使用LinkedHashMap来实现LRU算法
程序员文章站
2022-06-19 12:14:00
LRU算法:即淘汰最近最少未使用的请求算法LinkedHashMap中除了具有链表和HashMap的特征之外,还具有实现LRU算法的一些特性。从其源码注解中可以得知:This kind of map is well-suited to building LRU caches. Invoking the {@code put}, {@code putIfAbsent}, {@code get}, {@code getOrDefault}, {@code compute}, {@code compute...
LRU算法:即淘汰最近最少未使用的请求算法
LinkedHashMap中除了具有链表和HashMap的特征之外,还具有实现LRU算法的一些特性。
从其源码注解中可以得知:
This kind of map is well-suited to building LRU caches. Invoking the {@code put}, {@code putIfAbsent}, {@code get}, {@code getOrDefault}, {@code compute}, {@code computeIfAbsent}, {@code computeIfPresent}, or {@code merge} methods results in an access to the corresponding entry (assuming it exists after the invocation completes).
下面是实现的代码:
import java.util.LinkedHashMap;
import java.util.Map;
/**
* @author yupeiyang
*
* 实现LRU算法
*/
public class LruDemo1<K,V> extends LinkedHashMap<K,V> {
private int capacity; //缓存空间
public LruDemo1(int capacity){
//accessOrder : true表示访问顺序、false表示插入顺序
super(capacity,0.75f,true);
//super(capacity,0.75f,false);
this.capacity = capacity;
}
@Override
protected boolean removeEldestEntry(Map.Entry<K, V> eldest) {
return super.size() > capacity;
}
public static void main(String[] args) {
LruDemo1 lruDemo1 = new LruDemo1(3);
lruDemo1.put(4,"e");
lruDemo1.put(3,"c");
lruDemo1.put(1,"a");
lruDemo1.put(5,"f");
lruDemo1.put(2,"b");
System.out.println(lruDemo1.keySet());
System.out.println(lruDemo1.values());
lruDemo1.put(6,"g");
System.out.println(lruDemo1.keySet());
System.out.println(lruDemo1.values());
}
}
执行结果:
本文地址:https://blog.csdn.net/weixin_43157935/article/details/112003697
上一篇: 如何在制造业中运作数据挖掘技术?
下一篇: 发现互联网数据中的知识与情报