BigDecimal a = new BigDecimal("10.00");  
BigDecimal b = new BigDecimal("10");  
//前提为a、b均不能为null
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");
}