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package dk.thoerup.traininfoservice.banedk; |
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import java.util.concurrent.ConcurrentHashMap; |
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public class TimeoutCache<K,V> { |
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class CacheItem<T> { |
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public CacheItem(T v) { |
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value = v; |
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lastupdate = System.currentTimeMillis(); |
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} |
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public long lastupdate; |
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public T value; |
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} |
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private ConcurrentHashMap<K,CacheItem<V>> cache = new ConcurrentHashMap<K,CacheItem<V>>(); |
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private long timeout; |
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public TimeoutCache(int timeout) { |
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this.timeout = timeout; |
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} |
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public void put(K k, V v) { |
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CacheItem<V> item= new CacheItem<V>(v); |
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cache.put(k, item); |
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} |
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public V get(K k) { |
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long now = System.currentTimeMillis(); |
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CacheItem<V> item = cache.get(k); |
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if (item != null) { |
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if ( (item.lastupdate+timeout) < now) { //item too old |
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return null; |
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} else { |
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return item.value; //item still good |
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} |
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} else { |
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return null; // no item found |
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} |
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|
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} |
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} |