如何对用户定义的LinkedList进行排序

Question

我一直试图对链表进行排序，但一切都无济于事。我的格式是：

1. 按firstname排序，
2. age，
3. 姓氏以外的任何其他号码。

我已在下面发布了我的代码段。但每次我运行程序时，都会收到错误说 "This file cannot be accessed because another process is using the file"
我将感谢您的贡献。我的所有其他代码运行完美没有问题。我非常肯定。排序是我唯一的问题。非常感谢

public void sort(int order) {

     switch(order){
     case 1:
            Node tempVar;
            for (Node cur = head; cur != null; cur = cur.next) {

                for (Node cux = head; cux != null; cux = cux.next) {

                     if(compareByFN(cur, cux)==1)
                        {
                               tempVar = cux;
                               cux= cur;
                               cur = tempVar;
                        }
                }

            }
         break;
     case 2:
            Node tempVar3;
            for (Node cur = head; cur != null; cur = cur.next) {

                for (Node cux = head; cux != null; cux = cux.next) {

                     if(compareByAge(cur, cux)==1)
                        {
                               tempVar3 = cux;
                               cux= cur;
                               cur = tempVar3;
                        }
                }

            }
         break;
     default:
            Node tempVar2;
            for (Node cur = head; cur != null; cur = cur.next) {

                for (Node cux = head; cux != null; cux = cux.next) {

                     if(compareByLN(cur, cux)==1)
                        {
                               tempVar2 = cux;
                               cux= cur;
                               cur = tempVar2;
                        }
                }

            }
         break;
     }

 }

 private  int compareNulls(Node event1, Node event2)
    {
        if (event1 == null && event2 == null)
            return 0;
        else if (event1 == null )
        {
            return -1;
        }
        else 
        {
            return 1;
        }
    }

 private  int compareByFN(Node event1, Node event2) {
        int comp = event1.data.getFn().compareTo(event2.data.getFn());
        if (event1 == null || event2 == null)
            return compareNulls(event1, event2);
        else if (comp==0) return 0;
        else if (comp<0) return -1;
        else return 1;
    }

    private  int compareByLN(Node event1, Node event2) {
        int comp = event1.data.getLn().compareTo(event2.data.getLn());
        if (event1 == null || event2 == null)
            return compareNulls(event1, event2);
        else if (comp==0) return 0;
        else if (comp<0) return -1;
        else return 1;
    }


    private int compareByAge(Node event1, Node event2) {
        return compare(event1.data.getDob(), event2.data.getDob());
    }

    private int compare(Date date1, Date date2) {
        int result;

        if (date1 == null) {


            if (date2 == null)

                result = 0;
            else

                result = -1;            
        }
        else if (date2 == null)

            result = 1;
        else {
            if (date1.getYear() == date2.getYear()) {

                if (date1.getMonth() == date2.getMonth()) {


                    if (date1.getDay() == date2.getDay())


                        result = 0;
                    else if (date1.getDay() < date2.getDay())

                        result = -1;
                    else

                        result = 1;
                }
                else if (date1.getMonth() < date2.getMonth())

                    result = -1;
                else

                    result = 1;
            }
            else if (date1.getYear() < date2.getYear())

                result = -1;
            else

                result = 1;
        }

        return result;
    }