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1
19
20 package org.apache.cayenne.access;
21
22 import java.util.ArrayList  ;
23 import java.util.Collection ;
24 import java.util.Collections ;
25 import java.util.Iterator ;
26 import java.util.List ;
27
28 import org.apache.cayenne.CayenneRuntimeException;
29 import org.apache.cayenne.DeleteDenyException;
30 import org.apache.cayenne.PersistenceState;
31 import org.apache.cayenne.Persistent;
32 import org.apache.cayenne.map.DeleteRule;
33 import org.apache.cayenne.map.ObjRelationship;
34 import org.apache.cayenne.reflect.ArcProperty;
35 import org.apache.cayenne.reflect.AttributeProperty;
36 import org.apache.cayenne.reflect.ClassDescriptor;
37 import org.apache.cayenne.reflect.PropertyVisitor;
38 import org.apache.cayenne.reflect.ToManyProperty;
39 import org.apache.cayenne.reflect.ToOneProperty;
40
41
47 class DataContextDeleteAction {
48
49 DataContext dataContext;
50
51 DataContextDeleteAction(DataContext context) {
52 this.dataContext = context;
53 }
54
55
58 boolean performDelete(Persistent object) throws DeleteDenyException {
59 int oldState = object.getPersistenceState();
60 if (oldState == PersistenceState.DELETED
61 || oldState == PersistenceState.TRANSIENT) {
62
63 return false;
68 }
69
70 if (object.getObjectContext() == null) {
71 throw new CayenneRuntimeException(
72 "Attempt to delete unregistered non-TRANSIENT object: " + object);
73 }
74
75 if (object.getObjectContext() != dataContext) {
76 throw new CayenneRuntimeException(
77 "Attempt to delete object registered in a different DataContext. Object: "
78 + object
79 + ", data context: "
80 + dataContext);
81 }
82
83
86 dataContext.prepareForAccess(object, null, false);
87
88 if (oldState == PersistenceState.NEW) {
89 deleteNew(object, oldState);
90 }
91 else {
92 deletePersistent(object, oldState);
93 }
94
95 return true;
96 }
97
98 private void deletePersistent(Persistent object, int oldState)
99 throws DeleteDenyException {
100
101 object.setPersistenceState(PersistenceState.DELETED);
102 dataContext.getObjectStore().nodeRemoved(object.getObjectId());
103 processDeleteRules(object, oldState);
104 }
105
106 private void deleteNew(Persistent object, int oldState) throws DeleteDenyException {
107 object.setPersistenceState(PersistenceState.TRANSIENT);
108 processDeleteRules(object, oldState);
109
110
112 dataContext.getObjectStore().objectsUnregistered(
113 Collections.singletonList(object));
114 object.setObjectContext(null);
115 }
116
117 private void processDeleteRules(final Persistent object, int oldState)
118 throws DeleteDenyException {
119
120 ClassDescriptor descriptor = dataContext.getEntityResolver().getClassDescriptor(
121 object.getObjectId().getEntityName());
122
123 Iterator it = descriptor.getEntity().getRelationships().iterator();
124 while (it.hasNext()) {
125 ObjRelationship relationship = (ObjRelationship) it.next();
126
127 boolean processFlattened = relationship.isFlattened()
128 && relationship.isToDependentEntity() && !relationship.isReadOnly();
129
130 if (relationship.getDeleteRule() == DeleteRule.NO_ACTION && !processFlattened) {
132 continue;
133 }
134
135 List relatedObjects = Collections.EMPTY_LIST;
136
137 ArcProperty property = (ArcProperty) descriptor.getProperty(relationship
138 .getName());
139 Object related = property.readProperty(object);
140
141 if (relationship.isToMany()) {
142
143 List toMany = (List ) related;
144 if (toMany.size() > 0) {
145 relatedObjects = new ArrayList (toMany);
148 }
149 }
150 else {
151 if (related != null) {
152 relatedObjects = Collections.singletonList(related);
153 }
154 }
155
156 if (relatedObjects.size() == 0) {
158 continue;
159 }
160
161 if (relationship.getDeleteRule() == DeleteRule.DENY) {
163 object.setPersistenceState(oldState);
164
165 String message = relatedObjects.size() == 1
166 ? "1 related object"
167 : relatedObjects.size() + " related objects";
168 throw new DeleteDenyException(object, relationship.getName(), message);
169 }
170
171 if (processFlattened) {
175 ObjectStore objectStore = dataContext.getObjectStore();
176 Iterator iterator = relatedObjects.iterator();
177 while (iterator.hasNext()) {
178 Persistent relatedObject = (Persistent) iterator.next();
179 objectStore.arcDeleted(object.getObjectId(), relatedObject
180 .getObjectId(), relationship.getName());
181 }
182 }
183
184 switch (relationship.getDeleteRule()) {
186 case DeleteRule.NO_ACTION:
187 break;
188 case DeleteRule.NULLIFY:
189 ArcProperty reverseArc = property.getComplimentaryReverseArc();
190
191 if (reverseArc == null) {
192 break;
194 }
195
196 final Collection finalRelatedObjects = relatedObjects;
197
198 reverseArc.visit(new PropertyVisitor() {
199
200 public boolean visitAttribute(AttributeProperty property) {
201 return false;
202 }
203
204 public boolean visitToMany(ToManyProperty property) {
205 Iterator iterator = finalRelatedObjects.iterator();
206 while (iterator.hasNext()) {
207 Object relatedObject = iterator.next();
208 property.removeTarget(relatedObject, object, true);
209 }
210
211 return false;
212 }
213
214 public boolean visitToOne(ToOneProperty property) {
215 Iterator iterator = finalRelatedObjects.iterator();
218 while (iterator.hasNext()) {
219 Object relatedObject = iterator.next();
220 property.setTarget(relatedObject, null, true);
221 }
222 return false;
223 }
224 });
225
226 break;
227 case DeleteRule.CASCADE:
228 Iterator iterator = relatedObjects.iterator();
230 while (iterator.hasNext()) {
231 Persistent relatedObject = (Persistent) iterator.next();
232 new DataContextDeleteAction(this.dataContext)
233 .performDelete(relatedObject);
234 }
235
236 break;
237 default:
238 object.setPersistenceState(oldState);
239 throw new CayenneRuntimeException("Invalid delete rule "
240 + relationship.getDeleteRule());
241 }
242 }
243 }
244 }
245 |
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