ddf.catalog.transformer.csv.MetacardIterator.java Source code

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Here is the source code for ddf.catalog.transformer.csv.MetacardIterator.java

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/*
 * 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.transformer.csv;

import ddf.catalog.data.Attribute;
import ddf.catalog.data.AttributeDescriptor;
import ddf.catalog.data.Metacard;
import java.io.Serializable;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
import org.apache.commons.lang3.StringUtils;

/**
 * An implementation of java.util.Iterator which iterates over Metacard attribute values.
 *
 * @see java.util.Iterator
 */
class MetacardIterator implements Iterator<Serializable> {
    private static final String MULTIVALUE_DELIMITER = "\n";

    private List<AttributeDescriptor> attributeDescriptorList;

    private Metacard metacard;

    private int index;

    /**
     * @param metacard the metacard to be iterated over.
     * @param attributeDescriptorList the list of attributeDescriptors used to determine which
     *     metacard attributes to return.
     */
    MetacardIterator(final Metacard metacard, final List<AttributeDescriptor> attributeDescriptorList) {
        this.metacard = metacard;
        this.attributeDescriptorList = Collections.unmodifiableList(attributeDescriptorList);
        this.index = 0;
    }

    /** {@inheritDoc} */
    @Override
    public boolean hasNext() {
        return this.attributeDescriptorList.size() > index;
    }

    /** {@inheritDoc} */
    @Override
    public Serializable next() {
        if (!this.hasNext()) {
            throw new NoSuchElementException();
        }

        AttributeDescriptor attributeDescriptor = this.attributeDescriptorList.get(index);
        Attribute attribute = metacard.getAttribute(attributeDescriptor.getName());
        index++;

        if (attribute != null) {
            if (attributeDescriptor.isMultiValued()) {
                return StringUtils.join(attribute.getValues(), MULTIVALUE_DELIMITER);
            } else {
                return attribute.getValue();
            }
        }

        return "";
    }
}