public int hashCode() {
        int result = this.name != null ? this.name.hashCode() : 0;
        result = 31 * result + (this.key != null ? this.key.hashCode() : 0);
       。。。每个属性的hashcode
        return result;
    }
原文:https://www.cnblogs.com/becoding/p/14091963.html