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1 package com.tirsen.nanning.samples.prevayler;
2
3 import java.util.*;
4
5 import org.prevayler.util.clock.AbstractClockedSystem;
6 import org.apache.commons.logging.Log;
7 import org.apache.commons.logging.LogFactory;
8
9 public class BasicIdentifyingSystem extends AbstractClockedSystem implements IdentifyingSystem {
10 private static final Log logger = LogFactory.getLog(BasicIdentifyingSystem.class);
11 static final long serialVersionUID = 4503034161857395426L;
12
13 private Map idToObject = SoftMap.createSoftValuesMap();
14
18 private Map objectToId = SoftMap.createSoftKeysMap();
19
20 private long nextObjectId = 0;
21
22 public void rebuildKeysMap() {
23 objectToId = SoftMap.createSoftKeysMap();
24 for (Iterator iterator = idToObject.entrySet().iterator(); iterator.hasNext();) {
25 Map.Entry entry = (Map.Entry) iterator.next();
26 Long  id = (Long ) entry.getKey();
27 Object o = entry.getValue();
28 objectToId.put(o, id);
29 }
30 }
31
32 public synchronized Object getObjectWithID(long oid) {
33 Object object = idToObject.get(new Long (oid));
34 assert object != null : "could not find object with id " + oid;
35 assert hasObjectID(object) : "object is not registered " + object;
36 return object;
37 }
38
39 public synchronized long getObjectID(Object object) {
40 assert hasObjectID(object) : "object " + object + " had no object id, use registerObjectID(Object)";
41 return ((Long ) objectToId.get(object)).longValue();
42 }
43
44 public synchronized boolean hasNoRegisteredObjects() {
45 return objectToId.isEmpty();
46 }
47
48 public synchronized Collection getAllRegisteredObjects() {
49
50 Collection result = new ArrayList();
51 for (Iterator i = objectToId.entrySet().iterator(); i.hasNext();) {
52 try {
53 Map.Entry entry = (Map.Entry) i.next();
54 result.add(entry.getKey());
55 } catch (NoSuchElementException ignore) {
56
57 }
58 }
59
60 return result;
61 }
62
63 public synchronized boolean hasObjectID(Object object) {
64 return objectToId.containsKey(object);
65 }
66
67 public synchronized boolean isIDRegistered(long objectId) {
68 return idToObject.containsKey(new Long (objectId));
69 }
70
71 public synchronized long registerObjectID(final Object object) {
72 if (!CurrentPrevayler.isInTransaction()) {
73 throw new IllegalStateException ("You have to be inside a transaction to register objects");
74 }
75
76 assert object != null : "can't register null";
77 assert !hasObjectID(object) : "already has ID: " + object;
78
79 Long id = getNextId();
80 assert !isIDRegistered(id.longValue());
81
82 idToObject.put(id, object);
83 objectToId.put(object, id);
84
85 logger.debug("registering object " + object + " with id " + id);
86
87 return id.longValue();
88 }
89
90 private synchronized Long getNextId() {
91 return new Long (nextObjectId++);
92 }
93 }
94 |
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