UniquePredicate (Apache Commons Collections 4.2 API)

java.lang.Object
- org.apache.commons.collections4.functors.UniquePredicate<T>

All Implemented Interfaces:

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

Since:

3.0

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(T object)`	Evaluates the predicate returning true if the input object hasn't been received yet.
`static <T> Predicate<T>`	`uniquePredicate()`	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 uniquePredicate if you want that.
- Method Detail
  - uniquePredicate
```
public static <T> Predicate<T> uniquePredicate()
```
    Factory to create the predicate.
    
    Type Parameters:
    
    T - the type that the predicate queries
    
    Returns:
    
    the predicate
    
    Throws:
    
    IllegalArgumentException - if the predicate is null
  - evaluate
```
public boolean evaluate(T object)
```
    Evaluates the predicate returning true if the input object hasn't been received yet.
    
    Specified by:
    
    evaluate in interface Predicate<T>
    
    Parameters:
    
    object - the input object
    
    Returns:
    
    true if this is the first time the object is seen