Package de.hybris.platform.patches.utils

Class PermutationUtils

  • public final class PermutationUtils
extends java.lang.Object
    Utility class to build permutations of given collections

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static ImpexHeaderOption[][] permutate​(ImpexHeaderOption[][] source)
      This method creates all permutations of elements from different collections.
      Assume that as entry we get:
      String[][]{{"A1","A2"},{"B1"},{"C1","C2","C3"},{"D1","D2","D3","D4"}}
      In result we would like to have all possible 4 elements combinations that contains one element with A prefix, one with B, one with C and one with D.
      In result there will be 2*1*3*4 elements = 24 each of length 4
      Finally result for example above will be:
      [A1, B1, C1, D1], [A2, B1, C1, D1],
      [A1, B1, C2, D1], [A2, B1, C2, D1],
      [A1, B1, C3, D1], [A2, B1, C3, D1],
      [A1, B1, C1, D2], [A2, B1, C1, D2],
      [A1, B1, C2, D2], [A2, B1, C2, D2],
      [A1, B1, C3, D2], [A2, B1, C3, D2],
      [A1, B1, C1, D3], [A2, B1, C1, D3],
      [A1, B1, C2, D3], [A2, B1, C2, D3],
      [A1, B1, C3, D3], [A2, B1, C3, D3],
      [A1, B1, C1, D4], [A2, B1, C1, D4],
      [A1, B1, C2, D4], [A2, B1, C2, D4],
      [A1, B1, C3, D4], [A2, B1, C3, D4]

      Idea behind the code is to iterate over all possible permutations (so in example above from 0 to 23) - loop A.
      then iterate over elements that should be in this permutation (so in example above 0-3) - loop B.
      then fill in in target (result) proper element.

      • Methods inherited from class java.lang.Object

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

    • Method Detail

      • permutate

        public static ImpexHeaderOption[][] permutate​(ImpexHeaderOption[][] source)
        This method creates all permutations of elements from different collections.
        Assume that as entry we get:
        String[][]{{"A1","A2"},{"B1"},{"C1","C2","C3"},{"D1","D2","D3","D4"}}
        In result we would like to have all possible 4 elements combinations that contains one element with A prefix, one with B, one with C and one with D.
        In result there will be 2*1*3*4 elements = 24 each of length 4
        Finally result for example above will be:
        [A1, B1, C1, D1], [A2, B1, C1, D1],
        [A1, B1, C2, D1], [A2, B1, C2, D1],
        [A1, B1, C3, D1], [A2, B1, C3, D1],
        [A1, B1, C1, D2], [A2, B1, C1, D2],
        [A1, B1, C2, D2], [A2, B1, C2, D2],
        [A1, B1, C3, D2], [A2, B1, C3, D2],
        [A1, B1, C1, D3], [A2, B1, C1, D3],
        [A1, B1, C2, D3], [A2, B1, C2, D3],
        [A1, B1, C3, D3], [A2, B1, C3, D3],
        [A1, B1, C1, D4], [A2, B1, C1, D4],
        [A1, B1, C2, D4], [A2, B1, C2, D4],
        [A1, B1, C3, D4], [A2, B1, C3, D4]

        Idea behind the code is to iterate over all possible permutations (so in example above from 0 to 23) - loop A.
        then iterate over elements that should be in this permutation (so in example above 0-3) - loop B.
        then fill in in target (result) proper element.
        Parameters:
        source - source array
        Returns:
        null if source is null, otherwise proper permutation