How do I properly align using String.format in Java?

Question

Let\'s say I have a couple variable and I want to format them so they\'re all aligned, but the variables are different lengths. For example:

String a = \"abc         


        

Answer 1

You can find the longest String, and then use Apache commons-lang StringUtils to leftPad both of your String(s). Something like,

int len = Math.max(a.length(), b.length()) + 2;
a = StringUtils.leftPad(a, len);
b = StringUtils.leftPad(b, len);

Or, if you can't use StringUtils - you could implement leftPad. First a method to generate String of whitespace. Something like,

private static String genString(int len) {
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < len; i++) {
        sb.append(' ');
    }
    return sb.toString();
}

Then use it to implement leftPad - like,

private static String leftPad(String in, int len) {
    return new StringBuilder(in) //
            .append(genString(len - in.length() - 1)).toString();
}

And, I tested it like,

int len = Math.max(a.length(), b.length()) + 2;
System.out.format("%s %.2f%n", leftPad(a, len), price);
System.out.format("%s %.2f%n", leftPad(b, len), price);

Which outputs (as I think you wanted)

abcdef      4.56
abcdefhijk  4.56