Why content of a vector element changes when new element added

Question

in my program, i instantiate 2 Vector objects. one is TV(temporary vector), the other one is V. they all get instances of Class vElement as elements to them(of course, casted to Object first).
Class vElement only cantains an int n, an int[] array.
i create a text file: input.txt
in this text file, there are 2 rows of content:
1 2 3 1001
4 5 6 1002
at the beginning when the program runs, each row of input.txt will be read into a respective instance of vElement, that is, e.g. n = 1001, array = {1, 2, 3}.
and then the 2 instances would be casted as Objects and added to V as elements
then TV starts to get a new vElement from some methods generats 7 8 9 1003
after that, V will add TV's newly-got element as its 3rd element.
what is dramatical is that, the array of V's 1st element { {1, 2, 3} 1001 } will change to be the same as its 2nd one{{4, 5, 7} 1001 } after the 3rd element added to V from TV, yet, 1001 will not change to be 1102.
this problem has challenged and tortured me for quite some days. who can help to conquer it?
thanks a lot more!!

Answer 1

I had the same problem. I believe this is because Vector stores references of everything it is added into it. My problem was solved by creating a new array everytime I had to add an element to Vector.
Instead of:
My_vector.addElement(My_array)
I did:
String[ ] Prov_array = new String[My_array.length];
System.arraycopy(My_array,0,Prov_array, 0,My_array.length);
My_vector.addElement(Prov_array);
Might not be the best solution but it solved the problem.