더블링크드 리스트 구현하기

package java8;
 
 
 
public class Node {
 
 
 
 public Node next;
 
 public Node prev;
 
 private String value;
 
 
 
 public Node(String value) {
 
  this.value = value;
 
 }
 
 
 
 public Node() {
 
  
 
 }
 
 
 
 public String getValue() {
 
  return value;
 
 }
 
 
 
 public void setValue(String value) {
 
  this.value = value;
 
 }
 
}
 
 
 
 
 
 
 
 
package java8;
 
 
 
import java.util.Scanner;
 
 
 
public class MainClass {
 
 public static void main(String args[]) {
 
  System.out.print("값을 입력하세요. : ");
 
  Scanner in = new Scanner(System.in);
 
  Node parentNode = new Node(in.next());
 
  Node curr = parentNode;
 
  StringBuilder str = new StringBuilder();
 
 
 
  while (true) {
 
   System.out.print("값을 입력하세요. : ");
 
   String input = in.next();
 
   if (input.equals("-1")) {
 
    break;
 
   }
 
   Node node = new Node(input);
 
   curr.next = node;
 
   node.prev = curr;
 
   curr = node;
 
  }
 
 
 
  curr = parentNode;
 
 
 
  while (true) {
 
   System.out.print(curr.getValue() + " ");
 
   if (curr.next == null)
 
    break;
 
   curr = curr.next;
 
  }
 
  System.out.println();
 
 
 
  while (curr != null) {
 
   System.out.print(curr.getValue() + " ");
 
   if (curr.prev == null)
 
    break;
 
   curr = curr.prev;
 
  }
 
 }
 
}