org.apache.velocity.util

Class MapFactory

java.lang.Object

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.

Since:

1.6

Author:

Jarkko Viinamaki

Constructor Summary

Constructors

Constructor and Description
MapFactory()

Method Summary

Modifier and Type	Method and Description
static Map	create(boolean allowNullKeys) Creates a new instance of a class that implements Map interface using the JDK defaults for initial size, load factor, etc.
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

MapFactory

public MapFactory()

Method Detail

create

public static Map create(boolean allowNullKeys)

Creates a new instance of a class that implements Map interface using the JDK defaults for initial size, load factor, etc. Note that there is a small performance penalty because concurrent maps are created using reflection.

Parameters:

allowNullKeys - if true, the returned Map instance supports null keys

Returns:

one of ConcurrentHashMap, HashMap, Hashtable

create

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.

Parameters:

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

Returns:

one of ConcurrentHashMap, HashMap, Hashtable