Class MapCache

cache/src/main/java/org/apache/shiro/cache/MapCache.java:34–100

A MapCache is a Cache Cache implementation that uses a backing Map instance to store and retrieve cached data. @param K @param V @since 1.0

 * @since 1.0
 */
public class MapCache<K, V> implements Cache<K, V> {

    /**
     * Backing instance.
     */
    private final Map<K, V> map;

    /**
     * The name of this cache.
     */
    private final String name;

    public MapCache(String name, Map<K, V> backingMap) {
        if (name == null) {
            throw new IllegalArgumentException("Cache name cannot be null.");
        }
        if (backingMap == null) {
            throw new IllegalArgumentException("Backing map cannot be null.");
        }
        this.name = name;
        this.map = backingMap;
    }

    public V get(K key) throws CacheException {
        return map.get(key);
    }

    public V put(K key, V value) throws CacheException {
        return map.put(key, value);
    }

    public V remove(K key) throws CacheException {
        return map.remove(key);
    }

    public void clear() throws CacheException {
        map.clear();
    }

    public int size() {
        return map.size();
    }

    public Set<K> keys() {
        Set<K> keys = map.keySet();
        if (!keys.isEmpty()) {
            return Collections.unmodifiableSet(keys);
        }
        return Collections.emptySet();
    }

    public Collection<V> values() {
        Collection<V> values = map.values();
        if (!values.isEmpty()) {
            return Collections.unmodifiableCollection(values);
        }
        return Collections.emptyList();
    }