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1 package org.apache.ojb.broker.accesslayer;
2
3
17
18 import java.util.ArrayList  ;
19 import java.util.Collection ;
20 import java.util.HashMap ;
21 import java.util.HashSet ;
22 import java.util.Iterator ;
23 import java.util.Map ;
24
25 import org.apache.ojb.broker.Identity;
26 import org.apache.ojb.broker.PersistenceBroker;
27 import org.apache.ojb.broker.cache.ObjectCache;
28 import org.apache.ojb.broker.core.PersistenceBrokerImpl;
29 import org.apache.ojb.broker.core.proxy.IndirectionHandler;
30 import org.apache.ojb.broker.core.proxy.ProxyHelper;
31 import org.apache.ojb.broker.query.Query;
32
33
39 public class PlainPrefetcher extends BasePrefetcher
40 {
41
42 public PlainPrefetcher(PersistenceBrokerImpl aBroker, Class anItemClass)
43 {
44 super(aBroker, anItemClass);
45 }
46
47 public void prepareRelationshipSettings()
48 {
49 }
51
52 public void restoreRelationshipSettings()
53 {
54 }
56
57 protected void associateBatched(Collection proxies, Collection realSubjects)
58 {
59 PersistenceBroker pb = getBroker();
60 IndirectionHandler handler;
61 Identity id;
62 Object proxy;
63 Object realSubject;
64 HashMap realSubjectsMap = new HashMap (realSubjects.size());
65
66 for (Iterator it = realSubjects.iterator(); it.hasNext(); )
67 {
68 realSubject = it.next();
69 realSubjectsMap.put(pb.serviceIdentity().buildIdentity(realSubject), realSubject);
70 }
71
72 for (Iterator it = proxies.iterator(); it.hasNext(); )
73 {
74 proxy = it.next();
75 handler = ProxyHelper.getIndirectionHandler(proxy);
76
77 if (handler == null)
78 {
79 continue;
80 }
81
82 id = handler.getIdentity();
83 realSubject = realSubjectsMap.get(id);
84 if (realSubject != null)
85 {
86 handler.setRealSubject(realSubject);
87 }
88 }
89 }
90
91
96 protected Query[] buildPrefetchQueries(Collection proxies, Collection realSubjects)
97 {
98 Collection queries = new ArrayList ();
99 Collection idsSubset;
100 Object proxy;
101 IndirectionHandler handler;
102 Identity id;
103 Class realClass;
104 HashMap classToIds = new HashMap ();
105 Class topLevelClass = getItemClassDescriptor().getClassOfObject();
106 PersistenceBroker pb = getBroker();
107 ObjectCache cache = pb.serviceObjectCache();
108
109 for (Iterator it = proxies.iterator(); it.hasNext(); )
110 {
111 proxy = it.next();
112 handler = ProxyHelper.getIndirectionHandler(proxy);
113
114 if (handler == null)
115 {
116 continue;
117 }
118
119 id = handler.getIdentity();
120 if (cache.lookup(id) != null)
121 {
122 realSubjects.add(pb.getObjectByIdentity(id));
123 continue;
124 }
125 realClass = id.getObjectsRealClass();
126 if (realClass == null)
127 {
128 realClass = Object .class; }
130 idsSubset = (HashSet ) classToIds.get(realClass);
131 if (idsSubset == null)
132 {
133 idsSubset = new HashSet ();
134 classToIds.put(realClass, idsSubset);
135 }
136 idsSubset.add(id);
137 if (idsSubset.size() == pkLimit)
138 {
139 Query query;
140 if (realClass == Object .class)
141 {
142 query = buildPrefetchQuery(topLevelClass, idsSubset, true);
143 }
144 else
145 {
146 query = buildPrefetchQuery(realClass, idsSubset, false);
147 }
148 queries.add(query);
149 idsSubset.clear();
150 }
151 }
152
153 for (Iterator it = classToIds.entrySet().iterator(); it.hasNext(); )
154 {
155 Map.Entry entry = (Map.Entry ) it.next();
156 realClass = (Class ) entry.getKey();
157 idsSubset = (HashSet ) entry.getValue();
158 if (idsSubset.size() > 0)
159 {
160 Query query;
161 if (realClass == Object .class)
162 {
163 query = buildPrefetchQuery(topLevelClass, idsSubset, true);
164 }
165 else
166 {
167 query = buildPrefetchQuery(realClass, idsSubset, false);
168 }
169 queries.add(query);
170 }
171 }
172
173 return (Query[]) queries.toArray(new Query[queries.size()]);
174 }
175
176 protected Query buildPrefetchQuery(Class clazz, Collection ids, boolean withExtents)
177 {
178 Query query = buildPrefetchQuery(clazz, ids,
179 getDescriptorRepository().getDescriptorFor(clazz).getPkFields());
180 query.setWithExtents(withExtents);
181 return query;
182 }
183 }
184 |
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