de.hybris.platform.patches.utils

Class PermutationUtils

java.lang.Object

de.hybris.platform.patches.utils.PermutationUtils

public final class PermutationUtils
extends java.lang.Object

Utility class to build permutations of given collections

Method Summary

Modifier and Type

Method and 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