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1 package com.tirsen.nanning.samples.prevayler;
2
3 import java.io.Serializable  ;
4 import java.util.Date ;
5 import java.util.Set ;
6 import java.util.HashSet ;
7 import java.lang.reflect.AccessibleObject ;
8
9 import com.tirsen.nanning.Aspects;
10
11 public class IdentifyingMarshaller implements Marshaller, Serializable {
12 static final long serialVersionUID = 7285806267400465332L;
13
14 public Object marshal(Object o) {
15 if (PrevaylerUtils.isPrimitive(o)) {
16 return o;
17
18 } else if (PrevaylerUtils.isStatefulService(o.getClass())) {
19 assert o instanceof Serializable : "Stateful services must be serializable";
20 return o;
21
22 } else if (PrevaylerUtils.isStatelessService(o.getClass())) {
23 return new Identity(o.getClass(), Aspects.getAspectInstance(o).getClassIdentifier());
24
25 } else if (PrevaylerUtils.isEntity(o.getClass())) {
26 if (getSystem().hasObjectID(o)) {
27 return new Identity(Aspects.getAspectInstance(o).getClassIdentifier(), new Long (getSystem().getObjectID(o)));
28 } else {
29
30 return o;
31 }
32
33 } else {
34 return o;
35 }
36 }
37
38 public Object unmarshal(Object o) {
39 if (PrevaylerUtils.isPrimitive(o)) {
40 return o;
41
42 } else if (o instanceof Identity) {
43 return resolve((Identity) o);
44
45 } else if (PrevaylerUtils.isEntity(o.getClass())) {
46 if (!getSystem().hasObjectID(o)) {
47 registerObjectIDsRecursive(o);
48 }
49 return o;
50
51 } else {
52 return o;
53 }
54 }
55
56 private IdentifyingSystem getSystem() {
57 Object system = CurrentPrevayler.getSystem();
58 assert system instanceof IdentifyingSystem : "I need an identifying system to work";
59 return (IdentifyingSystem) system;
60 }
61
62 private Object resolve(Identity identity) {
63 Class objectClass = identity.getObjectClass();
64 if (PrevaylerUtils.isStatelessService(objectClass)) {
65 return Aspects.getCurrentAspectFactory().newInstance((Class ) identity.getIdentifier());
66 }
67 if (PrevaylerUtils.isEntity(objectClass)) {
68 long oid = ((Long ) identity.getIdentifier()).longValue();
69 assert getSystem().isIDRegistered(oid) : "object of type " + Aspects.getRealClass(objectClass) + " had invalid object id " + oid;
70 return getSystem().getObjectWithID(oid);
71 }
72 throw new IllegalArgumentException ("Can't resolve objects of " + objectClass);
73 }
74
75 private void registerObjectIDsRecursive(final Object objectToRegister) {
76 final IdentifyingSystem system = getSystem();
77 final Set registeredObjects = new HashSet ();
78
79 ObjectGraphVisitor.visit(objectToRegister, new ObjectGraphVisitor() {
80 protected void visit(Object o) {
81 if (o instanceof AccessibleObject ) {
82 return;
83 }
84 if (o instanceof Date ) {
85 return;
86 }
87 if (PrevaylerUtils.isPrimitive(o)) {
88 return;
89 }
90 if (!registeredObjects.contains(o) && PrevaylerUtils.isEntity(o.getClass())) {
91 assert !system.hasObjectID(o) : "you're mixing objects in prevayler with objects outside, this will lead to unpredictable results, " +
92 "so I've banished that sort of behaviour with this assert here" +
93 "(the object that was inside prevayler was " + o + " the object that was outside was " + objectToRegister + ")";
94
95 system.registerObjectID(o);
96 registeredObjects.add(o);
97 }
98
99
100 if (Aspects.isAspectObject(o)) {
101 Object [] targets = Aspects.getTargets(o);
102 for (int i = 0; i < targets.length; i++) {
103 super.visit(targets[i]);
104 }
105 } else {
106 super.visit(o);
107 }
108 }
109 });
110 }
111 }
112 |
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