java中如何将double转换为string java double转换成string

Double d1=12345678.00;
        Double d2=12345678.99;
        NumberFormat nf = NumberFormat.getInstance();
        nf.setGroupingUsed(false);//避免长数字带逗号
        String s1 = nf.format(d1);
        String s2 = nf.format(d2);
        System.out.println(s1);
        System.out.println(s2);