javax.json.bind.serializer.JsonbDeserializer Maven / Gradle / Ivy
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package javax.json.bind.serializer;
import javax.json.stream.JsonParser;
import java.lang.reflect.Type;
/**
* Interface representing a custom deserializer for a given type. It provides a low-level API for java object
* deserialization from JSON stream using {@link JsonParser}. Unlike {@link javax.json.bind.adapter.JsonbAdapter},
* which acts more as converter from one java type to another, deserializer provides more fine grained control over
* deserialization process.
*
* {@link DeserializationContext} acts as JSONB runtime, able to deserialize any java object provided.
*
* Sample of custom Deserializer:
*
* class Box {
* public BoxInner boxInnerObject;
* public String name;
* }
*
* BoxDeserializer implements JsonbDeserializer<Box> {
* public Box deserialize(JsonParser parser, DeserializationContext ctx, Type rtType) {
* Box = new Box();
*
* while (parser.hasNext()) {
* Event event = parser.next();
*
* if (event == JsonParser.Event.KEY_NAME && parser.getString().equals("boxInnerObject") {
* // Deserialize inner object
* box.boxInnerObject = ctx.deserialize(BoxInner.class, jsonParser);
*
* } else if (event == JsonParser.Event.KEY_NAME && parser.getString().equals("name") {
* // Deserialize name property
* parser.next(); // move to VALUE
* box.name = parser.getString();
* }
* }
*
* return box;
* }
* }
*
*
* Deserializers are registered using {@link javax.json.bind.JsonbConfig#withDeserializers(JsonbDeserializer[])}
* method or using {@link javax.json.bind.annotation.JsonbTypeDeserializer} annotation on type.
*
* @param Type to bind deserializer for.
* @see javax.json.bind.JsonbConfig
* @see javax.json.bind.annotation.JsonbTypeDeserializer
* @see JsonbSerializer
* @see javax.json.bind.adapter.JsonbAdapter
* @since JSON Binding 1.0
*/
public interface JsonbDeserializer {
/**
* Deserialize JSON stream into object.
*
* @param parser
* Json parser.
* @param ctx
* Deserialization context.
* @param rtType
* Type of returned object.
* @return Deserialized instance.
*/
T deserialize(JsonParser parser, DeserializationContext ctx, Type rtType);
}