org.apache.commons.collections.functors

## Class SwitchClosure

- java.lang.Object
- - org.apache.commons.collections.functors.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 Summary

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

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `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.

    - ### Methods inherited from class java.lang.Object

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

- - ### 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

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