Question

I’m trying to use lwuit.io.Storage, it works fine while application is running (I can do crud) but it’s data clears after closing the application.
I’ve considered:

• registering my class with “Util.register(“Car”, Car.class);” in “initVars()” method;
• implementing “Externalizable” interface in “Car” class. // “getObjectId()” method returns “Car”
• calling “Storage.init(“myProjectName”);” in MainMIDlet class
• checking to make sure Storage is initialized properly with “Storage.isInitialized()” in MainMIDlet class

• I’m storing my “car” objects with a Vector, using:

  Car c = new Car("ford", 1918);
  
  Vector v = (Vector) Storage.getInstance().readObject("cars");
  if (v == null) {
      v = new Vector();
  }
  v.addElement(c);
  Storage.getInstance().writeObject("cars", v);
  
  Vector test = (Vector) Storage.getInstance().readObject("cars");
  if (test.lastElement() instanceof Car){
     Car c1 = (Car) test.lastElement();
     System.err.println(c1);
  }
  

• avoiding call “Storage.getInstance().clearStorage();” anywhere in the code!

• “Storage.getInstance().listEntries();” returns one element array containing “cars” String (even after restarting application).

this is my simple “car” class.

any idea what I’m missing / doing wrong here?

thanks in advance

Answer 1

I got it, that was a stupid mistake,

The problem was in implementing Externalizable inteface,
I was calling “Util.writeUTF(name);” in externalize() method, and trying to read it with “stream.readUTF()” in internalize method.

simply replaced “Util.writeUTF(name)” with “stream.writeUTF(name)”.

and it worked out.