What you can do with a LinkedHashMap. : LinkedHashMap « Collections « Java Tutorial

1. Java Tutorial
2. Collections
3. LinkedHashMap

import java.util.LinkedHashMap;

public class MainClass {

  public static void main(String[] args) {
    LinkedHashMap linkedMap = new LinkedHashMap();
    for (int i = 0; i < 10; i++) {
      linkedMap.put(i, i);
    }

    System.out.println(linkedMap);
    // Least-recently used order:
    linkedMap = new LinkedHashMap(16, 0.75f, true);

    for (int i = 0; i < 10; i++) {
      linkedMap.put(i, i);
    }
    System.out.println(linkedMap);
    for (int i = 0; i < 7; i++)
      // Cause accesses:
      System.out.println(linkedMap.get(i));
    System.out.println(linkedMap);
  }
}

{0=0, 1=1, 2=2, 3=3, 4=4, 5=5, 6=6, 7=7, 8=8, 9=9}
{0=0, 1=1, 2=2, 3=3, 4=4, 5=5, 6=6, 7=7, 8=8, 9=9}
0
1
2
3
4
5
6
{7=7, 8=8, 9=9, 0=0, 1=1, 2=2, 3=3, 4=4, 5=5, 6=6}