Package org.jibx.util

Class ChainedMap

java.lang.Object

org.jibx.util.ChainedMap

All Implemented Interfaces:

Map

public class ChainedMap
extends Object
implements Map

Partial implementation of Map which provides a merged view of a defaults map with an overrides map. Although this can be used as a map for most purposes, methods which return live views of the keys or values in the map only take into account the overrides, not the defaults.

Nested Class Summary

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

Map.Entry<K extends Object,V extends Object>

Constructor Summary

Constructors

Constructor	Description
ChainedMap(Map defaults)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	clear()	Clear all override key-value pairs.
boolean	containsKey(Object key)	Check if a key has a defined value.
boolean	containsValue(Object value)	Check if a value is present.
Set	entrySet()	Get the set of entries.
Object	get(Object key)	Get value for key.
boolean	isEmpty()	Check if no overrides are defined.
Set	keySet()	Get the set of keys.
Object	put(Object key, Object value)	Set an override value.
void	putAll(Map map)	Add all key-value pairs from another map into the overrides map.
Object	remove(Object key)	Remove a key-value pair.
int	size()	Get the number of entries in the map.
Collection	values()	Get the values.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Map

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

Constructor Detail

ChainedMap

public ChainedMap(Map defaults)

Constructor.

Parameters:

defaults - map providing defaults for keys not set directly

Method Detail

clear

public void clear()

Clear all override key-value pairs. This only effects the overrides, not the defaults.

Specified by:

clear in interface Map

containsKey

public boolean containsKey(Object key)

Check if a key has a defined value. This will return true if the key is present in the overrides map with a non-null value, or if the key is not present in the overrides map but is present in the defaults map.

Specified by:

containsKey in interface Map

Parameters:

key - Key

Returns:

true if key defined, false if not

containsValue

public boolean containsValue(Object value)

Check if a value is present. This only checks for the value in the overrides map.

Specified by:

containsValue in interface Map

Parameters:

value - to check

Returns:

true if value present as an override, false if not

entrySet

public Set entrySet()

Get the set of entries. This only returns the entries in the overrides map.

Specified by:

entrySet in interface Map

Returns:

override entries

get

public Object get(Object key)

Get value for key. If the key is present in the overrides map, the value from that map is returned; otherwise, the value for the key in the defaults map is returned.

Specified by:

get in interface Map

Parameters:

key - Key

Returns:

value (null if key not present)

isEmpty

public boolean isEmpty()

Check if no overrides are defined.

Specified by:

isEmpty in interface Map

Returns:

true if no overrides, false if any present

keySet

public Set keySet()

Get the set of keys. This only returns the keys in the overrides map.

Specified by:

keySet in interface Map

Returns:

keys

put

public Object put(Object key,
                  Object value)

Set an override value. This just adds the key-value pair to the override map.

Specified by:

put in interface Map

Parameters:

key - Key

value - to set

Returns:

previous value for key (from default map, if not present in overrides)

putAll

public void putAll(Map map)

Add all key-value pairs from another map into the overrides map.

Specified by:

putAll in interface Map

Parameters:

map - to add

remove

public Object remove(Object key)

Remove a key-value pair. If the key was previously present in the overrides map it is simply removed from that map. If it was not present in the overrides map but is present in the defaults map, a null entry is added to the overrides map for that key.

Specified by:

remove in interface Map

Parameters:

key - Key

Returns:

previous value for key

size

public int size()

Get the number of entries in the map. This returns the entry count for the overrides map only.

Specified by:

size in interface Map

Returns:

entry count

values

public Collection values()

Get the values. This returns only the values in the overrides map.

Specified by:

values in interface Map

Returns:

values