我有问题序列化和反序列化在同一个JVM中的对象列表。确切的说,现在我的目标持同样引用的Alphabet
对象,它具有以下规则:java反序列化和序列化在相同的过程
VMID instanceId = new VMID(); //used in readResolve to identify persitent instances
public Alphabet (int capacity, Class entryClass) {
this.map = new gnu.trove.TObjectIntHashMap (capacity);
this.entries = new ArrayList (capacity);
this.entryClass = entryClass;
// someone could try to deserialize us into this image (e.g., by RMI). Handle this.
deserializedEntries.put (instanceId, this);
}
public VMID getInstanceId() {
return instanceId;
} // for debugging
public void setInstanceId(VMID id) { this.instanceId = id; }
// Serialization
private static final long serialVersionUID = 1;
private static final int CURRENT_SERIAL_VERSION = 1;
private void writeObject (ObjectOutputStream out) throws IOException {
out.writeInt (CURRENT_SERIAL_VERSION);
out.writeInt (entries.size());
for (int i = 0; i < entries.size(); i++) {
out.writeObject (entries.get(i));
}
out.writeBoolean (growthStopped);
out.writeObject (entryClass);
out.writeObject(instanceId);
}
private void readObject (ObjectInputStream in) throws IOException, ClassNotFoundException {
int version = in.readInt();
int size = in.readInt();
entries = new ArrayList (size);
map = new gnu.trove.TObjectIntHashMap (size);
for (int i = 0; i < size; i++) {
Object o = in.readObject();
map.put (o, i);
entries. add (o);
}
growthStopped = in.readBoolean();
entryClass = (Class) in.readObject();
if (version >0){ // instanced id added in version 1S
instanceId = (VMID) in.readObject();
}
}
private transient static HashMap deserializedEntries = new HashMap();
/**
* This gets called after readObject; it lets the object decide whether
* to return itself or return a previously read in version.
* We use a hashMap of instanceIds to determine if we have already read
* in this object.
* @return
* @throws ObjectStreamException
*/
public Object readResolve() throws ObjectStreamException {
Object previous = deserializedEntries.get(instanceId);
if (previous != null){
//System.out.println(" ***Alphabet ReadResolve:Resolving to previous instance. instance id= " + instanceId);
return previous;
}
if (instanceId != null){
deserializedEntries.put(instanceId, this);
}
//System.out.println(" *** Alphabet ReadResolve: new instance. instance id= " + instanceId);
return this;
}
现在AFTE我的对象名单,反序列化,在某些点上字母引用犯规投其所好。我做了检查使用以下:
for (Instance i: finalTrainingDocs){
if (!i.getTargetAlphabet().equals(finalTraining.getTargetAlphabet())){
System.out.println("not equals");
System.out.println(i.getTargetAlphabet().getInstanceId() + " " + finalTraining.getTargetAlphabet().getInstanceId());
}
finalTraining.add(i);
counter++;
System.out.println("counter " + counter);
}
而且将得到以下结果
counter 237
counter 238
counter 239
not equals
3ce62156867eb540:6b7f0de5:141e51fcd67:-7ffa 3ce62156867eb540:6b7f0de5:141e51fcd67:-7ffa
现在看VMID,因为它们是相同的,应该不会是同一个对象,如上面的逻辑?感谢您的帮助。
那些writeObject()和readObject()方法似乎不会比默认情况下添加任何值。 – EJP
似乎喜欢它。它来自一个叫做木槌的开源库,所以我不确定作者的意图是什么 – goh
我不认为有足够的代码来弄清楚这里发生了什么。例如,如何实现'Alphabet.equals',以及VMID的代码在哪里? –