org.hibernate.transform.AliasToBeanConstructorResultTransformer.java Source code

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Here is the source code for org.hibernate.transform.AliasToBeanConstructorResultTransformer.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.lang.reflect.Constructor;
import java.util.List;

import org.hibernate.QueryException;

/**
 * Wraps the tuples in a constructor call.
 *
 * todo : why Alias* in the name???
 */
public class AliasToBeanConstructorResultTransformer implements ResultTransformer {

    private final Constructor constructor;

    /**
     * Instantiates a AliasToBeanConstructorResultTransformer.
     *
     * @param constructor The contructor in which to wrap the tuples.
     */
    public AliasToBeanConstructorResultTransformer(Constructor constructor) {
        this.constructor = constructor;
    }

    /**
     * Wrap the incoming tuples in a call to our configured constructor.
     */
    @Override
    public Object transformTuple(Object[] tuple, String[] aliases) {
        try {
            return constructor.newInstance(tuple);
        } catch (Exception e) {
            throw new QueryException(
                    "could not instantiate class [" + constructor.getDeclaringClass().getName() + "] from tuple",
                    e);
        }
    }

    @Override
    public List transformList(List collection) {
        return collection;
    }

    /**
     * Define our hashCode by our defined constructor's hasCode.
     *
     * @return Our defined ctor hashCode
     */
    @Override
    public int hashCode() {
        return constructor.hashCode();
    }

    /**
     * 2 AliasToBeanConstructorResultTransformer are considered equal if they have the same
     * defined constructor.
     *
     * @param other The other instance to check for equality.
     * @return True if both have the same defined constuctor; false otherwise.
     */
    @Override
    public boolean equals(Object other) {
        return other instanceof AliasToBeanConstructorResultTransformer
                && constructor.equals(((AliasToBeanConstructorResultTransformer) other).constructor);
    }
}