BigDecimal比较大小
这个类是java里精确计算的类，下面说一下两个BigDecimal对象大小，相等的判断
1 比较对象是否相等
一般的对象用equals，但是BigDecimal比较特殊，举个例子：
BigDecimal a=BigDecimal.valueOf(1.0);
BigDecimal b=BigDecimal.valueOf(1.000);
在现实中这两个数字是相等的，但是问题来来了
a.equals(b)结果是false;怎么不相等了呢？这个问题我也不知道
解决办法：
if(a.compareTo(b)==0)结果是true
public int compareTo(BigDecimal val)
Compares this BigDecimal with the specified BigDecimal.
Two BigDecimal objects that are equal in value but have a different
scale (like 2.0 and 2.00) are considered equal by this method.
This method is provided in preference to individual methods for each of
the six boolean comparison operators (<, ==, >, >=, !=, <=).
The suggested idiom for performing these comparisons is: (x.compareTo(y) <op> 0), where <op> is one of the six comparison operators.
Specified by:
compareTo in interface Comparable<BigDecimal>
Parameters:
val - BigDecimal to which this BigDecimal is to be compared.
Returns:
-1, 0, or 1 as this BigDecimal is numerically less than, equal to, or greater than val.
简单翻译：
结果是-1 小于
0 等于
1 大于
本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/ylh2003/archive/2006/12/04/1429337.aspx
以上是在网上找到文章。
if(a.compareTo(b) == -1){
//a<b
}
if(a.compareTo(b)==0){
//a=b;
}
if(a.compareTo(b)==1){
//a>b;
}