jakarta.json.stream

Class JsonCollectors

java.lang.Object

jakarta.json.stream.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 Summary

Modifier and Type	Method and Description
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.
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.
static Collector<JsonValue,JsonArrayBuilder,JsonArray>	toJsonArray() Constructs a java.util.stream.Collector that accumulates the input JsonValue elements into a JsonArray.
static Collector<Map.Entry<String,JsonValue>,JsonObjectBuilder,JsonObject>	toJsonObject() Constructs a java.util.stream.Collector that accumulates the input Map.Entry<String,JsonValue> elements into a JsonObject.
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.

Methods inherited from class java.lang.Object

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

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<Map.Entry<String,JsonValue>,JsonObjectBuilder,JsonObject> toJsonObject()

Constructs a java.util.stream.Collector that accumulates the input Map.Entry<String,JsonValue> elements into a JsonObject.

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