InputTransformer.java

/**
 * Copyright (c) Codice Foundation
 * <p>
 * This is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser
 * General Public License as published by the Free Software Foundation, either version 3 of the
 * License, or any later version.
 * <p>
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details. A copy of the GNU Lesser General Public License
 * is distributed along with this program and can be found at
 * <http://www.gnu.org/licenses/lgpl.html>.
 */
package ddf.catalog.transform;

import java.io.IOException;
import java.io.InputStream;

import ddf.catalog.data.Metacard;

/**
 * An InputTransformer has the purpose of creating a {@link Metacard} from a given
 * {@code InputStream}. Alternatively a {@link Metacard} implementation's constructor can be used to
 * create {@link Metacard}s.
 * <p>
 * <b>Implementations of this interface <em>must</em>:</b>
 * <ul>
 * <li/>Register with the OSGi Service Registry using the {@link InputTransformer} interface
 * <li/>Include a Service property with name "id" ({@link ddf.catalog.Constants#SERVICE_ID}) and a
 * {@code String} value uniquely identifying the particular implementation
 * </ul>
 *
 * @author ddf.isgs@lmco.com
 */
public interface InputTransformer {

    /**
     * Transforms the input into a {@link Metacard}.
     *
     * @param input
     *            the binary {@code InputStream} to transform
     * @return the generated {@link Metacard}
     * @throws IOException
     *             if an I/O exception occurs when reading the {@link InputStream}
     * @throws CatalogTransformerException
     *             if an error occurs during transformation
     */
    public Metacard transform(InputStream input) throws IOException, CatalogTransformerException;

    /**
     * Transforms the input into a {@link Metacard} and associates the id with the {@link Metacard}
     * on creation.
     *
     * @param input
     *            the binary {@code InputStream} to transform
     * @param id
     *            the attribute value for the {@link Metacard#ID} attribute that should be set in
     *            the generated {@link Metacard}
     * @return the generated {@link Metacard}
     * @throws IOException
     *             if an I/O exception occurs when reading the {@link InputStream}
     * @throws CatalogTransformerException
     *             if an error occurs during transformation
     */
    public Metacard transform(InputStream input, String id)
            throws IOException, CatalogTransformerException;

}