summing column by column in java

I would use a try-with-resources to clean up my Scanner using the File. Also, you could construct a Scanner around the line of input to get your int columns (that doesn't need to be closed because String(s) aren't closable anyway). Something like,

try (Scanner sc = new Scanner(new File("patch"))) {
    while (sc.hasNextLine()) {
        String line = sc.nextLine();
        Scanner row = new Scanner(line);
        long sum = 0;
        int count = 0;
        while (row.hasNextInt()) {
            int val = row.nextInt();
            if (count == 0) {
                System.out.print(val);
            } else {
                System.out.printf(" + %d", val);
            }
            sum += val;
            count++;
        }
        System.out.println(" = " + sum);
    }
} catch (IOException e) {
    e.printStackTrace();
}

As the Scanner(String) Constructor Javadoc documents

Constructs a new Scanner that produces values scanned from the specified string.

Edit To sum the columns is a little trickier, but you could read everything into a multidimensional List<List<Integer>> like

try (Scanner sc = new Scanner(new File("patch"))) {
    List<List<Integer>> rows = new ArrayList<>();
    int colCount = 0;
    while (sc.hasNextLine()) {
        List<Integer> al = new ArrayList<>();
        String line = sc.nextLine();
        Scanner row = new Scanner(line);
        colCount = 0;
        while (row.hasNextInt()) {
            colCount++;
            int val = row.nextInt();
            al.add(val);
        }
        rows.add(al);
    }
    for (int i = 0; i < colCount; i++) {
        long sum = 0;
        for (List<Integer> row : rows) {
            sum += row.get(i);
        }
        if (i != 0) {
            System.out.print("\t");
        }
        System.out.print(sum);
    }
    System.out.println();
} catch (IOException e) {
    e.printStackTrace();
}

Edit 2 For efficiencies sake, you might prefer to use a Map like

try (Scanner sc = new Scanner(new File("patch"))) {
    Map<Integer, Integer> cols = new HashMap<>();
    while (sc.hasNextLine()) {
        String line = sc.nextLine();
        Scanner row = new Scanner(line);
        int colCount = 0;
        while (row.hasNextInt()) {
            int val = row.nextInt();
            if (cols.containsKey(colCount)) {
                val += cols.get(colCount);
            }
            cols.put(colCount, val);
            colCount++;
        }
    }
    for (int i : cols.values()) {
        System.out.printf("%d\t", i);
    }
    System.out.println();
} catch (IOException e) {
    e.printStackTrace();
}