org.hibernate.transform.PassThroughResultTransformer.java Source code

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Here is the source code for org.hibernate.transform.PassThroughResultTransformer.java

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/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.transform;

import java.util.Arrays;
import java.util.List;

/**
 * ???
 *
 * @author max
 */
public class PassThroughResultTransformer extends BasicTransformerAdapter implements TupleSubsetResultTransformer {

    public static final PassThroughResultTransformer INSTANCE = new PassThroughResultTransformer();

    /**
     * Disallow instantiation of PassThroughResultTransformer.
     */
    private PassThroughResultTransformer() {
    }

    @Override
    public Object transformTuple(Object[] tuple, String[] aliases) {
        return tuple.length == 1 ? tuple[0] : tuple;
    }

    @Override
    public boolean isTransformedValueATupleElement(String[] aliases, int tupleLength) {
        return tupleLength == 1;
    }

    @Override
    public boolean[] includeInTransform(String[] aliases, int tupleLength) {
        boolean[] includeInTransformedResult = new boolean[tupleLength];
        Arrays.fill(includeInTransformedResult, true);
        return includeInTransformedResult;
    }

    /* package-protected */
    List untransformToTuples(List results, boolean isSingleResult) {
        // untransform only if necessary; if transformed, do it in place;
        if (isSingleResult) {
            for (int i = 0; i < results.size(); i++) {
                Object[] tuple = untransformToTuple(results.get(i), isSingleResult);
                results.set(i, tuple);
            }
        }
        return results;
    }

    /* package-protected */
    Object[] untransformToTuple(Object transformed, boolean isSingleResult) {
        return isSingleResult ? new Object[] { transformed } : (Object[]) transformed;
    }

    /**
     * Serialization hook for ensuring singleton uniqueing.
     *
     * @return The singleton instance : {@link #INSTANCE}
     */
    private Object readResolve() {
        return INSTANCE;
    }

}