org.apache.river.lookup.util

Class ConsistentMap<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

org.apache.river.lookup.util.ConsistentMap<K,V>

All Implemented Interfaces:

Serializable, Map<K,V>

public class ConsistentMap<K,V>
extends AbstractMap<K,V>
implements Serializable

An implementation of the java.util.Map interface that has a serialized form consistent in all virtual machines. ConsistentMap instances are unmodifiable. All mutator methods, such as add and remove, throw UnsupportedOperationException. This class permits null values and the null key.

Although instances of this class are unmodifiable, they are not necessarily immutable. If a client retrieves a mutable object (either a key or value) contained in a ConsistentMap and mutates that object, the client in effect mutates the state of the ConsistentMap. In this case, the serialized form of the ConsistentMap will most likely also have been mutated. A ConsistentMap that contains only immutable objects will maintain a consistent serialized form indefinitely. But a ConsistentMap that contains mutable objects will maintain a consistent serialized form only so long as the mutable objects are not mutated.

Author:

Bill Venners

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

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

Map.Entry<K,V>

Constructor Summary

Constructors

Constructor and Description
ConsistentMap() Constructs a new, empty ConsistentMap.
ConsistentMap(AtomicSerial.GetArg arg)
ConsistentMap(Map<K,V> init) Constructs a new ConsistentMap containing the elements in the passed collection.

Method Summary

Modifier and Type	Method and Description
Set<Map.Entry<K,V>>	entrySet() Returns a set view of the mappings contained in this ConsistentMap.

Methods inherited from class java.util.AbstractMap

clear, clone, containsKey, containsValue, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, toString, values

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

Constructor Detail

ConsistentMap

public ConsistentMap()

Constructs a new, empty ConsistentMap. All instances of ConsistentMap are unmodifiable.

ConsistentMap

public ConsistentMap(Map<K,V> init)

Constructs a new ConsistentMap containing the elements in the passed collection. All instances of ConsistentMap are unmodifiable.

Parameters:

init - the map whose elements are to be placed into this map.

Throws:

NullPointerException - if the passed init reference is null

ConsistentMap

public ConsistentMap(AtomicSerial.GetArg arg)
              throws IOException

Throws:

IOException

Method Detail

entrySet

public Set<Map.Entry<K,V>> entrySet()

Returns a set view of the mappings contained in this ConsistentMap. Each element in the returned set is a Map.Entry

Specified by:

entrySet in interface Map<K,V>

Specified by:

entrySet in class AbstractMap<K,V>

Returns:

a set view of the mappings contained in this ConsistentMap.