Package org.apache.commons.collections4
Interface Predicate<T>
- Type Parameters:
T
- the type that the predicate queries
- All Known Subinterfaces:
PredicateDecorator<T>
- All Known Implementing Classes:
AbstractQuantifierPredicate
,AllPredicate
,AndPredicate
,AnyPredicate
,ComparatorPredicate
,EqualPredicate
,ExceptionPredicate
,FalsePredicate
,IdentityPredicate
,InstanceofPredicate
,NonePredicate
,NotNullPredicate
,NotPredicate
,NullIsExceptionPredicate
,NullIsFalsePredicate
,NullIsTruePredicate
,NullPredicate
,OnePredicate
,OrPredicate
,TransformedPredicate
,TransformerPredicate
,TruePredicate
,UniquePredicate
- Functional Interface:
- This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
Defines a functor interface implemented by classes that perform a predicate
test on an object.
A Predicate
is the object equivalent of an if
statement.
It uses the input object to return a true or false value, and is often used in
validation or filtering.
Standard implementations of common predicates are provided by
PredicateUtils
. These include true, false, instanceof, equals, and,
or, not, method invocation and null testing.
- Since:
- 1.0
-
Method Summary
-
Method Details
-
evaluate
Use the specified parameter to perform a test that returns true or false.- Parameters:
object
- the object to evaluate, should not be changed- Returns:
- true or false
- Throws:
ClassCastException
- (runtime) if the input is the wrong classIllegalArgumentException
- (runtime) if the input is invalidFunctorException
- (runtime) if the predicate encounters a problem
-