我将如何转换System.out.printf("%3s", "");为.print()Java?并且
System.out.printf("%3d\n", (i - startDay));.  
用途String.format(String format, Object... args):
System.out.print(String.format("%3s", ""));
和:
int i = 50;
int startDay = 20;
System.out.print(String.format("%3d\n", (i - startDay)));