org.apache.commons.collections.functors

Class SwitchClosure

public class SwitchClosure extends Object implements Closure, Serializable

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

Since: Commons Collections 3.0

Version: $Revision: 348444 $ $Date: 2005-11-23 14:06:56 +0000 (Wed, 23 Nov 2005) $

Author: Stephen Colebourne

Constructor Summary
SwitchClosure(Predicate[] predicates, Closure[] closures, Closure defaultClosure)
Constructor that performs no validation.
Method Summary
voidexecute(Object input)
Executes the closure whose matching predicate returns true
Closure[]getClosures()
Gets the closures, do not modify the array.
ClosuregetDefaultClosure()
Gets the default closure.
static ClosuregetInstance(Predicate[] predicates, Closure[] closures, Closure defaultClosure)
Factory method that performs validation and copies the parameter arrays.
static ClosuregetInstance(Map predicatesAndClosures)
Create a new Closure that calls one of the closures depending on the predicates.
Predicate[]getPredicates()
Gets the predicates, do not modify the array.

Constructor Detail

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 Detail

execute

public void execute(Object input)
Executes the closure whose matching predicate returns true

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(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

Throws: IllegalArgumentException if array is null IllegalArgumentException if any element in the array is null

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

Throws: IllegalArgumentException if the map is null IllegalArgumentException if any closure in the map is null ClassCastException if the map elements are of the wrong type

getPredicates

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

Returns: the predicates

Since: Commons Collections 3.1

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