JAVA 保留两位小数的四种方法

1. import java.math.BigDecimal;
2. import java.text.DecimalFormat;
3. import java.text.NumberFormat;
4. publicclass format {
5. double f = 111231.5585;
6. publicvoid m1() {
7. BigDecimal bg = new BigDecimal(f);
8. double f1 = bg.setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue();
9. System.out.println(f1);
10. }
11. /**
12. * DecimalFormat转换最简便
13. */
14. publicvoid m2() {
15. DecimalFormat df = new DecimalFormat("#.00");
16. System.out.println(df.format(f));
17. }
18. /**
19. * String.format打印最简便
20. */
21. publicvoid m3() {
22. System.out.println(String.format("%.2f", f));
23. }
24. publicvoid m4() {
25. NumberFormat nf = NumberFormat.getNumberInstance();
26. nf.setMaximumFractionDigits(2);
27. System.out.println(nf.format(f));
28. }
29. public staticvoid main(String[] args) {
30. format f = new format();
31. f.m1();
32. f.m2();
33. f.m3();
34. f.m4();
35. }
36. }

结果：

111231.56

111231.56

111231.56

111,231.56