How to center a string using String.format?

Question

public class Divers {
  public static void main(String args[]){

     String format = \"|%1$-10s|%2$-10s|%3$-20s|\\n\";
     System.out.format(format, \"FirstName\",         


        

Answer 1

Here's an example of how I've handled centering column headers in Java:

public class Test {
    public static void main(String[] args) {
        String[] months = { "January", "February", "March", "April", "May", "June", "July", "August", "September",
                "October", "November", "December" };

        // Find length of longest months value.
        int maxLengthMonth = 0;
        boolean firstValue = true;
        for (String month : months) {
            maxLengthMonth = (firstValue) ? month.length() : Math.max(maxLengthMonth, month.length());
            firstValue = false;
        }

        // Display months in column header row
        for (String month : months) {
            StringBuilder columnHeader = new StringBuilder(month);
            // Add space to front or back of columnHeader
            boolean addAtEnd = true;
            while (columnHeader.length() < maxLengthMonth) {
                if (addAtEnd) {
                    columnHeader.append(" ");
                    addAtEnd = false;
                } else {
                    columnHeader.insert(0, " ");
                    addAtEnd = true;
                }
            }
            // Display column header with two extra leading spaces for each
            // column
            String format = "  %" + Integer.toString(maxLengthMonth) + "s";
            System.out.printf(format, columnHeader);
        }
        System.out.println();

        // Display 10 rows of random numbers
        for (int i = 0; i < 10; i++) {
            for (String month : months) {
                double randomValue = Math.random() * 999999;
                String format = "  %" + Integer.toString(maxLengthMonth) + ".2f";
                System.out.printf(format, randomValue);
            }
            System.out.println();
        }
    }
}