Class MapFactory

  extended by org.apache.velocity.util.MapFactory

public class MapFactory
extends Object

Factory class for creating Maps. The main purpose of this class is to take advantage of Java 5 Concurrent classes if they are available. We use reflection to instantiate java.util.concurrent classes to avoid compile time dependency on Java 5. See Issue 607 for more info on this class.

Jarkko Viinamaki

Constructor Summary
Method Summary
static Map create(int size, float loadFactor, int concurrencyLevel, boolean allowNullKeys)
          Creates a new instance of a class that implements Map interface.
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail


public MapFactory()
Method Detail


public static Map create(int size,
                         float loadFactor,
                         int concurrencyLevel,
                         boolean allowNullKeys)
Creates a new instance of a class that implements Map interface. Note that there is a small performance penalty because concurrent maps are created using reflection.

size - initial size of the map
loadFactor - smaller value = better performance, larger value = better memory utilization
concurrencyLevel - estimated number of writer Threads. If this is smaller than 1, HashMap is always returned which is not threadsafe.
allowNullKeys - if true, the returned Map instance supports null keys
one of ConcurrentHashMap, HashMap, Hashtable

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