userlinklist.java

网络聊天程序 有客户端和服务器端 客户端之间通讯

public class UserLinkList {
	Node root;
	Node pointer;
	int count;

	public UserLinkList(){
		root = new Node();
		root.next = null;
		pointer = null;
		count = 0;
	}

	public void addUser(Node n){
		pointer = root;

		while(pointer.next != null){
			pointer = pointer.next;
		}

		pointer.next = n;
		n.next = null;
		count++;

	}
	public void delUser(Node n){
		pointer = root;

		while(pointer.next != null){
			if(pointer.next == n){
				pointer.next = n.next;
				count --;

				break;
			}

			pointer = pointer.next;
		}
	}
	public int getCount(){
		return count;
	}
	public Node findUser(String username){
		if(count == 0) return null;

		pointer = root;

		while(pointer.next != null){
			pointer = pointer.next;

			if(pointer.username.equalsIgnoreCase(username)){
				return pointer;
			}
		}

		return null;
	}
	public Node findUser(int index){
		if(count == 0) {
			return null;
		}

		if(index <  0) {
			return null;
		}

		pointer = root;

		int i = 0;
		while(i < index + 1){
			if(pointer.next != null){
				pointer = pointer.next;
			}
			else{
				return null;
			}

			i++;
		}

		return pointer;
	}
}