Class MultiValuedToFlatMapConverter

java.lang.Object
de.xima.fc.converter.json.MultiValuedToFlatMapConverter
public class MultiValuedToFlatMapConverter extends Object
Converts between a flat map Map<String, V> with compound keys and a multivalued map Map<String, List<V>>.

The flat map uses keys in the format "key.index" to represent lists, where "key" is the base key and "index" is the zero-based index of the value in the list.

For example, the multivalued map: 

    Map.of("key", List.of("value1", "value2", "value3"));
corresponds to the flat map: 
    Map.of("key.0", "value1", "key.1", "value2", "key.2", "value3");
Since:
8.5.0

  • Method Details

    • fromFlatMap

      public static <V> Map<String,List<V>> fromFlatMap(Map<String,V> flatMap)
      Converts a flat map with compound keys into a multivalued map.
      Type Parameters:
      V - the type of values in the map.
      Parameters:
      flatMap - The flat map to convert, where keys are in the format "key.index".
      Returns:
      A multivalued map where each key maps to a list of values.

    • toFlatMap

      public static <V> Map<String,V> toFlatMap(Map<String,List<V>> multiValuedMap)
      Converts a multivalued map into a flat map with compound keys.
      Type Parameters:
      V - the type of values in the map.
      Parameters:
      multiValuedMap - The multivalued map to convert, where each key maps to a list of values.
      Returns:
      A flat map where keys are in the format "key.index".

    • toFlatMap

      public static <V> void toFlatMap(Map<String,List<V>> multiValuedMap, Map<String,V> target)
      Converts a multivalued map into a flat map with compound keys, writing the result into the provided target map.
      Type Parameters:
      V - the type of values in the map.
      Parameters:
      multiValuedMap - The multivalued map to convert, where each key maps to a list of values.
      target - The target flat map where the result will be written.