Two-terminal list of JAVA data structure

First, overview:

1, what when the two-terminal linked list:
List of linked lists that hold this to the last point reference

2. Insert from head
To make a judgment on the linked list, set the tail node to the newly added node if it is empty

3, from the tail to insert
If the list is empty, set the header node directly to the newly added node, otherwise set the last node of the tail node as the newly added node

4. Remove from head
Determine if the node has a next node, if not, set the node to null two, specifically implement

/** * @ Description of the linked list of the end-to-end * @ project name Java_datastruct * @ Package Name Com.struct.linklist * @ class name linklist * @au 
    Thor Chenlin * @date June 26, 2010 a.m. 8:00:28 * @version 1.0 * * public class Firstlastlinklist {//Head
    Private Node I;

    Tail private Node last;
        Public Firstlastlinklist () {i = null;
    last = null; /** * Insert Data * @param value/public void Insertfirst (Long value) {Node NewNode = new Nod
        E (value);
        if (A/= null) {last = NewNode;
        }else {//move the A-node down newnode.next = i;
    ///Put the inserted node as the new node, NewNode; /** * Insert Data * @param value/public void Insertlast (Long value) {node NewNode = new Node
        (value);
        if (A/= null) {a = NewNode;
        }else {last.next = NewNode; ///Set the last node to the latest node = newnOde
    public Boolean IsEmpty () {return-= NULL; /** * Delete Header node * @param value * @return/Public node Deletefirst () {if (first = = nul
        L) {throw new RuntimeException ("linked list data does not exist");
        } if (First.next = null) {last = null;
        Node temp = i;
        i = Temp.next;
    return temp;
        Public node Deletebykey (long key) {Node current = i;
        Node last = i;
                while (Current.data!= key) {if (Current.next = null) {System.out.println ("no node Found");
            return null;
            last = current;
        current = Current.next;
            } if (current = = i) {//return deletefirst ();
        Pointing to the next means removing the first first = First.next;
        }else {last.next = Current.next;
    return to current;
     /** * Show all the data*/public void display () {if (A/= null) {//throw new runtimeexception ("list data does not exist");
        Return
        Node current = i;
            while (current!= null) {Current.display ();
        current = Current.next;
    } System.out.println ("---------------"); /** * Lookup Node 1 * @param value * @return/Public node Findbyvalue (Long value) {node C
        urrent = A;
            While (the current!= null) {if (Current.data!= value) {current = Current.next;
            }else {break;
            } if (current = = null) {System.out.println ("not Found");
        return null;
    return to current; /** * Lookup Node 2 * * @param key * @return/Public node Findbykey (long key) {Nod
        e current = A; while (Current.data!= key) {if (Current.next = = null){System.out.println ("not Found");
            return null;
        current = Current.next;
    return to current;
        /** * Find the corresponding value based on index * @param position * @return/public Node findbyposition (int position) {
        Node current = i; 
            Why is position-1, because to use traversal, let current point to the next, so Position-1 's next node is the value for (int i = 0; i < position-1; i++) {
        current = Current.next;
    return to current;
        public static void Main (string[] args) {firstlastlinklist linklist = new Firstlastlinklist ();
        Linklist.insertfirst (21);
        Linklist.insertfirst (22);
        Linklist.insertfirst (23);
        Linklist.insertlast (24);
        Linklist.insertlast (25);
        Linklist.insertlast (26);

        Linklist.insertlast (27);

        Linklist.display ();

        SYSTEM.OUT.PRINTLN ("---find-------------------------------------"); Linklist.findbykey (25).Display ();

        System.out.println ("--delete the-------------------------------------");
        Linklist.deletefirst (). display ();
        Linklist.deletefirst (). display ();
        Linklist.deletefirst (). display ();

        Linklist.deletefirst (). display ();
        System.out.println ("-Delete specified value---------------------------------------");
        Linklist.deletebykey. display ();

        Linklist.deletebykey. display ();
        System.out.println ("----------------------------------------");


    Linklist.display (); }
}