traininfoservice/banedk/TimeoutMap.java

package dk.thoerup.traininfoservice.banedk;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;


public class TimeoutMap<K,V> implements Map<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 TimeoutMap(int timeout) {
                this.timeout = timeout; 
        }


        @Override
        public void clear() {
                cache.clear();
                
        }

        @Override
        public boolean containsKey(Object arg0) {
                CacheItem<V> item = cache.get(arg0);
                
                return (item != null);
        }

        @Override
        public boolean containsValue(Object arg0) {
                return values().contains(arg0);         
        }

        @Override
        public Set<java.util.Map.Entry<K, V>> entrySet() {
                //TODO someday implement this
                throw new UnsupportedOperationException();
        }

        @Override
        public boolean isEmpty() {
                return cache.isEmpty();
        }

        @Override
        public Set<K> keySet() {
                return cache.keySet();
        }

        @Override
        public void putAll(Map<? extends K, ? extends V> arg0) {
                for(K key : arg0.keySet()) {
                        this.put(key, arg0.get(key) );
                }
        }

        @Override
        public V remove(Object arg0) {
                return cache.remove(arg0).value;
        }

        @Override
        public int size() {
                return cache.size();
        }

        @Override
        public Collection<V> values() {
                ArrayList<V> values = new ArrayList<V>();
                for (CacheItem<V> item : cache.values()) {
                        values.add( item.value );
                }
                
                return values;

        }

        @Override
        public V get(Object key) {
                long now = System.currentTimeMillis();
                
                CacheItem<V> item = cache.get(key);
                                
                
                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
                }
        }

        @Override
        public V put(K key, V value) {          
                CacheItem<V> item= new CacheItem<V>(value);
                
                item = cache.put(key, item);
                
                if (item != null)
                        return item.value;
                else
                        return null; 
        }
        
}
1	torben	387	package dk.thoerup.traininfoservice.banedk;
2
3	torben	430	import java.util.ArrayList;
4	torben	428	import java.util.Collection;
5			import java.util.Map;
6			import java.util.Set;
7	torben	430	import java.util.concurrent.ConcurrentHashMap;
8	torben	387
9
10	torben	429
11	torben	428	public class TimeoutMap<K,V> implements Map<K,V>{
12	torben	387
13			class CacheItem<T> {
14
15			public CacheItem(T v) {
16			value = v;
17			lastupdate = System.currentTimeMillis();
18			}
19
20			public long lastupdate;
21			public T value;
22			}
23
24			private ConcurrentHashMap<K,CacheItem<V>> cache = new ConcurrentHashMap<K,CacheItem<V>>();
25			private long timeout;
26
27	torben	428	public TimeoutMap(int timeout) {
28	torben	387	this.timeout = timeout;
29			}
30	torben	428
31
32			@Override
33			public void clear() {
34			cache.clear();
35
36	torben	387	}
37	torben	428
38			@Override
39			public boolean containsKey(Object arg0) {
40			CacheItem<V> item = cache.get(arg0);
41
42			return (item != null);
43			}
44
45			@Override
46			public boolean containsValue(Object arg0) {
47	torben	430	return values().contains(arg0);
48	torben	428	}
49
50			@Override
51			public Set<java.util.Map.Entry<K, V>> entrySet() {
52			//TODO someday implement this
53			throw new UnsupportedOperationException();
54			}
55
56			@Override
57			public boolean isEmpty() {
58			return cache.isEmpty();
59			}
60
61			@Override
62			public Set<K> keySet() {
63			return cache.keySet();
64			}
65
66			@Override
67			public void putAll(Map<? extends K, ? extends V> arg0) {
68	torben	430	for(K key : arg0.keySet()) {
69			this.put(key, arg0.get(key) );
70			}
71	torben	428	}
72
73			@Override
74			public V remove(Object arg0) {
75			return cache.remove(arg0).value;
76			}
77
78			@Override
79			public int size() {
80			return cache.size();
81			}
82
83			@Override
84			public Collection<V> values() {
85	torben	430	ArrayList<V> values = new ArrayList<V>();
86			for (CacheItem<V> item : cache.values()) {
87			values.add( item.value );
88			}
89
90			return values;
91
92	torben	428	}
93
94			@Override
95			public V get(Object key) {
96	torben	387	long now = System.currentTimeMillis();
97
98	torben	428	CacheItem<V> item = cache.get(key);
99	torben	387
100
101			if (item != null) {
102			if ( (item.lastupdate+timeout) < now) { //item too old
103			return null;
104			} else {
105			return item.value; //item still good
106			}
107			} else {
108			return null; // no item found
109			}
110	torben	428	}
111
112			@Override
113			public V put(K key, V value) {
114			CacheItem<V> item= new CacheItem<V>(value);
115	torben	387
116	torben	432	item = cache.put(key, item);
117
118			if (item != null)
119			return item.value;
120			else
121			return null;
122	torben	387	}
123
124			}