Java Hashtable and serialization

Question

Hi ..

I have a problem in Java hashtable serialization that seems illogical to me but i am not able to find out the error in the logic i am using. Here is what i am doing,

Hashtable sspsrpData = new Hashtable();
for(int i=0;i<Constants.secondayStructures.length;i++) {
    SecondaryStructures ss = (SecondaryStructures)(data.get(Constants.secondayStructures[i]));
    sspsrpData.put(Constants.secondayStructures[i], new SecStrucPSRP(ss.getSecStruct(),ss.getLengthCounts())); 
}
 FileOutputStream fos = null;
 ObjectOutputStream out = null;
    fos = new FileOutputStream(Constants.sspsrpData);
    out = new ObjectOutputStream(fos);
    out.writeObject(sspsrpData);

This piece of code should put 3 key-value pairs in the hashtable and also should serialize the thus formed hashtable. Now when i am trying to retrive them back in another program by this piece of code:

FileInputStream fis = null;
ObjectInputStream in = null;
fis = new FileInputStream(Constants.sspsrpData);
in = new ObjectInputStream(fis);
ssPsrp = (Hashtable)in.readObject();

The resulting hashtable has only 2 key-value pairs. Though the count in the hashtable says 3 i can only see 2 key value pairs in the hashtable. I do not understand whats going wrong!!

Can somebody point out where am i going wrong?

Thanks and Good day, Santhosh

Answer 1

Are the objects in the hashtable serializable?

Answer 2

Yes .. The strange thing all the 3 key-value pairs are identical (String - SecStrucPSRP object). All the objects are serializable. Only 2 of them are accessible while deserializing the hashtable ..

Answer 3

Maybe Constants.secondayStructures[0] .equals( Constants.secondayStructures[1] ) or Constants.secondayStructures[1] .equals( Constants.secondayStructures[2] )

Try a sspsrpData.size() before serialize your object, to be sure it has the good size before serializing.