Java's several ways to retain several decimal places and add thousands separator __java

Package decimal;
Import Java.math.BigDecimal;
Import Java.text.DecimalFormat;

Import Java.text.NumberFormat; /** * Java several ways to retain several decimal places and add thousands separator * <p>ClassName:TestDecimal</p> * <p>description: Keep a few decimal places </p> * <p>Author:Administrator</p> * <p>date:2017 Year April 26 </p> * * Public class Testdecimal {public
        static void Main (string[] args) {//mode a small number of less than 4 people are several, more than 4 people leave only 4-digit double DD1 = 911.911;
        Double dd2 = 911.911911;
        DecimalFormat df = new DecimalFormat ("#.0000");
        DD1 = double.parsedouble (Df.format (DD1));
        DD2 = double.parsedouble (Df.format (DD2));
        System.out.println (DD1);
        System.out.println (DD2);
        System.out.println ("////////");
        The way two decimal places less than 4 people with 0 complement, more than 4 people leave only 4 digits double ds1 = 911.911;
        Double ds2 = 911.911911;
        String RESULT1 = String.Format ("%.4f", DS1);
        String result2 = String.Format ("%.4f", DS2);
 System.out.println (RESULT1);       System.out.println (RESULT2);
        System.out.println ("////////");
        The mode of the three decimal places of less than 4 people are several, more than 4 people left only 4, and rounded double db1 = 911.911;
        Double DB2 = 911.91186;
        BigDecimal bd1 = new BigDecimal (DB1);
        BigDecimal bd2 = new BigDecimal (DB2);
        DB1 = Bd1.setscale (4, bigdecimal.round_half_up). Doublevalue ();
        DB2 = Bd2.setscale (4, bigdecimal.round_half_up). Doublevalue ();
        System.out.println (DB1);
        SYSTEM.OUT.PRINTLN (DB2);
        System.out.println ("////////");
        Mode four number of decimal places less than 4 people are several, more than 4 people left only 4 double dn1 = 911.911;
        Double dn2 = 911.911911;
        NumberFormat NF = numberformat.getnumberinstance ();
        Nf.setmaximumfractiondigits (4);
        String str1 = Nf.format (DN1);
        String str2 = Nf.format (DN2);
        System.out.println (STR1);
        System.out.println (STR2);
        System.out.println ("////////");
        Add thousand separator double n = 1000.3; DecimalFormat DF2 = new DecimalforMat ("#,###.00");
        String m = Df2.format (n);
    System.out.print (m); }
}