java - 在java中对ArrayList与日期进行排序

Question

我正在尝试对 ArrayList 与 termDate 进行排序ArrayList 包含名字、姓氏、电子邮件、开始日期、学期日期

日期可以为空或为 null。我必须进行相应的比较，并将所有空/空日期值放在最后。

Collections.sort(usersList, new Comparator<User>() {
                public int compare(User o1, User o2) {
                    if(o1.getTermDate() == null && o2.getTermDate() == null)
                        return 0; //They are both null, both equal
                    if(o1.getTermDate() == null && o2.getTermDate() != null)
                        return -1; // The first is null and the second is not, return the first as lower than the second
                    if(o1.getTermDate() != null && o2.getTermDate() == null)
                        return 1; //The first is not null and the second is, return the first as higher than the second
                    else
                        return o1.getTermDate().compare(o2.getTermDate()); //Return the actual comparison
                }
            });

它不是编译比较方法。

请指导。

Answer 1

您应该将 return o1.getTermDate().compare(o2.getTermDate()); 更改为 return o1.getTermDate().compareTo(o2.getTermDate()); 因为类 java.util.Date; 没有名为 compare 的方法。