Java serialization of multidimensional array

Question

Hey everyone,

Is it possible to make a 2D array in java serializable?

If not, i am looking to "translate" a 3x3 2D array into a Vector of Vectors.

I have been playing around with vectors, and I am still unsure of how to represent that. Can anyone help me?

Thanks!

Answer 1

Arrays in Java are serializable - thus Arrays of Arrays are serializable too.

The objects they contain may not be, though, so check that the array's content is serializable - if not, make it so.

Here's an example, using arrays of ints.

public static void main(String[] args) {

 int[][] twoD = new int[][] { new int[] { 1, 2 },
   new int[] { 3, 4 } };

 int[][] newTwoD = null; // will deserialize to this

 System.out.println("Before serialization");
 for (int[] arr : twoD) {
  for (int val : arr) {
   System.out.println(val);
  }
 }

 try {
  FileOutputStream fos = new FileOutputStream("test.dat");
  ObjectOutputStream oos = new ObjectOutputStream(fos);
  oos.writeObject(twoD);

  FileInputStream fis = new FileInputStream("test.dat");
  ObjectInputStream iis = new ObjectInputStream(fis);
  newTwoD = (int[][]) iis.readObject();

 } catch (Exception e) {

 }

 System.out.println("After serialization");
 for (int[] arr : newTwoD) {
  for (int val : arr) {
   System.out.println(val);
  }
 }
}

Output:

Before serialization
1
2
3
4
After serialization
1
2
3
4