ConstantFactory (Commons Collections 3.2.2 API)

java.lang.Object
- org.apache.commons.collections.functors.ConstantFactory

All Implemented Interfaces:

Serializable, Factory
```
public class ConstantFactory
extends Object
implements Factory, Serializable
```
Factory implementation that returns the same constant each time.
No check is made that the object is immutable. In general, only immutable objects should use the constant factory. Mutable objects should use the prototype factory.

Since:

Commons Collections 3.0

Version:

$Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $

Author:

Stephen Colebourne

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type Field Description

static Factory NULL_INSTANCE
Returns null each time

Constructor Summary

Constructors
Constructor Description

ConstantFactory(Object constantToReturn)
Constructor that performs no validation.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Object`	`create()`	Always return constant.
`Object`	`getConstant()`	Gets the constant.
`static Factory`	`getInstance(Object constantToReturn)`	Factory method that performs validation.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - NULL_INSTANCE
```
public static final Factory NULL_INSTANCE
```
    Returns null each time
- Constructor Detail
  - ConstantFactory
```
public ConstantFactory(Object constantToReturn)
```
    Constructor that performs no validation. Use getInstance if you want that.
    
    Parameters:
    
    constantToReturn - the constant to return each time
- Method Detail
  - getInstance
```
public static Factory getInstance(Object constantToReturn)
```
    Factory method that performs validation.
    
    Parameters:
    
    constantToReturn - the constant object to return each time in the factory
    
    Returns:
    
    the constant factory.
  - create
```
public Object create()
```
    Always return constant.
    
    Specified by:
    
    create in interface Factory
    
    Returns:
    
    the stored constant value
  - getConstant
```
public Object getConstant()
```
    Gets the constant.
    
    Returns:
    
    the constant
    
    Since:
    
    Commons Collections 3.1