How to omit component's coordinates in xml serialisation

Question

Hi colleagues,
my application uses XMLEncoder to serialize JPanel component (it's coordinates). The generated XML is like this:
<object class="MyJPanel">
<void property="bounds">
<object class="java.awt.Rectangle">
<int>28</int>
<int>93</int>
<int>227</int>
<int>162</int>
</object>
</void>
</object>
Coordinates are measured in pixels. It is problem for me. I need to serialize component's coordinates in some screen independent measurement. E.g. in milimeters. I can add properties for bounds representation of the components in milimeters. But I do know, how to OMIT default bounds pixels serialization. I.e. I would like to receive serialization like this:
<object class="sk.gnome.sf9.Block">
<void property="widthInMilimeters">
<double>100</double>
</void>
<void property="heightInMilimeters">
< double >130</double >
</void>
</object>
I did some experiments with extending the SimpleBeanInfo class, but nothing was successful. Can anybody give some advice?

Answer 1

Hi,
If you wish to change the Default serialization behaviour then you have to override the read and write methods provided when you implemented Serializable.
So for example I have my own version of a hashTable which I override the readObject and writeObject methods,,, take a look at the JPanel source to see how it saves and restores the object. If no behaviour is defined then assume that EVERY global object/primitive which is not "transient" is being saved.
//** Serializable interface, write
private synchronized void writeObject(ObjectOutputStream lOOS) throws IOException
     // Write out the threshold and loadfactor
     lOOS.defaultWriteObject();
     // Write out length, count of elements and then the key/value objects
     lOOS.writeInt(table.length);
     lOOS.writeInt(size);
     for (int lCount = table.length - 1; lCount >= 0; lCount--)
     DataRListEntry lEntry = table[lCount];
     while (lEntry != null)
          lOOS.writeObject(lEntry.value);
          lEntry = lEntry.next;
//** Serializable interface, read
private void readObject(ObjectInputStream lOIS) throws IOException, ClassNotFoundException
     // Read in the threshold and loadfactor
     lOIS.defaultReadObject();
     // Read the original length of the array and number of elements
     int lLength = lOIS.readInt();
     int lSize = lOIS.readInt();
     // Compute new size with a bit of room 5% to grow but
     int lTable = (int)(lSize * loadFactor) + (lSize / 20) + 3;
     if (lTable > lSize && (lTable & 1) == 0) lTable--;
     if (lLength > 0 && lTable > lLength) lTable = lLength;
     table = new DataRListEntry[lTable];
     size = 0;
     // Read the number of elements and then all the key/value objects
     for (; lSize > 0; lSize--)
     Object value = lOIS.readObject();
     put(value);
}