Johnzon is keeping the reference for map/values from JsonObjectBuilder.

final JsonObjectBuilder jsonObjectBuilder = Json.createObjectBuilder();
final JsonArrayBuilder jsonArrayBuilder = Json.createArrayBuilder();
IntStream.range(1, 10).forEach(numer -> {
    jsonObjectBuilder.add("key", String.format("Key %d", numer)); 
    jsonObjectBuilder.add("value", String.format("Value %d", numer)); 
    jsonArrayBuilder.add(jsonObjectBuilder);
});
final String message = jsonArrayBuilder.build().toString();

[{"key":"Key 9","value":"Value 9"},{"key":"Key 9","value":"Value 9"},{"key":"Key 9","value":"Value 9"},{"key":"Key 9","value":"Value 9"},{"key":"Key 9","value":"Value 9"},{"key":"Key 9","value":"Value 9"},{"key":"Key 9","value":"Value 9"},{"key":"Key 9","value":"Value 9"},{"key":"Key 9","value":"Value 9"}]

[{"key":"Key 1","value":"Value 1"},{"key":"Key 2","value":"Value 2"},{"key":"Key 3","value":"Value 3"},{"key":"Key 4","value":"Value 4"},{"key":"Key 5","value":"Value 5"},{"key":"Key 6","value":"Value 6"},{"key":"Key 7","value":"Value 7"},{"key":"Key 8","value":"Value 8"},{"key":"Key 9","value":"Value 9"}]