public class TestDemo {
      public static void main(String[] args) {
          String format = new DecimalFormat("##0.#######").format(10.000001);         System.out.println(format);         DecimalFormat f = new DecimalFormat("#,##0.00");         f.setRoundingMode(RoundingMode.HALF_UP);         String format1 = f.format(1.126);         System.out.println(format1);     } } output: 1.12

DecimalFormat f = new DecimalFormat("#,##0.00");

f.setRoundingMode(RoundingMode.HALF_UP);

double d = 1.125;

System.out.println(f.format(d)); // 输出 1.12

d = 1.135;

System.out.println(f.format(d)); // 输出 1.14

 

 

public static float div(int v1, int v2, int scale) { 

  if (v2 != 0) { 

    BigDecimal b1 = new BigDecimal(Double.toString(v1)); 

    BigDecimal b2 = new BigDecimal(Double.toString(v2)); 

    return b1.divid(b2,scale,BigDecimal.ROUND_HALF_UP).doubleValue(); 

  } else { 

      return 0; 

  } 

} 

//scale表示保留几位小数