de.dfki.asr.compass.rest.serialization.AbstractIDListDeserializer.java Source code

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Here is the source code for de.dfki.asr.compass.rest.serialization.AbstractIDListDeserializer.java

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/*
 * This file is part of COMPASS. It is subject to the license terms in
 * the LICENSE file found in the top-level directory of this distribution.
 * (Also available at http://www.apache.org/licenses/LICENSE-2.0.txt)
 * You may not use this file except in compliance with the License.
 */
package de.dfki.asr.compass.rest.serialization;

import de.dfki.asr.compass.rest.util.CDIInjector;
import de.dfki.asr.compass.business.exception.EntityNotFoundException;
import java.io.IOException;
import java.util.LinkedList;
import java.util.List;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.ObjectCodec;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;
import de.dfki.asr.compass.model.AbstractCompassEntity;

/**
 * Base class to deserialize a list of IDs to their model instances.
 *
 * @param <EntityType> the type of model class to deserialize an ID to
 */
public abstract class AbstractIDListDeserializer<EntityType extends AbstractCompassEntity>
        extends JsonDeserializer<List<EntityType>> {

    public AbstractIDListDeserializer() {
        new CDIInjector<AbstractIDListDeserializer>().inject(this);
    }

    @Override
    public List<EntityType> deserialize(final JsonParser jp, final DeserializationContext dc)
            throws IOException, JsonProcessingException {
        ObjectCodec oc = jp.getCodec();
        List<Long> ids = oc.readValue(jp, new TypeReference<List<Long>>() {
        });
        List<EntityType> refs = new LinkedList<>();
        try {
            for (Long id : ids) {
                refs.add(referenceById(id));
            }
            return refs;
        } catch (EntityNotFoundException e) {
            throw new IOException("Cannot load from Database", e);
        }
    }

    protected abstract EntityType referenceById(long id) throws EntityNotFoundException;
}