How to display a number with always 2 decimal poin

问题:

I am using BigDecimal to get some price values. Requirement is something like this, what ever the value we fetch from database, the displayed valued should have 2 decimal points.

Eg:

fetched value is 1 - should be displayed as 1.00
fetched value is 1.7823 - should be displayed as 1.78

I am using setScale(2, BigDecimal.ROUND_HALF_UP) but still some places, if the data from DB is a whole number then the same is being displayed !!

I mean if the value is 0 from DB its displayed as 0 only. I want that to be displayed as 0.00

Thanks

回答1:

BigDecimal is immutable, any operation on it including setScale(2, BigDecimal.ROUND_HALF_UP) produces a new BigDecimal. Correct code should be

        BigDecimal bd = new BigDecimal(1);
//      bd.setScale(2, BigDecimal.ROUND_HALF_UP);   bd.setScale does not change bd
        bd = bd.setScale(2, BigDecimal.ROUND_HALF_UP);
        System.out.println(bd);

output

1.00

回答2:

you can use the round up format

BigDecimal bd = new BigDecimal(2.22222);
System.out.println(bd.setScale(2,BigDecimal.ROUND_UP));

Hope this help you.

回答3:

To format numbers in JAVA you can use:

 System.out.printf("%1$.2f", d);

where d is your variable or number

or

 DecimalFormat f = new DecimalFormat("##.00");  // this will helps you to always keeps in two decimal places
 System.out.println(f.format(d)); 

回答4:

You need to use something like NumberFormat with appropriate locale to format

NumberFormat.getCurrencyInstance().format(bigDecimal);

回答5:

BigDecimal.setScale would work.