JSON-B

org.apache.johnzon:johnzon-jsonb:2.2.0

Contents

johnzon-jsonb implements the JSON-B 3.0 standard on top of the Johnzon mapper, fully reusing JSON-B as its API:

try (Jsonb jsonb = JsonbBuilder.create()) {
    String json = jsonb.toJson(myObject);
    MyObject back = jsonb.fromJson(json, MyObject.class);
}

Johnzon-specific configuration

Beyond the standard JsonbConfig properties, Johnzon wires its native configuration through these keys (more in the JohnzonBuilder class):

Property	Effect
`johnzon.interfaceImplementationMapping`	`Map<Class, Class>` mapping interfaces to implementations for deserialization.
`johnzon.use-big-decimal-for-object`	Use `BigDecimal` for untyped numbers (`Object`); `false` adjusts the type to the number size. Default `true`.
`johnzon.support-enum-container-deserialization`	Allow `EnumMap`/`EnumSet` instantiation. Default `true`.
`johnzon.attributeOrder`	`Comparator` instance sorting properties by name.
`johnzon.deduplicateObjects`	Deduplicate instances.
`johnzon.supportsPrivateAccess`	Use private constructors/methods carrying `@JsonbCreator`.
`johnzon.fail-on-unknown-properties`	Fail the mapping on unmapped properties (like `jsonb.fail-on-unknown-properties`).
`johnzon.readAttributeBeforeWrite`	Read collections before writing. This enables an “append” mode.
`johnzon.autoAdjustBuffer`	Auto-adjust internal read buffers.
`johnzon.serialize-value-filter`	Filter to skip serializing some values.
`johnzon.cdi.activated`	Toggle CDI support.
`johnzon.accessMode`	Custom access mode; can disable some JSON-B features (annotation support).
`johnzon.accessModeDelegate`	Delegate access mode used by `JsonbAccessModel`, enriching the default.
`johnzon.failOnMissingCreatorValues`	Fail when a `@JsonbCreator` misses values.
`johnzon.use-biginteger-stringadapter`	Map `BigInteger` as a string. Default `true`; set `false` for strict JSON-B 3 compliance.
`johnzon.use-bigdecimal-stringadapter`	Map `BigDecimal` as a string. Default `true`; set `false` for strict JSON-B 3 compliance.

JAX-RS provider

The module also ships a JSON-B based JAX-RS provider, org.apache.johnzon.jaxrs.jsonb.jaxrs.JsonbJaxrsProvider.

In JAX-RS 1.0 a provider could throw any exception for an empty incoming stream; JAX-RS 2.x requires a jakarta.ws.rs.core.NoContentException. To let you pick and to limit breaking changes, the provider exposes throwNoContentExceptionOnEmptyStreams; the default is derived from the available API. This behavior only works with johnzon-core.

Integration with JsonValue

JsonValueReader and JsonValueWriter map a JsonValue to a POJO and back without any I/O. Any Reader implementing Supplier<JsonStructure> or Writer implementing Consumer<JsonValue> works:

final JsonValueReader<Simple> reader = new JsonValueReader<>(
    Json.createObjectBuilder().add("value", "simple").build());
try (Jsonb jsonb = getJohnzonJsonb()) {
    final Simple simple = jsonb.fromJson(reader, SomeModel.class);
}

final JsonValueWriter writer = new JsonValueWriter();
try (Jsonb jsonb = getJohnzonJsonb()) {
    jsonb.toJson(object, writer);
}
final JsonObject jsonObject = writer.getObject();

As an experimental preview of a future specification version, org.apache.johnzon.jsonb.api.experimental.JsonbExtension maps POJOs to JsonValue and the opposite.

Next: JAX-RS