大小_bigdecimal比较

BigDecimal是java.math包中提供的API类
#####代码展示#####

public class Test {
    public static void main(String[] args) throws Exception {
        BigDecimal a = new BigDecimal("0");
        BigDecimal b = new BigDecimal("0.00");
        BigDecimal c = new BigDecimal("0");
        System.out.println(a.equals(b)); //false
        System.out.println(a.equals(c)); //true
        System.out.println(a.compareTo(b)==0); //true
    }
}

####BigDecimal类中的compareTo方法######

public int compareTo(BigDecimal val) {
    if (scale == val.scale) {
        long xs = intCompact;
        long ys = val.intCompact;
        if (xs != INFLATED && ys != INFLATED)
            return xs != ys ? ((xs > ys) ? 1 : -1) : 0;
    }
    int xsign = this.signum();
    int ysign = val.signum();
    if (xsign != ysign)
        return (xsign > ysign) ? 1 : -1;
    if (xsign == 0)
        return 0;
    int cmp = compareMagnitude(val);
    return (xsign > 0) ? cmp : -cmp;
}

#####BigDecimal类中的equals方法#####
@Override
public boolean equals(Object x) {
    if (!(x instanceof BigDecimal))
        return false;
    BigDecimal xDec = (BigDecimal) x;
    if (x == this)
        return true;
    if (scale != xDec.scale)
        return false;
    long s = this.intCompact;
    long xs = xDec.intCompact;
    if (s != INFLATED) {
        if (xs == INFLATED)
            xs = compactValFor(xDec.intVal);
        return xs == s;
    } else if (xs != INFLATED)
        return xs == compactValFor(this.intVal);

    return this.inflated().equals(xDec.inflated());
}

BigDecimal类型的数据比较应使用compareTo方法，不应使用equal方法