java精度计算代码 java指定精确小数位

public class App2 { public static void main(String[] args) { String val = checkNumber("10.1234155", 2, 6).toString(); System.out.println(val); } public static BigDecimal checkNumber(String number, int min, int max) { // 初始化为max位小数 DecimalFormat df = new DecimalFormat(getMaxStr(max)); String num = df.format(Double.parseDouble(number)); BigDecimal bd = new BigDecimal(num); String val = bd.toString(); val = val.replaceAll("^(0+)", ""); val = val.replaceAll("(0+)$", ""); int idx = val.indexOf("."); int len = val.substring(idx + 1).length(); if (len < min) {  if (len == 0 && idx == 0) {  bd = new BigDecimal("0.00");  } else {  bd = new BigDecimal(val).setScale(2);  } } else {  bd = new BigDecimal(val).setScale(len); } return bd; } public static String getMaxStr(int max) { String val = "0."; for (int i = 0; i < max; i++) {  val += "0"; } return val; }}