Treeset class assistance

Question

I'm having trouble trying to use the Treeset Class.
Can anyone offer some basic instructions on how to create a priority queue using the Treeset class.

Answer 1

I have given this some thought and the best way I think is to introduce an ordernumber. Each new record that goes into the priority queue is given the current ordernumber which is then incremented. Each record can now be uniquely defined by a combination of the prioritynumber and the ordernumber, like (prioritynumber << 32) | ordernumber. The records will then be sorted by the prioritynumber and within each priority by their ordernumber. Simple code example,
public class Record {   // data record
    public int order;
    public int priority;
    public String data;
    public Record(int o, int p, String d) {
        order = o;
        priority = p;
        data = d;
public void test() {
    Comparator byPriority = new Comparator() {  // defines the order between records
        public int compare(Object o1, Object o2) {
            Record r1 = (Record)o1;
            Record r2 = (Record)o2;
            long l1 =  (((long)r1.priority) << 32) | ((long)r1.order);
            long l2 =  (((long)r2.priority) << 32) | ((long)r2.order);
            int r = 0;
            if (l1<l2)
                r = -1;
            else if (l1>l2)
                r = 1;
            return r;
    TreeSet pQ = new TreeSet(byPriority);   // the priority queue
    int order=0;    // each new record is given a unique order number
    pQ.add(new Record(order++,1,"A"));  // load records
    pQ.add(new Record(order++,2,"B"));
    pQ.add(new Record(order++,5,"C"));
    pQ.add(new Record(order++,1,"D"));
    pQ.add(new Record(order++,1,"E"));
    pQ.add(new Record(order++,0,"F"));
    System.out.println("TreeSet");      // print
    while (!pQ.isEmpty()) {
        Record r = (Record)pQ.first();
        pQ.remove(r);
        System.out.println(r.priority+"/"+r.order+"/"+r.data);
}   // test