⼀
Long是长整型，怎么有⼩数，是double吧
java.text.DecimalFormat df=new java.text.DecimalFormat(\"#.##\"); double d=3.14159;
System.out.println(df.format(d));⼆
java.math.BigDecimal
BigDecimal bd = new BigDecimal(\"3.14159265\"); bd = bd.setScale(2,BigDecimal.ROUND_HALF_UP); 三
class Test1{
public static void main(String[] args){ double ret = convert(3.14159);
System.out.println(ret); }
static double convert(double value){
long l1 = Math.round(value*100); //四舍五⼊
double ret = l1/100.0; //注意：使⽤ 100.0 ⽽不是 100 return ret; } }四
double d = 13.4324; d=((int)(d*100))/100; 我觉得第⼆种⽅法更好．
因篇幅问题不能全部显示，请点此查看更多更全内容