Casting Object using imported class

Question

The problem im having is when trying to de-serialize an obejct. the class that defines the object is stored in a different package and this code works fine when i move the class into the same package.
Im getting a ClassNotFoundException on the line with the >>
Any thoughts on why i cant cast using a class from another package?
     private void loadTest(){
          try {
               FileInputStream fi = new FileInputStream("./Tests/"+plantComboBox.getSelectedItem()+"/"+mode+"/"+testComboBox.getSelectedItem()+"/"+testComboBox.getSelectedItem()+".test");
               ObjectInputStream oi = new ObjectInputStream(fi);
               >>test = (Test)oi.readObject();
               //test.printTest();
               oi.close();
          } catch (Exception er) {
               er.printStackTrace();
     }

Answer 1

Yeah i figured it out. The object that was serialized was made in a different project and was contained in a package called "main".
In my other project When i was running that method with the "Test" class in the same package as the method, it was, coincidently in the "main" package and when i moved it to my "test" package and the object was de-serialized it was being re-initialized with its package as "main" and throwing the error.