org.apache.commons.collections.functors

Class SwitchClosure

Implemented Interfaces:
Closure, Serializable

public class SwitchClosure
extends java.lang.Object
implements Closure, Serializable

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

Version:
$Revision: 1.5 $ $Date: 2004/05/16 11:47:38 $

Author:
Stephen Colebourne

Since:
Commons Collections 3.0

Constructor Summary

SwitchClosure(Predicate[] predicates, Closure[] closures, Closure defaultClosure)
Constructor that performs no validation.

Method Summary

void
execute(Object input)
Executes the closure whose matching predicate returns true
Closure[]
getClosures()
Gets the closures, do not modify the array.
Closure
getDefaultClosure()
Gets the default closure.
static Closure
getInstance(Map predicatesAndClosures)
Create a new Closure that calls one of the closures depending on the predicates.
static Closure
getInstance(Predicate[] predicates, Closure[] closures, Closure defaultClosure)
Factory method that performs validation and copies the parameter arrays.
Predicate[]
getPredicates()
Gets the predicates, do not modify the array.

Constructor Details

SwitchClosure

public SwitchClosure(Predicate[] predicates,
                     Closure[] closures,
                     Closure defaultClosure)
Constructor that performs no validation. Use getInstance if you want that.

Parameters:
predicates - array of predicates, not cloned, no nulls
closures - matching array of closures, not cloned, no nulls
defaultClosure - the closure to use if no match, null means nop

Method Details

execute

public void execute(Object input)
Executes the closure whose matching predicate returns true
Specified by:
execute in interface Closure

Parameters:
input - the input object


getClosures

public Closure[] getClosures()
Gets the closures, do not modify the array.

Returns:
the closures

Since:
Commons Collections 3.1


getDefaultClosure

public Closure getDefaultClosure()
Gets the default closure.

Returns:
the default closure

Since:
Commons Collections 3.1


getInstance

public static Closure getInstance(Map 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.

Parameters:
predicatesAndClosures - a map of predicates to closures

Returns:
the switch closure


getInstance

public static Closure getInstance(Predicate[] predicates,
                                  Closure[] closures,
                                  Closure defaultClosure)
Factory method that performs validation and copies the parameter arrays.

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


getPredicates

public Predicate[] getPredicates()
Gets the predicates, do not modify the array.

Returns:
the predicates

Since:
Commons Collections 3.1


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