com.phloc.commons.collections

Class SingleElementMap<KEYTYPE,VALUETYPE>

java.lang.Object

com.phloc.commons.collections.SingleElementMap<KEYTYPE,VALUETYPE>

Type Parameters:

KEYTYPE - The key type.

VALUETYPE - The value type.

All Implemented Interfaces:

IHasSize, Map<KEYTYPE,VALUETYPE>

@NotThreadSafe
public final class SingleElementMap<KEYTYPE,VALUETYPE>
extends Object
implements Map<KEYTYPE,VALUETYPE>, IHasSize

Map implementation that can only keep 0 or 1 element.

Author:

Philip Helger

Nested Class Summary

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

Map.Entry<K,V>

Constructor Summary

Constructors

Constructor and Description
SingleElementMap()
SingleElementMap(KEYTYPE aKey, VALUETYPE aValue)

Method Summary

Methods

Modifier and Type	Method and Description
void	clear()
boolean	containsKey(Object aKey)
boolean	containsValue(Object aValue)
Set<Map.Entry<KEYTYPE,VALUETYPE>>	entrySet()
boolean	equals(Object o)
VALUETYPE	get(Object aKey)
int	hashCode()
boolean	isEmpty()
Set<KEYTYPE>	keySet()
VALUETYPE	put(KEYTYPE aKey, VALUETYPE aElement)
void	putAll(Map<? extends KEYTYPE,? extends VALUETYPE> aMap)
VALUETYPE	remove(Object aKey)
int	size()
String	toString()
Collection<VALUETYPE>	values()

Methods inherited from class java.lang.Object

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

Constructor Detail

SingleElementMap

public SingleElementMap()

SingleElementMap

public SingleElementMap(@Nullable
                KEYTYPE aKey,
                @Nullable
                VALUETYPE aValue)

Method Detail

clear

public void clear()

Specified by:

clear in interface Map<KEYTYPE,VALUETYPE>

containsKey

public boolean containsKey(@Nullable
                  Object aKey)

Specified by:

containsKey in interface Map<KEYTYPE,VALUETYPE>

containsValue

public boolean containsValue(@Nullable
                    Object aValue)

Specified by:

containsValue in interface Map<KEYTYPE,VALUETYPE>

get

@Nullable
public VALUETYPE get(@Nullable
                     Object aKey)

Specified by:

get in interface Map<KEYTYPE,VALUETYPE>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface IHasSize

Specified by:

isEmpty in interface Map<KEYTYPE,VALUETYPE>

Returns:

true if no items are present, false if at least a single item is present.

See Also:

IHasSize.size()

put

@Nullable
public VALUETYPE put(@Nullable
                     KEYTYPE aKey,
                     @Nullable
                     VALUETYPE aElement)

Specified by:

put in interface Map<KEYTYPE,VALUETYPE>

putAll

public void putAll(@Nullable
          Map<? extends KEYTYPE,? extends VALUETYPE> aMap)

Specified by:

putAll in interface Map<KEYTYPE,VALUETYPE>

remove

@Nullable
public VALUETYPE remove(@Nullable
                        Object aKey)

Specified by:

remove in interface Map<KEYTYPE,VALUETYPE>

size

@Nonnegative
public int size()

Specified by:

size in interface IHasSize

Specified by:

size in interface Map<KEYTYPE,VALUETYPE>

Returns:

The number of contained elements. Always ≥ 0.

keySet

@ReturnsImmutableObject
@Nonnull
public Set<KEYTYPE> keySet()

Specified by:

keySet in interface Map<KEYTYPE,VALUETYPE>

values

@ReturnsImmutableObject
@Nonnull
public Collection<VALUETYPE> values()

Specified by:

values in interface Map<KEYTYPE,VALUETYPE>

entrySet

@Nonnull
public Set<Map.Entry<KEYTYPE,VALUETYPE>> entrySet()

Specified by:

entrySet in interface Map<KEYTYPE,VALUETYPE>

equals

public boolean equals(Object o)

Specified by:

equals in interface Map<KEYTYPE,VALUETYPE>

Overrides:

equals in class Object

hashCode

public int hashCode()

Specified by:

hashCode in interface Map<KEYTYPE,VALUETYPE>

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object