LinkedHashMap简单实现LRU

public class LRULinkedHashMap extends LinkedHashMap{

    //缓冲容量
    private int capacity;

    public LRULinkedHashMap(int capacity){
        super(16,0.75f,true);
        this.capacity = capacity;
    }

	//重写removeEldestEntry 返回值代表是否需要删除最老的节点的判断
    @Override
    protected boolean removeEldestEntry(Map.Entry eldest) {
        boolean sign = size() > capacity;
        if(sign){
            System.out.println("要删除地是："+eldest);
        }
        return sign;
    }
}

public static void main(String[] args) {
        LRULinkedHashMap map = new LRULinkedHashMap(4);
        map.put("111",111);
        map.put("222",222);
        map.put("333",333);
        map.put("444",444);
        map.put("555",555);

        Iterator> iterator = map.entrySet().iterator();
        while (iterator.hasNext()){
            Map.Entry entry = iterator.next();
            System.out.println(entry.getKey()+ "=="+ entry.getValue());

        }
    }

要删除地是：111=111
222==222
333==333
444==444
555==555