[java] how to write an array to a file Java

I have been trying to write an array to a file. I know how to write integers or String to a file but to bring an array confuses me. I am using this right now:

public static void write (String file, int[]x) throws IOException{
    BufferedWriter outputWriter = null;
    outputWriter = new BufferedWriter(new FileWriter(filename));
    outputWriter.write("hi");// Here I know i cant just write x[0] or anything. Do i need 
                             //to loop in order to write the array?
    outputWriter.newLine();
    outputWriter.flush();  
    outputWriter.close();  



}

If you're okay with Apache commons lib

outputWriter.write(ArrayUtils.join(array, ","));

private static void saveArrayToFile(String fileName, int[] array) throws IOException {
    Files.write( // write to file
        Paths.get(fileName), // get path from file
        Collections.singleton(Arrays.toString(array)), // transform array to collection using singleton
        Charset.forName("UTF-8") // formatting
    );
}

You can use the ObjectOutputStream class to write objects to an underlying stream.

outputStream = new ObjectOutputStream(new FileOutputStream(filename));
outputStream.writeObject(x);

And read the Object back like -

inputStream = new ObjectInputStream(new FileInputStream(filename));
x = (int[])inputStream.readObject()

If the result is for humans to read and the elements of the array have a proper toString() defined...

outputString.write(Arrays.toString(array));

Just loop over the elements in your array.

Ex:

for(int i=0; numOfElements > i; i++)
{
outputWriter.write(array[i]);
}
//finish up down here