org.cripac.isee.util

Class Singleton<T>

java.lang.Object

org.cripac.isee.util.Singleton<T>

Type Parameters:

T - The type of the object.

All Implemented Interfaces:

Serializable

public class Singleton<T>
extends Object
implements Serializable

The class Singleton manages singletons of any types.

Author:

Ken Yu, CRIPAC, 2016

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private static Map<Class<?>,Object>	instancePool Lazy-evaluated instance pool of all the classes.
private Factory<? extends T>	objFactory Factory for creating a new instance if there is not instance in the pool of class T.
private static long	serialVersionUID
private Class<? extends T>	type Class T.

Constructor Summary

Constructors

Constructor and Description
Singleton(Factory<U> objFactory, Class<U> type) Create a singleton manager of specified class T.

Method Summary

Modifier and Type	Method and Description
private void	checkPool() Check existence of the instance pool.
T	getInst() Get an instance of class T.

Methods inherited from class java.lang.Object

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

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

instancePool

private static volatile Map<Class<?>,Object> instancePool

Lazy-evaluated instance pool of all the classes.

objFactory

private final Factory<? extends T> objFactory

Factory for creating a new instance if there is not instance in the pool of class T.

type

private final Class<? extends T> type

Class T.

Constructor Detail

Singleton

public Singleton(Factory<U> objFactory,
                 Class<U> type)
          throws Exception

Create a singleton manager of specified class T.

Parameters:

objFactory - Factory to create new instance of class T when instance of it does not exist.

Throws:

Exception - On failure creating a new instance.

Method Detail

checkPool

private void checkPool()

Check existence of the instance pool.

getInst

public T getInst()
          throws Exception

Get an instance of class T.

Returns:

A singleton instance.

Throws:

Exception - On failure creating a new instance.