Adding whitespace in Java

Question

There is a class trim() to remove white spaces, how about adding/padding?

Note: " " is not the solution.

Answer 1

I think you are talking about padding strings with spaces.

One way to do this is with string format codes.

For example, if you want to pad a string to a certain length with spaces, use something like this:

String padded = String.format("%-20s", str);

In a formatter, % introduces a format sequence. The - means that the string will be left-justified (spaces will be added at the end of the string). The 20 means the resulting string will be 20 characters long. The s is the character string format code, and ends the format sequence.

Answer 2

Use the StringUtils class, it also includes null check

StringUtils.leftPad(String str, int size)
StringUtils.rightPad(String str, int size)

Answer 3

There's a few approaches for this:

1. Create a char array then use Arrays.fill, and finally convert to a String
2. Iterate through a loop adding a space each time
3. Use String.format

Answer 4

String text = "text";
text += new String(" ");