org.dominokit.jackson.JsonDeserializer Maven / Gradle / Ivy
/*
* Copyright 2013 Nicolas Morel
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.dominokit.jackson;
import org.dominokit.jackson.exception.JsonDeserializationException;
import org.dominokit.jackson.stream.JsonReader;
import org.dominokit.jackson.stream.JsonToken;
/**
* Base class for all the deserializer. It handles null values and exceptions. The rest is delegated
* to implementations.
*/
public abstract class JsonDeserializer {
/**
* Deserializes a JSON input into an object.
*
* @param reader {@link org.dominokit.jackson.stream.JsonReader} used to read the JSON input
* @param ctx Context for the full deserialization process
* @return the deserialized object
* @throws org.dominokit.jackson.exception.JsonDeserializationException if an error occurs during
* the deserialization
*/
public T deserialize(JsonReader reader, JsonDeserializationContext ctx)
throws JsonDeserializationException {
return deserialize(reader, ctx, ctx.defaultParameters());
}
/**
* Deserializes a JSON input into an object.
*
* @param reader {@link org.dominokit.jackson.stream.JsonReader} used to read the JSON input
* @param ctx Context for the full deserialization process
* @param params Parameters for this deserialization
* @return the deserialized object
* @throws org.dominokit.jackson.exception.JsonDeserializationException if an error occurs during
* the deserialization
*/
public T deserialize(
JsonReader reader, JsonDeserializationContext ctx, JsonDeserializerParameters params)
throws JsonDeserializationException {
if (JsonToken.NULL.equals(reader.peek())) {
return deserializeNullValue(reader, ctx, params);
}
return doDeserialize(reader, ctx, params);
}
/**
* Deserialize the null value. This method allows children to override the default behaviour.
*
* @param reader {@link org.dominokit.jackson.stream.JsonReader} used to read the JSON input
* @param ctx Context for the full deserialization process
* @param params Parameters for this deserialization
* @return the deserialized object
*/
protected T deserializeNullValue(
JsonReader reader, JsonDeserializationContext ctx, JsonDeserializerParameters params) {
reader.skipValue();
return null;
}
/**
* Deserializes a non-null JSON input into an object.
*
* @param reader {@link org.dominokit.jackson.stream.JsonReader} used to read the JSON input
* @param ctx Context for the full deserialization process
* @param params Parameters for this deserialization
* @return the deserialized object
*/
protected abstract T doDeserialize(
JsonReader reader, JsonDeserializationContext ctx, JsonDeserializerParameters params);
/**
* Set the back reference.
*
* @param referenceName name of the reference
* @param reference reference to set
* @param value value to set the reference to.
* @param ctx Context for the full deserialization process
*/
public void setBackReference(
String referenceName, Object reference, T value, JsonDeserializationContext ctx) {
throw new JsonDeserializationException(
"Cannot set a back reference to the type managed by this deserializer");
}
}