@Test
public void cs1(){

    BigDecimal a = BigDecimal.valueOf(-1);
    BigDecimal b = BigDecimal.ZERO;

    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");
    }

}