How to center string output using printf() and variable width? [java]

Question

I'm creating an output in Java using printf() to create table headers. One of the columns needs variable width.

Basically it should look like this:

//two coords
Trial    Column Heading
1        (20,30)(30,20)
//three coords
Trial        Column Heading
1        (20,40)(50,10)(90,30)

I tried to use:

int spacing = numCoords * 7; //size of column
printf("Trial    %*^s", column, "Column Heading");

But I keep getting output errors when I try to use * or ^ in the conversion statement.

Does anyone have any idea what the correct formatting string should be?

Answer 1

In Java, use System.out.println()

According to your requirements, You should be using something like,

System.out.println("Trial"+getSpacer(spacing)+"Column Heading");

Here getSpacer(int spaces) will return you a String with that many number of spaces you want.

Answer 2

Java does not support the "*" format specifier. Instead, insert the width directly into the format string:

int spacing = numCoords * 7; //size of column
System.out.printf("Trial    %" + spacing + "s", "Column Heading");

Answer 3

Use StringUtils.center from the Commons Lang library:

StringUtils.center(column, "Column Heading".length());