Write to file - Recieving Null Pointer Exception

Question

I'm receiving a null point exception when attempting to write to a file. The error is coming from the line below.

outputWriter.write(animals[p].toString());

Im assuming its because im passing null with the array. The array is previously created and is filled with objects with different values.

Here is my write file:

public void writeAquatic()
{
    try
    {

        BufferedWriter outputWriter;
        String fileName = "Output.txt";
        outputWriter = new BufferedWriter(new FileWriter(fileName));
        for(int p = 0; p < animals.length; p++)
        {
            outputWriter.write(animals[p].toString());
            outputWriter.newLine();
        }
        outputWriter.flush();
        outputWriter.close();
    }
    catch(IOException ex)
    {
        System.out.println(ex.getMessage());
    }
    catch(NullPointerException e)
    {
        System.out.println("Null Pointer Exception");
    }
}