Class PredicatedMap<K,V>
- java.lang.Object
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- org.apache.commons.collections4.map.AbstractIterableMap<K,V>
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- org.apache.commons.collections4.map.AbstractMapDecorator<K,V>
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- org.apache.commons.collections4.map.AbstractInputCheckedMapDecorator<K,V>
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- org.apache.commons.collections4.map.PredicatedMap<K,V>
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- Type Parameters:
K
- the type of the keys in this mapV
- 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 AbstractInputCheckedMapDecorator<K,V> implements java.io.Serializable
Decorates anotherMap
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
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Field Summary
Fields Modifier and Type Field Description protected Predicate<? super K>
keyPredicate
The key predicate to useprivate static long
serialVersionUID
Serialization versionprotected Predicate<? super V>
valuePredicate
The value predicate to use-
Fields inherited from class org.apache.commons.collections4.map.AbstractMapDecorator
map
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description protected V
checkSetValue(V value)
Override to validate an object set into the map viasetValue
.protected boolean
isSetValueChecking()
Override to only return true when there is a value transformer.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.V
put(K key, V value)
Note that the return type is Object, rather than V as in the Map interface.void
putAll(java.util.Map<? extends K,? extends V> mapToCopy)
private void
readObject(java.io.ObjectInputStream in)
Read the map in using a custom routine.protected void
validate(K key, V value)
Validates a key value pair.private void
writeObject(java.io.ObjectOutputStream out)
Write the map out using a custom routine.-
Methods inherited from class org.apache.commons.collections4.map.AbstractInputCheckedMapDecorator
entrySet
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Methods inherited from class org.apache.commons.collections4.map.AbstractMapDecorator
clear, containsKey, containsValue, decorated, equals, get, hashCode, isEmpty, keySet, remove, size, toString, values
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Methods inherited from class org.apache.commons.collections4.map.AbstractIterableMap
mapIterator
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Field Detail
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serialVersionUID
private static final long serialVersionUID
Serialization version- See Also:
- Constant Field Values
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Constructor Detail
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PredicatedMap
protected PredicatedMap(java.util.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 nullkeyPredicate
- the predicate to validate the keys, null means no checkvaluePredicate
- the predicate to validate to values, null means no check- Throws:
java.lang.NullPointerException
- if the map is null
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Method Detail
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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 typeV
- the value type- Parameters:
map
- the map to decorate, must not be nullkeyPredicate
- the predicate to validate the keys, null means no checkvaluePredicate
- 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
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writeObject
private void writeObject(java.io.ObjectOutputStream out) throws java.io.IOException
Write the map out using a custom routine.- Parameters:
out
- the output stream- Throws:
java.io.IOException
- if an error occurs while writing to the stream- Since:
- 3.1
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readObject
private void readObject(java.io.ObjectInputStream in) throws java.io.IOException, java.lang.ClassNotFoundException
Read the map in using a custom routine.- Parameters:
in
- the input stream- Throws:
java.io.IOException
- if an error occurs while reading from the streamjava.lang.ClassNotFoundException
- if an object read from the stream can not be loaded- Since:
- 3.1
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validate
protected void validate(K key, V value)
Validates a key value pair.- Parameters:
key
- the key to validatevalue
- the value to validate- Throws:
java.lang.IllegalArgumentException
- if invalid
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checkSetValue
protected V checkSetValue(V value)
Override to validate an object set into the map viasetValue
.- Specified by:
checkSetValue
in classAbstractInputCheckedMapDecorator<K,V>
- Parameters:
value
- the value to validate- Returns:
- the value itself
- Throws:
java.lang.IllegalArgumentException
- if invalid- Since:
- 3.1
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isSetValueChecking
protected boolean isSetValueChecking()
Override to only return true when there is a value transformer.- Overrides:
isSetValueChecking
in classAbstractInputCheckedMapDecorator<K,V>
- Returns:
- true if a value predicate is in use
- Since:
- 3.1
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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 interfacejava.util.Map<K,V>
- Specified by:
put
in interfacePut<K,V>
- Overrides:
put
in classAbstractMapDecorator<K,V>
- Parameters:
key
- key with which the specified value is to be associatedvalue
- value to be associated with the specified key- Returns:
- the previous value associated with
key
, ornull
if there was no mapping forkey
. (Anull
return can also indicate that the map previously associatednull
withkey
, if the implementation supportsnull
values.) - See Also:
Map.put(Object, Object)
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