Package org.apache.commons.collections.functors

This package contains implementations of the Closure, Predicate, Transformer and Factory interfaces.

See: Description

Interface Summary

Interface	Description
PredicateDecorator	Defines a predicate that decorates one or more other predicates.

Class Summary

Class	Description
AllPredicate	Predicate implementation that returns true if all the predicates return true.
AndPredicate	Predicate implementation that returns true if both the predicates return true.
AnyPredicate	Predicate implementation that returns true if any of the predicates return true.
ChainedClosure	Closure implementation that chains the specified closures together.
ChainedTransformer	Transformer implementation that chains the specified transformers together.
CloneTransformer	Transformer implementation that returns a clone of the input object.
ClosureTransformer	Transformer implementation that calls a Closure using the input object and then returns the input.
ConstantFactory	Factory implementation that returns the same constant each time.
ConstantTransformer	Transformer implementation that returns the same constant each time.
EqualPredicate	Predicate implementation that returns true if the input is the same object as the one stored in this predicate by equals.
ExceptionClosure	Closure implementation that always throws an exception.
ExceptionFactory	Factory implementation that always throws an exception.
ExceptionPredicate	Predicate implementation that always throws an exception.
ExceptionTransformer	Transformer implementation that always throws an exception.
FactoryTransformer	Transformer implementation that calls a Factory and returns the result.
FalsePredicate	Predicate implementation that always returns false.
ForClosure	Closure implementation that calls another closure n times, like a for loop.
IdentityPredicate	Predicate implementation that returns true if the input is the same object as the one stored in this predicate.
IfClosure	Closure implementation acts as an if statement calling one or other closure based on a predicate.
InstanceofPredicate	Predicate implementation that returns true if the input is an instanceof the type stored in this predicate.
InstantiateFactory	Factory implementation that creates a new object instance by reflection.
InstantiateTransformer	Transformer implementation that creates a new object instance by reflection.
InvokerTransformer	Transformer implementation that creates a new object instance by reflection.
MapTransformer	Transformer implementation that returns the value held in a specified map using the input parameter as a key.
NonePredicate	Predicate implementation that returns true if none of the predicates return true.
NOPClosure	Closure implementation that does nothing.
NOPTransformer	Transformer implementation that does nothing.
NotNullPredicate	Predicate implementation that returns true if the input is not null.
NotPredicate	Predicate implementation that returns the opposite of the decorated predicate.
NullIsExceptionPredicate	Predicate implementation that throws an exception if the input is null.
NullIsFalsePredicate	Predicate implementation that returns false if the input is null.
NullIsTruePredicate	Predicate implementation that returns true if the input is null.
NullPredicate	Predicate implementation that returns true if the input is null.
OnePredicate	Predicate implementation that returns true if only one of the predicates return true.
OrPredicate	Predicate implementation that returns true if either of the predicates return true.
PredicateTransformer	Transformer implementation that calls a Predicate using the input object and then returns the input.
PrototypeFactory	Factory implementation that creates a new instance each time based on a prototype.
StringValueTransformer	Transformer implementation that returns the result of calling String.valueOf on the input object.
SwitchClosure	Closure implementation calls the closure whose predicate returns true, like a switch statement.
SwitchTransformer	Transformer implementation calls the transformer whose predicate returns true, like a switch statement.
TransformedPredicate	Predicate implementation that transforms the given object before invoking another Predicate.
TransformerClosure	Closure implementation that calls a Transformer using the input object and ignore the result.
TransformerPredicate	Predicate implementation that returns the result of a transformer.
TruePredicate	Predicate implementation that always returns true.
UniquePredicate	Predicate implementation that returns true the first time an object is passed into the predicate.
WhileClosure	Closure implementation that executes a closure repeatedly until a condition is met, like a do-while or while loop.

Package org.apache.commons.collections.functors Description

This package contains implementations of the Closure, Predicate, Transformer and Factory interfaces. These provide simple callbacks for processing with collections.

WARNING: from v3.2.2 onwards this several classes in this package will throw an UnsupportedOperationException when trying to serialize or de-serialize an instance to prevent potential remote code execution exploits.

Classes considered to be unsafe are:

• CloneTransformer
• ForClosure
• InstantiateFactory
• InstantiateTransformer
• InvokerTransformer
• PrototypeFactory$PrototypeCloneFactory
• PrototypeFactory$PrototypeSerializationFactory
• WhileClosure

In order to re-enable serialization support for these unsafe classes, the following system property can be used (via -Dproperty=true):

org.apache.commons.collections.enableUnsafeSerialization

Be warned though that enabling serialization support for these unsafe classes makes your application vulnerable to known exploits and you must ensure that your application does not de-serialize objects from untrusted sources.