ddf.catalog.transformer.csv.common.CsvTransformer.java Source code

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Here is the source code for ddf.catalog.transformer.csv.common.CsvTransformer.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.common;

import static java.util.stream.Collectors.toList;
import static java.util.stream.Collectors.toSet;

import ddf.catalog.data.AttributeDescriptor;
import ddf.catalog.data.AttributeType;
import ddf.catalog.data.BinaryContent;
import ddf.catalog.data.Metacard;
import ddf.catalog.data.MetacardType;
import ddf.catalog.data.impl.BinaryContentImpl;
import ddf.catalog.transform.CatalogTransformerException;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.Serializable;
import java.nio.charset.StandardCharsets;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import javax.activation.MimeType;
import javax.activation.MimeTypeParseException;
import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVPrinter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Common Library used to transform {@link Metacard}s into CSV text.
 *
 * @see MetacardTransformer
 * @see Metacard
 * @see QueryResponseTransformer
 * @see QueryResponse
 * @see Attribute
 */
public class CsvTransformer {

    private static final Logger LOGGER = LoggerFactory.getLogger(CsvTransformer.class);

    private static final MimeType CSV_MIME_TYPE;

    static {
        try {
            CSV_MIME_TYPE = new MimeType("text/csv");
        } catch (MimeTypeParseException e) {
            throw new ExceptionInInitializerError(e);
        }
    }

    public static BinaryContent createResponse(final Appendable csv) {
        InputStream inputStream = new ByteArrayInputStream(csv.toString().getBytes(StandardCharsets.UTF_8));
        return new BinaryContentImpl(inputStream, CSV_MIME_TYPE);
    }

    public static Appendable writeMetacardsToCsv(final List<Metacard> metacards,
            final List<AttributeDescriptor> orderedAttributeDescriptors, final Map<String, String> aliasMap)
            throws CatalogTransformerException {
        StringBuilder stringBuilder = new StringBuilder();

        try {
            CSVPrinter csvPrinter = new CSVPrinter(stringBuilder, CSVFormat.RFC4180);
            printColumnHeaders(csvPrinter, orderedAttributeDescriptors, aliasMap);

            metacards.forEach(metacard -> printMetacard(csvPrinter, metacard, orderedAttributeDescriptors));

            return csvPrinter.getOut();
        } catch (IOException ioe) {
            throw new CatalogTransformerException(ioe);
        }
    }

    private static boolean attributeNotBinary(AttributeDescriptor attributeDescriptor) {
        return !AttributeType.AttributeFormat.BINARY.equals(attributeDescriptor.getType().getAttributeFormat());
    }

    private static boolean attributeNotObject(AttributeDescriptor attributeDescriptor) {
        return !AttributeType.AttributeFormat.OBJECT.equals(attributeDescriptor.getType().getAttributeFormat());
    }

    private static void printMetacard(final CSVPrinter csvPrinter, final Metacard metacard,
            final List<AttributeDescriptor> orderedAttributeDescriptors) {
        Iterator<Serializable> metacardIterator = new MetacardIterator(metacard, orderedAttributeDescriptors);
        printMetacardData(csvPrinter, metacardIterator, metacard);
    }

    private static void printColumnHeaders(final CSVPrinter csvPrinter,
            final List<AttributeDescriptor> orderedAttributeDescriptors, final Map<String, String> aliasMap) {
        Iterator<String> columnHeaderIterator = new ColumnHeaderIterator(orderedAttributeDescriptors, aliasMap);
        printHeaders(csvPrinter, columnHeaderIterator);
    }

    private static void printHeaders(final CSVPrinter csvPrinter, final Iterator iterator) {
        try {
            csvPrinter.printRecord(() -> iterator);
        } catch (IOException ioe) {
            LOGGER.debug("Failed to print the CSV header data.", ioe);
        }
    }

    private static void printMetacardData(final CSVPrinter csvPrinter, final Iterator iterator, Metacard metacard) {
        try {
            csvPrinter.printRecord(() -> iterator);
        } catch (IOException ioe) {
            LOGGER.debug("Failed to print the CSV data for metacard with id: {}", metacard.getId(), ioe);
        }
    }

    public static List<AttributeDescriptor> sortAttributes(final Set<AttributeDescriptor> attributeSet,
            final List<String> attributeOrder) {
        CsvAttributeDescriptorComparator attributeComparator = new CsvAttributeDescriptorComparator(attributeOrder);

        return attributeSet.stream().sorted(attributeComparator).collect(toList());
    }

    /**
     * Given a list of {@link Metacard}s, returns a set of {@link AttributeDescriptor}s that contains
     * all attributes that exist on the given metacard types. Object and Binary types are excluded
     *
     * @param metacards List of metacards from which to extract attribute descriptors
     * @return a Set of {@AttributeDescriptor}s that are on each metacard
     */
    public static Set<AttributeDescriptor> getAllCsvAttributeDescriptors(final List<Metacard> metacards) {

        return metacards.stream().filter(Objects::nonNull).map(Metacard::getMetacardType)
                .map(MetacardType::getAttributeDescriptors).flatMap(Set::stream)
                .filter(CsvTransformer::attributeNotBinary).filter(CsvTransformer::attributeNotObject)
                .collect(toSet());
    }

    /**
     * Given a list of {@link Metacard}s and a string set of requested attributes, returns a set of
     * {@link AttributeDescriptor}s containing the requested attributes.
     */
    public static Set<AttributeDescriptor> getOnlyRequestedAttributes(final List<Metacard> metacards,
            final Set<String> requestedAttributes) {
        final Set<AttributeDescriptor> attributes = getAllCsvAttributeDescriptors(metacards);

        // Filter out attributes not requested.
        attributes.removeIf(attrDesc -> !requestedAttributes.contains(attrDesc.getName()));

        return attributes;
    }
}