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
  Version:
    $Id: SwitchClosure.java 1686855 2015-06-22 13:00:27Z tn $
  See Also:
    Serialized Form

- - ### Constructor Summary

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

  - ### Method Summary

    Methods
    Modifier and Type | Method and 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 Detail

    - #### 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 Detail

    - #### 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

    - #### 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

    - #### 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

    - #### getPredicates

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

      Gets the predicates.
      Returns:
        a copy of the predicates
      Since:
        3.1

    - #### 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

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