Package com.google.gwt.storage.client

Class StorageMap

java.lang.Object

java.util.AbstractMap<String,String>

com.google.gwt.storage.client.StorageMap

All Implemented Interfaces:

Map<String,String>

public class StorageMap
extends AbstractMap<String,String>

Exposes the local/session Storage as a standard Map<String, String>.

Experimental API: This API is still under development and is subject to change.

The following characteristics are associated with this Map:

1. Mutable - All 'write' methods (put(String, String), AbstractMap.putAll(Map), remove(Object), clear(), Map.Entry.setValue(Object)) operate as intended;
2. remove() on Iterators - All remove() operations on available Iterators (from AbstractMap.keySet(), entrySet() and AbstractMap.values()) operate as intended;
3. No null values and keys - The Storage doesn't accept keys or values which are null;
4. String values and keys - All keys and values in this Map are String types.

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	Description
StorageMap(Storage storage)	Creates the Map with the specified Storage as data provider.

Method Summary

Modifier and Type	Method	Description
void	clear()	Removes all items from the Storage.
boolean	containsKey(Object key)	Returns true if the Storage contains the specified key, false otherwise.
boolean	containsValue(Object value)	Returns true if the Storage contains the specified value, false otherwise (or if the specified key is null ).
Set<Map.Entry<String,String>>	entrySet()	Returns a Set containing all entries of the Storage.
String	get(Object key)	Returns the value associated with the specified key in the Storage.
String	put(String key, String value)	Adds (or overwrites) a new key/value pair in the Storage.
String	remove(Object key)	Removes the key/value pair from the Storage.
int	size()	Returns the number of items in the Storage.

Methods inherited from class java.util.AbstractMap

clone, equals, hashCode, isEmpty, keySet, putAll, 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 Details

StorageMap

public StorageMap(Storage storage)

Creates the Map with the specified Storage as data provider.

Parameters:

storage - a local/session Storage instance obtained by either Storage.getLocalStorageIfSupported() or Storage.getSessionStorageIfSupported().

Method Details

clear

public void clear()

Removes all items from the Storage.

Specified by:

clear in interface Map<String,String>

Overrides:

clear in class AbstractMap<String,String>

See Also:

• Storage.clear()

containsKey

public boolean containsKey(Object key)

Returns true if the Storage contains the specified key, false otherwise.

Specified by:

containsKey in interface Map<String,String>

Overrides:

containsKey in class AbstractMap<String,String>

containsValue

public boolean containsValue(Object value)

Returns true if the Storage contains the specified value, false otherwise (or if the specified key is null ).

Specified by:

containsValue in interface Map<String,String>

Overrides:

containsValue in class AbstractMap<String,String>

entrySet

public Set<Map.Entry<String,String>> entrySet()

Returns a Set containing all entries of the Storage.

Specified by:

entrySet in interface Map<String,String>

Specified by:

entrySet in class AbstractMap<String,String>

get

public String get(Object key)

Returns the value associated with the specified key in the Storage.

Specified by:

get in interface Map<String,String>

Overrides:

get in class AbstractMap<String,String>

Parameters:

key - the key identifying the value

See Also:

• Storage.getItem(String)

put

public String put(String key,
 String value)

Adds (or overwrites) a new key/value pair in the Storage.

Specified by:

put in interface Map<String,String>

Overrides:

put in class AbstractMap<String,String>

Parameters:

key - the key identifying the value (not null)

value - the value associated with the key (not null)

See Also:

• Storage.setItem(String, String)

remove

public String remove(Object key)

Removes the key/value pair from the Storage.

Specified by:

remove in interface Map<String,String>

Overrides:

remove in class AbstractMap<String,String>

Parameters:

key - the key identifying the item to remove

Returns:

the value associated with the key - null if the key was not present in the Storage

See Also:

• Storage.removeItem(String)

size

public int size()

Returns the number of items in the Storage.

Specified by:

size in interface Map<String,String>

Overrides:

size in class AbstractMap<String,String>

Returns:

the number of items

See Also:

• Storage.getLength()