BigDecimal比较大小

if(a.compareTo(b) == -1){ System.out.println("a小于b"); }

if(a.compareTo(b) == 0){ System.out.println("a等于b"); }

if(a.compareTo(b) == 1){ System.out.println("a大于b"); }

if(a.compareTo(b) > -1){ System.out.println("a大于等于b"); }

if(a.compareTo(b) < 1){ System.out.println("a小于等于b"); }

//注意：A、B均不能为Null