Package org.apache.commons.collections4.functors

Class SwitchClosure<E>

java.lang.Object

org.apache.commons.collections4.functors.SwitchClosure<E>

All Implemented Interfaces:

Serializable, Closure<E>

public class SwitchClosure<E>
extends Object
implements Closure<E>, Serializable

Closure implementation calls the closure whose predicate returns true, like a switch statement.

Since:

3.0

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
SwitchClosure(Predicate<? super E>[] predicates, Closure<? super E>[] closures, Closure<? super E> defaultClosure)	Constructor that performs no validation.

Method Summary

Modifier and Type	Method	Description
void	execute(E input)	Executes the closure whose matching predicate returns true
Closure<? super E>[]	getClosures()	Gets the closures.
Closure<? super E>	getDefaultClosure()	Gets the default closure.
Predicate<? super E>[]	getPredicates()	Gets the predicates.
static <E> Closure<E>	switchClosure(Map<Predicate<E>,Closure<E>> predicatesAndClosures)	Create a new Closure that calls one of the closures depending on the predicates.
static <E> Closure<E>	switchClosure(Predicate<? super E>[] predicates, Closure<? super E>[] closures, Closure<? super E> defaultClosure)	Factory method that performs validation and copies the parameter arrays.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

SwitchClosure

public SwitchClosure(Predicate<? super E>[] predicates,
 Closure<? super E>[] closures,
 Closure<? super E> defaultClosure)

Constructor that performs no validation. Use switchClosure if you want that.

Parameters:

predicates - array of predicates, cloned, no nulls

closures - matching array of closures, cloned, no nulls

defaultClosure - the closure to use if no match, null means nop

Method Details

switchClosure

public static <E> Closure<E> switchClosure(Map<Predicate<E>,Closure<E>> predicatesAndClosures)

Create a new Closure that calls one of the closures depending on the predicates.

The Map consists of Predicate keys and Closure values. A closure is called if its matching predicate returns true. Each predicate is evaluated until one returns true. If no predicates evaluate to true, the default closure is called. The default closure is set in the map with a null key. The ordering is that of the iterator() method on the entryset collection of the map.

Type Parameters:

E - the type that the closure acts on

Parameters:

predicatesAndClosures - a map of predicates to closures

Returns:

the switch closure

Throws:

NullPointerException - if the map is null

NullPointerException - if any closure in the map is null

ClassCastException - if the map elements are of the wrong type

switchClosure

public static <E> Closure<E> switchClosure(Predicate<? super E>[] predicates,
 Closure<? super E>[] closures,
 Closure<? super E> defaultClosure)

Factory method that performs validation and copies the parameter arrays.

Type Parameters:

E - the type that the closure acts on

Parameters:

predicates - array of predicates, cloned, no nulls

closures - matching array of closures, cloned, no nulls

defaultClosure - the closure to use if no match, null means nop

Returns:

the chained closure

Throws:

NullPointerException - if array is null

NullPointerException - if any element in the array is null

IllegalArgumentException - if the array lengths of predicates and closures do not match

execute

public void execute(E input)

Executes the closure whose matching predicate returns true

Specified by:

execute in interface Closure<E>

Parameters:

input - the input object

getClosures

public Closure<? super E>[] getClosures()

Gets the closures.

Returns:

a copy of the closures

Since:

3.1

getDefaultClosure

public Closure<? super E> getDefaultClosure()

Gets the default closure.

Returns:

the default closure

Since:

3.1

getPredicates

public Predicate<? super E>[] getPredicates()

Gets the predicates.

Returns:

a copy of the predicates

Since:

3.1