org.apache.commons.collections4.map

Class FixedSizeMap<K,V>

  • All Implemented Interfaces:
    Serializable, Map<K,V>, BoundedMap<K,V>, Get<K,V>, IterableGet<K,V>, IterableMap<K,V>, Put<K,V> 

    public class FixedSizeMap<K,V>
extends AbstractMapDecorator<K,V>
implements BoundedMap<K,V>, Serializable
    Decorates another Map to fix the size, preventing add/remove.

    Any action that would change the size of the map is disallowed. The put method is allowed to change the value associated with an existing key however.

    If trying to remove or clear the map, an UnsupportedOperationException is thrown. If trying to put a new mapping into the map, an IllegalArgumentException is thrown. This is because the put method can succeed if the mapping's key already exists in the map, so the put method is not always unsupported.

    Note that FixedSizeMap is not synchronized and is not thread-safe. If you wish to use this map from multiple threads concurrently, you must use appropriate synchronization. The simplest approach is to wrap this map using Collections.synchronizedMap(Map). This class may throw exceptions when accessed by concurrent threads without synchronization.

    This class is Serializable from Commons Collections 3.1.

    Since:
    3.0
    See Also:
    Serialized Form