traininfoservice/banedk/TimeoutCache.java

package dk.thoerup.traininfoservice.banedk;

import java.util.concurrent.ConcurrentHashMap;


public class TimeoutCache<K,V> {

        class CacheItem<T> {
                
                public CacheItem(T v) {
                        value = v;
                        lastupdate = System.currentTimeMillis();
                }
                
                public long lastupdate;
                public T value;
        }
        
        private ConcurrentHashMap<K,CacheItem<V>> cache = new ConcurrentHashMap<K,CacheItem<V>>();
        private long timeout;
        
        public TimeoutCache(int timeout) {
                this.timeout = timeout; 
        }
        
        public void put(K k, V v) {
                CacheItem<V> item= new CacheItem<V>(v);
                cache.put(k, item);
        }
        
        public V get(K k) {
                long now = System.currentTimeMillis();
                
                CacheItem<V> item = cache.get(k);
                                
                
                if (item != null) {
                        if ( (item.lastupdate+timeout) < now) { //item too old
                                return null;
                        } else {
                                return item.value; //item still good
                        }
                } else {
                        return null; // no item found
                }
                
        }
        
}
1	package dk.thoerup.traininfoservice.banedk;
2
3	import java.util.concurrent.ConcurrentHashMap;
4
5
6	public class TimeoutCache<K,V> {
7
8	class CacheItem<T> {
9
10	public CacheItem(T v) {
11	value = v;
12	lastupdate = System.currentTimeMillis();
13	}
14
15	public long lastupdate;
16	public T value;
17	}
18
19	private ConcurrentHashMap<K,CacheItem<V>> cache = new ConcurrentHashMap<K,CacheItem<V>>();
20	private long timeout;
21
22	public TimeoutCache(int timeout) {
23	this.timeout = timeout;
24	}
25
26	public void put(K k, V v) {
27	CacheItem<V> item= new CacheItem<V>(v);
28	cache.put(k, item);
29	}
30
31	public V get(K k) {
32	long now = System.currentTimeMillis();
33
34	CacheItem<V> item = cache.get(k);
35
36
37	if (item != null) {
38	if ( (item.lastupdate+timeout) < now) { //item too old
39	return null;
40	} else {
41	return item.value; //item still good
42	}
43	} else {
44	return null; // no item found
45	}
46
47	}
48
49	}