一个最简单的LRUCache实现 (JAVA)

流程图：

1. 代码

 import java.util.ArrayList;

 public class LRUCache {
     private int cacheMaxSize = 0;
     private ArrayList<Integer> pages = null; // Interger means page id

     public LRUCache(int cacheMaxSize) {
         this.cacheMaxSize = cacheMaxSize;
         pages = new ArrayList<Integer>();
     }

     public void add(Integer p) {
         if (pages.contains(p)) {
             pages.remove(p);
             pages.add(p);
         } else if (pages.size() == cacheMaxSize) {
             pages.remove(0);
             pages.add(p);
         } else {
             pages.add(p);
         }     }
 }

2. 测试的代码

import java.util.ArrayList;
import java.util.Scanner;

import xqy.been.LRUCache;

public class LRU {
    private Scanner sc;
    private LRUCache lc = null;
    private ArrayList<Integer> pages = null;

    public LRU() {
        sc = new Scanner(System.in);
        pages = new ArrayList<Integer>();

        init();
        op();
    }

    private void init() {
        int key = -2;

        System.out.print("<LRU> 请输入物理块个数：");
        lc = new LRUCache(sc.nextInt());

        System.out.println("<LRU> 请按顺序输入页号(exit: -1): ");
        while (key != -1) {
            key = sc.nextInt();

            if (key > 0) {
                pages.add(key);
            }
        }
    }

    private void op() {
        for (int i = 0; i < pages.size(); i++) {
            lc.add(pages.get(i));
        }
    }

    public static void main(String[] args) {
        new LRU();
    }
}