Variable widths in Java's String.format method

This works:

int depth = 5;
String str= "Hello"+ String.format("%"+depth+"s"," ") + "world" + "\n";
System.out.println(str);

It prints 5 while spaces in between.

Hello     World.

Please check you code and make sure that depth is assigned with a valid int value. Most likely that (invalid value in depth) is the problem.