org.zkoss.util

Class FilterMap<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

org.zkoss.util.FilterMap<K,V>

All Implemented Interfaces:

java.util.Map<K,V>

public class FilterMap<K,V>
extends java.util.AbstractMap<K,V>

A map that allows the value to be evaluated before returning (so called filtering). For example, if you allow the value to have EL expressions and want to evaluate it before returning, then you could implement FilterMap.Filter to evaluate the value when the value is retrieved. Then, encapsulate the original map with this class. For example,

 return new FilterMap(map,
     new FilterMap.Filter() {
         public Object filter(Object key, Object value) {
             //evaluate the value and return the result
         }
     });

Notice that this map is readonly, and it is thread-safe if the give map and the filter are both thread safe.

Since:

5.0.7

Author:

tomyeh

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	FilterMap.Filter<V> Filters the given value (to evaluate when the value is retrieved).

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

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

Constructor Summary

Constructors

Constructor and Description
FilterMap(java.util.Map<K,V> map, FilterMap.Filter<V> filter)

Method Summary

Modifier and Type	Method and Description
boolean	containsKey(java.lang.Object key)
java.util.Set<java.util.Map.Entry<K,V>>	entrySet()
boolean	equals(java.lang.Object o)
V	get(java.lang.Object key)
java.util.Map<K,V>	getOrigin() Returns the original map being filtered.
int	hashCode()
java.lang.String	toString()

Methods inherited from class java.util.AbstractMap

clear, clone, containsValue, isEmpty, keySet, put, putAll, remove, size, 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

FilterMap

public FilterMap(java.util.Map<K,V> map,
                 FilterMap.Filter<V> filter)

Method Detail

getOrigin

public java.util.Map<K,V> getOrigin()

Returns the original map being filtered. That is, the map passed to the constructor.

get

public V get(java.lang.Object key)

Specified by:

get in interface java.util.Map<K,V>

Overrides:

get in class java.util.AbstractMap<K,V>

containsKey

public boolean containsKey(java.lang.Object key)

Specified by:

containsKey in interface java.util.Map<K,V>

Overrides:

containsKey in class java.util.AbstractMap<K,V>

entrySet

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

Specified by:

entrySet in interface java.util.Map<K,V>

Specified by:

entrySet in class java.util.AbstractMap<K,V>

toString

public java.lang.String toString()

Overrides:

toString in class java.util.AbstractMap<K,V>

hashCode

public int hashCode()

Specified by:

hashCode in interface java.util.Map<K,V>

Overrides:

hashCode in class java.util.AbstractMap<K,V>

equals

public boolean equals(java.lang.Object o)

Specified by:

equals in interface java.util.Map<K,V>

Overrides:

equals in class java.util.AbstractMap<K,V>