Here is another solution I found.
// returns sum of the column 'col' of array
public static int columnSum(int[][] array, int col) {
int sum = 0;
// for loop traverses through array and adds together only items in a specified column
try {
for (int j = 0; j < array.length; j++) {
if (col < array[j].length)
sum += array[j][col];
}
}
catch (ArrayIndexOutOfBoundsException e){
}
return sum;
} // end columnSum()