org.dominokit.jackson.ser.CollectionJsonSerializer Maven / Gradle / Ivy
/*
* Copyright 2015 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.ser;
import java.util.Collection;
import org.dominokit.jackson.JsonSerializationContext;
import org.dominokit.jackson.JsonSerializer;
import org.dominokit.jackson.JsonSerializerParameters;
import org.dominokit.jackson.stream.JsonWriter;
/**
* Default {@link org.dominokit.jackson.JsonSerializer} implementation for {@link
* java.util.Collection}.
*
* @param Type of the elements inside the {@link java.util.Collection}
*/
public class CollectionJsonSerializer, T> extends JsonSerializer {
/**
* newInstance
*
* @param serializer {@link org.dominokit.jackson.JsonSerializer} used to serialize the objects
* inside the {@link java.util.Collection}.
* @param Type of the {@link Collection}
* @return a new instance of {@link org.dominokit.jackson.ser.CollectionJsonSerializer}
*/
public static > CollectionJsonSerializer newInstance(
JsonSerializer serializer) {
return new CollectionJsonSerializer(serializer);
}
protected final JsonSerializer serializer;
/**
* Constructor for CollectionJsonSerializer.
*
* @param serializer {@link org.dominokit.jackson.JsonSerializer} used to serialize the objects
* inside the {@link java.util.Collection}.
*/
protected CollectionJsonSerializer(JsonSerializer serializer) {
if (null == serializer) {
throw new IllegalArgumentException("serializer cannot be null");
}
this.serializer = serializer;
}
/** {@inheritDoc} */
@Override
protected boolean isEmpty(C value) {
return null == value || value.isEmpty();
}
/** {@inheritDoc} */
@Override
public void doSerialize(
JsonWriter writer, C values, JsonSerializationContext ctx, JsonSerializerParameters params) {
if (values.isEmpty()) {
if (ctx.isWriteEmptyJsonArrays()) {
writer.beginArray();
writer.endArray();
} else {
writer.cancelName();
}
return;
}
if (ctx.isWriteSingleElemArraysUnwrapped() && values.size() == 1) {
// there is only one element, we write it directly
serializer.serialize(writer, values.iterator().next(), ctx, params);
} else {
writer.beginArray();
values.forEach(value -> serializer.serialize(writer, value, ctx, params));
writer.endArray();
}
}
}