org.dominokit.jackson.deser.collection.BaseCollectionJsonDeserializer 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.deser.collection;
import java.util.Collection;
import org.dominokit.jackson.JsonDeserializationContext;
import org.dominokit.jackson.JsonDeserializer;
import org.dominokit.jackson.JsonDeserializerParameters;
import org.dominokit.jackson.stream.JsonReader;
import org.dominokit.jackson.stream.JsonToken;
/**
* Base {@link org.dominokit.jackson.JsonDeserializer} implementation for {@link
* java.util.Collection}.
*
* @param {@link java.util.Collection} type
* @param Type of the elements inside the {@link java.util.Collection}
*/
public abstract class BaseCollectionJsonDeserializer, T>
extends BaseIterableJsonDeserializer {
/**
* Constructor for BaseCollectionJsonDeserializer.
*
* @param deserializer {@link org.dominokit.jackson.JsonDeserializer} used to map the objects
* inside the {@link java.util.Collection}.
*/
public BaseCollectionJsonDeserializer(JsonDeserializer deserializer) {
super(deserializer);
}
/** {@inheritDoc} */
@Override
public C doDeserialize(
JsonReader reader, JsonDeserializationContext ctx, JsonDeserializerParameters params) {
if (JsonToken.BEGIN_ARRAY == reader.peek()) {
C result = newCollection();
reader.beginArray();
while (JsonToken.END_ARRAY != reader.peek()) {
T element = deserializer.deserialize(reader, ctx, params);
if (isNullValueAllowed() || null != element) {
result.add(element);
}
}
reader.endArray();
return result;
} else if (ctx.isAcceptSingleValueAsArray()) {
C result = newCollection();
result.add(deserializer.deserialize(reader, ctx, params));
return result;
} else {
throw ctx.traceError(
"Cannot deserialize a java.util.Collection out of " + reader.peek() + " token", reader);
}
}
/**
* Instantiates a new collection for deserialization process.
*
* @return the new collection
*/
protected abstract C newCollection();
/**
* isNullValueAllowed
*
* @return true if the collection accepts null value
*/
protected boolean isNullValueAllowed() {
return true;
}
/** {@inheritDoc} */
@Override
public void setBackReference(
String referenceName, Object reference, C value, JsonDeserializationContext ctx) {
if (null != value && !value.isEmpty()) {
for (T val : value) {
deserializer.setBackReference(referenceName, reference, val, ctx);
}
}
}
}