01.import java.math.BigDecimal;
02.import java.text.DecimalFormat;
03.import java.text.NumberFormat;
04.
05.public class format {
06. double f = 111231.5585;
07. public void m1() {
08. BigDecimal bg = new BigDecimal(f);
09. double f1 = bg.setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue();
10. System.out.println(f1);
11. }
12. /**
13. * DecimalFormat转换最简便
14. */
15. public void m2() {
16. DecimalFormat df = new DecimalFormat("#.00");
17. System.out.println(df.format(f));
18. }
19. /**
20. * String.format打印最简便
21. */
22. public void m3() {
23. System.out.println(String.format("%.2f", f));
24. }
25. public void m4() {
26. NumberFormat nf = NumberFormat.getNumberInstance();
27. nf.setMaximumFractionDigits(2);
28. System.out.println(nf.format(f));
29. }
30. public static void main(String[] args) {
31. format f = new format();
32. f.m1();
33. f.m2();
34. f.m3();
35. f.m4();
36. }
37.}