Module jakarta.json
Package jakarta.json.stream

Class JsonCollectors

  • public final class JsonCollectors
extends Object
    This class contains some implementations of java.util.stream.Collector for accumulating JsonValues into JsonArray and JsonObject.
    Since:
    1.1

    • Method Detail

      • toJsonArray

        public static Collector<JsonValue,​JsonArrayBuilder,​JsonArray> toJsonArray()
        Constructs a java.util.stream.Collector that accumulates the input JsonValue elements into a JsonArray.
        Returns:
        the constructed Collector

      • toJsonObject

        public static Collector<JsonValue,​JsonObjectBuilder,​JsonObject> toJsonObject​(Function<JsonValue,​String> keyMapper,
                                                                                         Function<JsonValue,​JsonValue> valueMapper)
        Constructs a java.util.stream.Collector that accumulates the input JsonValue elements into a JsonObject. The name/value pairs of the JsonObject are computed by applying the provided mapping functions.
        Parameters:
        keyMapper - a mapping function to produce names.
        valueMapper - a mapping function to produce values
        Returns:
        the constructed Collector

      • groupingBy

        public static <T extends JsonArrayBuilder> Collector<JsonValue,​Map<String,​T>,​JsonObject> groupingBy​(Function<JsonValue,​String> classifier,
                                                                                                                      Collector<JsonValue,​T,​JsonArray> downstream)
        Constructs a java.util.stream.Collector that implements a "group by" operation on the input JsonValue elements. A classifier function maps the input JsonValues to keys, and the JsonValues are partitioned into groups according to the value of the key. A reduction operation is performed on the JsonValues in each group, using the downstream Collector. For each group, the key and the results of the reduction operation become the name/value pairs of the resultant JsonObject.
        Type Parameters:
        T - the intermediate accumulation JsonArrayBuilder of the downstream collector
        Parameters:
        classifier - a function mapping the input JsonValues to a String, producing keys
        downstream - a Collector that implements a reduction operation on the JsonValues in each group.
        Returns:
        the constructed Collector

      • groupingBy

        public static Collector<JsonValue,​Map<String,​JsonArrayBuilder>,​JsonObject> groupingBy​(Function<JsonValue,​String> classifier)
        Constructs a java.util.stream.Collector that implements a "group by" operation on the input JsonValue elements. A classifier function maps the input JsonValues to keys, and the JsonValues are partitioned into groups according to the value of the key. The JsonValues in each group are added to a JsonArray. The key and the JsonArray in each group becomes the name/value pair of the resultant JsonObject.
        Parameters:
        classifier - a function mapping the input JsonValues to a String, producing keys
        Returns:
        the constructed Collector