UniquePredicate (Commons Collections 3.2.2 API)

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

All Implemented Interfaces:

Serializable, Predicate
```
public final class UniquePredicate
extends Object
implements Predicate, Serializable
```
Predicate implementation that returns true the first time an object is passed into the predicate.

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

Constructor Summary

Constructors
Constructor Description

UniquePredicate()
Constructor that performs no validation.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`evaluate(Object object)`	Evaluates the predicate returning true if the input object hasn't been received yet.
`static Predicate`	`getInstance()`	Factory to create the predicate.

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

- Constructor Detail
  - UniquePredicate
```
public UniquePredicate()
```
    Constructor that performs no validation. Use getInstance if you want that.
- Method Detail
  - getInstance
```
public static Predicate getInstance()
```
    Factory to create the predicate.
    
    Returns:
    
    the predicate
    
    Throws:
    
    IllegalArgumentException - if the predicate is null
  - evaluate
```
public boolean evaluate(Object object)
```
    Evaluates the predicate returning true if the input object hasn't been received yet.
    
    Specified by:
    
    evaluate in interface Predicate
    
    Parameters:
    
    object - the input object
    
    Returns:
    
    true if this is the first time the object is seen