BigDecimal 类型计算问题

坑爹啊
BigDecimal 类型 如果传入是String 产生BigDecimal类型的话 精度是按照字符串里面的精度来的 一位小数和两位小数的坑啊 找了一上午。

package com.ccbtrust.tm.ac.familytrust.distribution;

import java.math.BigDecimal;

public class Testjjj {
	public static void main(String[] args) {
		String allAmount1=\"25378238.40\";
		String allAmount2=\"25378238.4\";
		BigDecimal bigDecimal = new BigDecimal(allAmount1);
		BigDecimal bigDecimal2 = new BigDecimal(allAmount2);
		System.out.println(bigDecimal);
		System.out.println(bigDecimal2);
		
		BigDecimal allShare1 = new BigDecimal(839800000);
		BigDecimal currentShare1 = new BigDecimal(89800000 );
		
			
		BigDecimal c1 = calBenefitAmtByAct(allAmount1, allShare1, currentShare1);
		System.out.println(c1.toString());
		BigDecimal c2 = calBenefitAmtByAct(allAmount2, allShare1, currentShare1);
		System.out.println(c2.toString());
		BigDecimal c3 = calBenefitAmtByAct2(allAmount1, allShare1, currentShare1);
		System.out.println(c3.toString());
		BigDecimal c4 = calBenefitAmtByAct2(allAmount2, allShare1, currentShare1);
		System.out.println(c4.toString());
		
	}
	public static BigDecimal calBenefitAmtByAct(String allAmount, BigDecimal allShare,BigDecimal currentShare) {//按实际利润计算
		// TODO Auto-generated method stub
		return new BigDecimal(allAmount).multiply(currentShare).divide(allShare,2,BigDecimal.ROUND_HALF_UP);
	}
	public static BigDecimal calBenefitAmtByAct2(String allAmount, BigDecimal allShare,BigDecimal currentShare) {//按实际利润计算
		// TODO Auto-generated method stub
		return new BigDecimal(allAmount).multiply(currentShare).divide(allShare,1);
	}

}