Package org.apache.commons.collections.map

Class PredicatedMap

java.lang.Object
org.apache.commons.collections.map.AbstractMapDecorator
org.apache.commons.collections.map.PredicatedMap
All Implemented Interfaces:
Serializable, Map
Direct Known Subclasses:
PredicatedSortedMap
public class PredicatedMap extends AbstractMapDecorator 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:
Commons Collections 3.0
Version:
$Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
Author:
Stephen Colebourne, Paul Jack
See Also:

  • Field Details

    • keyPredicate

      protected final Predicate keyPredicate
      The key predicate to use

    • valuePredicate

      protected final Predicate valuePredicate
      The value predicate to use

  • Constructor Details

    • PredicatedMap

      protected PredicatedMap(Map map, Predicate keyPredicate, Predicate 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:
      IllegalArgumentException - if the map is null

  • Method Details

    • decorate

      public static Map decorate(Map map, Predicate keyPredicate, Predicate valuePredicate)
      Factory method to create a predicated (validating) map.

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

      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:
      IllegalArgumentException - if the map is null

    • validate

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

    • checkSetValue

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

    • put

      public Object put(Object key, Object value)
      Specified by:
      put in interface Map
      Overrides:
      put in class AbstractMapDecorator

    • putAll

      public void putAll(Map mapToCopy)
      Specified by:
      putAll in interface Map
      Overrides:
      putAll in class AbstractMapDecorator

    • entrySet

      public Set entrySet()
      Specified by:
      entrySet in interface Map
      Overrides:
      entrySet in class AbstractMapDecorator