如图就是保留四位(四舍五入)
Double aa = 0.5463785426872534867;
aa = (double) Math.round(aa * 10000) / 10000;
System.out.println(aa);
保留两位就是
Double aa = 0.5463785426872534867;
aa = (double) Math.round(aa * 100) / 100;
System.out.println(aa);
还有一种:
Double aa = 0.5463785426872534867;
aa = (double) Math.round(aa * 10000) / 100;
System.out.println(aa);