一个LinkedList的简单体现(用户缓存手机通话记录)
public class RequestCache {
// TODO cache lifeTime
// 限制最多缓存10条
private static int CACHE_LIMIT = 10;
@SuppressWarnings("unchecked")
private LinkedList history;
private Hashtable<String, String> cache;
@SuppressWarnings("unchecked")
public RequestCache(){
history = new LinkedList();
cache = new Hashtable<String, String>();
}
@SuppressWarnings("unchecked")
public void put(String url, String data){
history.add(url);
// too much in the cache, we need to clear something
//如果缓存中超过规定的条数,需要删除一部分
//这里需要注意一下“链表是如何删除数据的”:pool()表示获取并移除此列表的头
if(history.size() > CACHE_LIMIT){
String old_url = (String) history.poll();
cache.remove(old_url);
}
cache.put(url, data);
}
public String get(String url){
return cache.get(url);
}
}