CollectionUtil (liquibase 4.20.0 API)

public class CollectionUtil
extends Object

Constructors
Constructor and Description
`CollectionUtil()`

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static <T> List<T>`	`createIfNull(List<T> currentValue)` Returns passed currentValue if it is not null and creates a new ArrayList if it is null.
`static <T,E> Map<T,E>`	`createIfNull(Map<T,E> currentValue)` Returns a new empty map if the passed map is null.
`static <T> Set<T>`	`createIfNull(Set<T> currentValue)` Returns a new empty set if the passed set is null.
`static <T> T[]`	`createIfNull(T[] arguments)` Returns a new empty array if the passed array is null.
`static Map<String,Object>`	`flatten(Map<String,Object> map)` Converts a set of nested maps (like from yaml/json) into a flat map with dot-separated properties
`static <T> List<Map<String,T>>`	`permutations(Map<String,List<T>> parameterValues)`
`static <T> Set<Set<T>>`	`powerSet(Collection<T> originalSet)`

public static <T> Set<Set<T>> powerSet(Collection<T> originalSet)

public static <T> List<Map<String,T>> permutations(Map<String,List<T>> parameterValues)

createIfNull
```
public static <T> T[] createIfNull(T[] arguments)
```
Returns a new empty array if the passed array is null.

public static <T> Set<T> createIfNull(Set<T> currentValue)

Returns a new empty set if the passed set is null.

public static <T,E> Map<T,E> createIfNull(Map<T,E> currentValue)

Returns a new empty map if the passed map is null.

flatten
```
public static Map<String,Object> flatten(Map<String,Object> map)
```
Converts a set of nested maps (like from yaml/json) into a flat map with dot-separated properties

Class CollectionUtil