, new Comparator<ContactsBaseBean>()

public abstract class ContactsBaseBean implements Searchable, BaseStickyBean,
Comparable<ContactsBaseBean>, Parcelable 

Collections.sort(temp, new Comparator<ContactsBaseBean>() {

@Override
public int compare(ContactsBaseBean lhs, ContactsBaseBean rhs) {
return (int) (rhs.getLastChatTime() - lhs.getLastChatTime());
}

});

@Override
public int compareTo(ContactsBaseBean another) {
// TODO Auto-generated method stub
// if (TextUtils.isEmpty(real_name)
// || TextUtils.isEmpty(another.real_name)) {
// return -1;
// }
String c1 = getStickyItem();
if (c1.equals("#")) {
return -1;
}
String c2 = another.getStickyItem();
if (c2.equals("#")) {
return 1;
}
return c1.compareTo(c2);
}