Package org.apache.commons.collections4.map

Class PredicatedMap<K,V>

java.lang.Object
org.apache.commons.collections4.map.AbstractIterableMap<K,V>
org.apache.commons.collections4.map.AbstractMapDecorator<K,V>
org.apache.commons.collections4.map.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:
Serializable, 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 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:

  • Field Details

  • Constructor Details

    • PredicatedMap

      protected PredicatedMap(Map<K,V> map, Predicate<? super K> keyPredicate, Predicate<? super V> valuePredicate)
      Constructor that wraps (not copies).
      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
      Throws:
      NullPointerException - if the map is null

  • Method Details

    • predicatedMap

      public static <K, V> PredicatedMap<K,V> predicatedMap(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:
      NullPointerException - if the map is null
      Since:
      4.0

    • checkSetValue

      protected V checkSetValue(V value)
      Override to validate an object set into the map via setValue.
      Parameters:
      value - the value to validate
      Returns:
      the value itself
      Throws:
      IllegalArgumentException - if invalid
      Since:
      3.1

    • isSetValueChecking

      protected boolean isSetValueChecking()
      Override to only return true when there is a value transformer.
      Returns:
      true if a value predicate is in use
      Since:
      3.1

    • 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 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:

    • putAll

      public void putAll(Map<? extends K,? extends V> mapToCopy)
      Specified by:
      putAll in interface 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:

    • validate

      protected void validate(K key, V value)
      Validates a key value pair.
      Parameters:
      key - the key to validate
      value - the value to validate
      Throws:
      IllegalArgumentException - if invalid

    • entrySet

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