util.List ;
22 import java.util.Set ;
23 import org.apache.ojb.broker.Identity;
24 import org.apache.ojb.broker.PersistenceBroker;
25 import org.apache.ojb.broker.cache.ObjectCache;
26 import org.apache.ojb.broker.core.proxy.CollectionProxyDefaultImpl;
27 import org.apache.ojb.broker.core.proxy.ListProxyDefaultImpl;
28 import org.apache.ojb.broker.core.proxy.SetProxyDefaultImpl;
29 import org.apache.ojb.broker.metadata.ClassDescriptor;
30 import org.apache.ojb.broker.metadata.CollectionDescriptor;
31 import org.apache.ojb.broker.metadata.FieldDescriptor;
32 import org.apache.ojb.broker.metadata.ObjectReferenceDescriptor;
33 import org.apache.ojb.broker.metadata.fieldaccess.PersistentField;
34
35 public class CopySwizzling implements Swizzling
36 {
37
38
41 public Object swizzle(Object newObj, Object oldObj, PersistenceBroker pb,
42 ObjectCache cache)
43 {
44 if (newObj == null) {
46 return null;
47 }
48
49 if (oldObj == null)
50 {
51 return newObj;
52 }
53
54 if (!newObj.getClass().equals(oldObj.getClass()))
55 {
56 System.err.println("Cannot swizzle objects of different classes: "
57 + newObj.getClass() + " and " + oldObj.getClass());
58 return newObj;
59 }
60
61 ClassDescriptor mif = pb.getClassDescriptor(newObj.getClass());
62 FieldDescriptor[] fieldDescs = mif.getFieldDescriptions();
63
64 for (int i = 0; i < fieldDescs.length; i++)
65 {
66 FieldDescriptor fd = fieldDescs[i];
67 PersistentField f = fd.getPersistentField();
68 f.set(oldObj, f.get(newObj));
69 }
70
71 Iterator iter = mif.getObjectReferenceDescriptors().iterator();
73 ObjectReferenceDescriptor rds;
74 PersistentField field;
75 Object newRelObj;
76 Identity newRelOid;
77 Object oldRelObj;
78
79 while (iter.hasNext())
80 {
81 rds = (ObjectReferenceDescriptor) iter.next();
82 field = rds.getPersistentField();
83 newRelObj = field.get(newObj);
84 oldRelObj = field.get(oldObj);
85 if ((newRelObj == null) && (oldRelObj != null))
86 {
87 field.set(oldObj, null);
88 }
89 else if (newRelObj != null)
90 {
91 newRelOid = new Identity(newRelObj, pb);
92 if ((oldRelObj == null) ||
93 !newRelOid.equals(new Identity(oldRelObj, pb)))
94 {
95 oldRelObj = cache.lookup(newRelOid);
97 if (oldRelObj == null)
98 {
99 throw new IllegalStateException ("Related object not found in the context: " + newRelOid);
100 }
101 field.set(oldObj, oldRelObj);
102 }
103 }
104 }
105
106 Iterator collections = mif.getCollectionDescriptors().iterator();
108 CollectionDescriptor collectionDescriptor;
109
110 while (collections.hasNext())
111 {
112 collectionDescriptor = (CollectionDescriptor) collections.next();
113 field = collectionDescriptor.getPersistentField();
114 if (Collection .class.isAssignableFrom(field.getType()))
115 {
116 Collection newCol;
117 Collection oldCol;
118
119 newCol = (Collection ) field.get(newObj);
120 if (newCol == null)
121 {
122 field.set(oldObj, null);
123 continue;
124 }
125
126 oldCol = (Collection ) field.get(oldObj);
127 if (newCol instanceof CollectionProxyDefaultImpl)
128 {
129 CollectionProxyDefaultImpl cp = (CollectionProxyDefaultImpl) newCol;
130 if (newCol instanceof List )
131 {
132 oldCol = new ListProxyDefaultImpl(pb.getPBKey(), cp.getCollectionClass(), cp.getQuery());
133 }
134 else if (newCol instanceof Set )
135 {
136 oldCol = new SetProxyDefaultImpl(pb.getPBKey(), cp.getCollectionClass(), cp.getQuery());
137 }
138 else
139 {
140 oldCol = new CollectionProxyDefaultImpl(pb.getPBKey(), cp.getCollectionClass(), cp.getQuery());
141 }
142 if (!((CollectionProxyDefaultImpl) newCol).isLoaded())
143 {
144 field.set(oldObj, oldCol);
145 continue;
146 }
147 oldCol.clear();
148 }
149 else
150 {
151 try
152 {
153 oldCol = (Collection ) newCol.getClass().newInstance();
154 }
155 catch (Exception ex)
156 {
157 System.err.println("Cannot instantiate collection field which is neither Collection nor array: " + field);
158 ex.printStackTrace();
159 return newObj;
160 }
161 }
162 field.set(oldObj, oldCol);
163 for (Iterator it = newCol.iterator(); it.hasNext(); )
164 {
165 newRelObj = it.next();
166 newRelOid = new Identity(newRelObj, pb);
167 oldRelObj = cache.lookup(newRelOid);
168 if (oldRelObj == null)
169 {
170 oldRelObj = newRelObj;
171 }
172 oldCol.add(oldRelObj);
173 }
174 }
175 else if (field.getType().isArray())
176 {
177 Object newArray = field.get(newObj);
178 int length = Array.getLength(newArray);
179 Object oldArray =
180 Array.newInstance(field.getType().getComponentType(), length);
181
182 for (int i = 0; i < length; i++)
183 {
184 newRelObj = Array.get(newArray, i);
185 newRelOid = new Identity(newRelObj, pb);
186 oldRelObj = cache.lookup(newRelOid);
187 if (oldRelObj == null)
188 {
189 throw new IllegalStateException ("Related object not found for swizzle: " + newRelOid);
190 }
191 Array.set(oldArray, i, oldRelObj);
192 }
193 field.set(oldObj, oldArray);
194 }
195 else
196 {
197 throw new IllegalStateException ("Cannot swizzle collection field: " + field);
198 }
199 }
200
201 return oldObj;
202 }
203
204
207 public boolean isSameInstance(Object swizzledObject, Object object)
208 {
209 return (swizzledObject == object);
210 }
211
212
215 public Object getRealTarget(Object swizzledObject)
216 {
217 return swizzledObject;
218 }
219
220 }
221 |
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