Package org.apache.commons.collections.functors

Class SwitchClosure

  • All Implemented Interfaces:
    Serializable, Closure
    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: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
    Author:
    Stephen Colebourne
    See Also:
    Serialized Form

    • 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

      • 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

      • 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

      • getPredicates

        public Predicate[] getPredicates()
        Gets the predicates, do not modify the array.
        Returns:
        the predicates
        Since:
        Commons Collections 3.1

      • 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