io.micronaut.jackson.serialize.OptionalValuesSerializer Maven / Gradle / Ivy
/*
* Copyright 2017-2020 original authors
*
* 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 io.micronaut.jackson.serialize;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import io.micronaut.core.value.OptionalMultiValues;
import io.micronaut.core.value.OptionalValues;
import javax.inject.Singleton;
import java.io.IOException;
import java.util.List;
import java.util.Optional;
/**
* A Jackson Serializer for {@link OptionalValues}.
*
* @author Graeme Rocher
* @since 1.0
*/
@Singleton
public class OptionalValuesSerializer extends JsonSerializer> {
@Override
public boolean isEmpty(SerializerProvider provider, OptionalValues value) {
return value.isEmpty();
}
@Override
public void serialize(OptionalValues value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
gen.writeStartObject();
for (CharSequence key : value) {
Optional opt = value.get(key);
if (opt.isPresent()) {
String fieldName = key.toString();
gen.writeFieldName(fieldName);
Object v = opt.get();
if (value instanceof OptionalMultiValues) {
List list = (List) v;
if (list.size() == 1) {
gen.writeObject(list.get(0));
} else {
gen.writeObject(list);
}
} else {
gen.writeObject(v);
}
}
}
gen.writeEndObject();
}
}