Package org.apache.commons.collections4.map

Class PredicatedMap<K,​V>

  • Type Parameters:
    K - the type of the keys in this map
    V - the type of the values in this map
    All Implemented Interfaces:
    java.io.Serializable, java.util.Map<K,​V>, Get<K,​V>, IterableGet<K,​V>, IterableMap<K,​V>, Put<K,​V>
    Direct Known Subclasses:
    PredicatedSortedMap
    public class PredicatedMap<K,​V>
extends AbstractMapDecorator<K,​V>
implements java.io.Serializable
    Decorates another Map to validate that additions match a specified predicate.

    This map exists to provide validation for the decorated map. It is normally created to decorate an empty map. If an object cannot be added to the map, an IllegalArgumentException is thrown.

    One usage would be to ensure that no null keys are added to the map. 

    Map map = PredicatedSet.decorate(new HashMap(), NotNullPredicate.INSTANCE, null);

    Note that PredicatedMap 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

    • Nested Class Summary

      • Nested classes/interfaces inherited from interface java.util.Map

        java.util.Map.Entry<K extends java.lang.Object,​V extends java.lang.Object>

    • Method Detail

      • predicatedMap

        public static <K,​V> PredicatedMap<K,​V> predicatedMap​(java.util.Map<K,​V> map,
                                                                 Predicate<? super K> keyPredicate,
                                                                 Predicate<? super V> valuePredicate)
        Factory method to create a predicated (validating) map.

        If there are any elements already in the list being decorated, they are validated.

        Type Parameters:
        K - the key type
        V - the value type
        Parameters:
        map - the map to decorate, must not be null
        keyPredicate - the predicate to validate the keys, null means no check
        valuePredicate - the predicate to validate to values, null means no check
        Returns:
        a new predicated map
        Throws:
        java.lang.NullPointerException - if the map is null
        Since:
        4.0

      • put

        public V put​(K key,
             V value)
        Description copied from interface: Put
        Note that the return type is Object, rather than V as in the Map interface. See the class Javadoc for further info.
        Specified by:
        put in interface java.util.Map<K,​V>
        Specified by:
        put in interface Put<K,​V>
        Overrides:
        put in class AbstractMapDecorator<K,​V>
        Parameters:
        key - key with which the specified value is to be associated
        value - value to be associated with the specified key
        Returns:
        the previous value associated with key, or null if there was no mapping for key. (A null return can also indicate that the map previously associated null with key, if the implementation supports null values.)
        See Also:
        Map.put(Object, Object)

      • putAll

        public void putAll​(java.util.Map<? extends K,​? extends V> mapToCopy)
        Specified by:
        putAll in interface java.util.Map<K,​V>
        Specified by:
        putAll in interface Put<K,​V>
        Overrides:
        putAll in class AbstractMapDecorator<K,​V>
        Parameters:
        mapToCopy - mappings to be stored in this map
        See Also:
        Map.putAll(Map)

      • entrySet

        public java.util.Set<java.util.Map.Entry<K,​V>> entrySet()
        Specified by:
        entrySet in interface Get<K,​V>
        Specified by:
        entrySet in interface java.util.Map<K,​V>
        Overrides:
        entrySet in class AbstractMapDecorator<K,​V>
        Returns:
        a set view of the mappings contained in this map
        See Also:
        Map.entrySet()