org.kalypso.grid.AsciiGridReader.java Source code

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Here is the source code for org.kalypso.grid.AsciiGridReader.java

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/*----------------    FILE HEADER KALYPSO ------------------------------------------
 *
 *  This file is part of kalypso.
 *  Copyright (C) 2004 by:
 *
 *  Technical University Hamburg-Harburg (TUHH)
 *  Institute of River and coastal engineering
 *  Denickestrae 22
 *  21073 Hamburg, Germany
 *  http://www.tuhh.de/wb
 *
 *  and
 *
 *  Bjoernsen Consulting Engineers (BCE)
 *  Maria Trost 3
 *  56070 Koblenz, Germany
 *  http://www.bjoernsen.de
 *
 *  This library 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 2.1 of the License, or (at your option) any later version.
 *
 *  This library 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.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *  Contact:
 *
 *  E-Mail:
 *  belger@bjoernsen.de
 *  schlienger@bjoernsen.de
 *  v.doemming@tuhh.de
 *
 *  ---------------------------------------------------------------------------*/
package org.kalypso.grid;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Scanner;

import org.apache.commons.io.IOUtils;
import org.kalypso.contribs.java.lang.NumberUtils;
import org.kalypsodeegree.model.coverage.GridRange;
import org.kalypsodeegree.model.geometry.GM_Point;
import org.kalypsodeegree_impl.gml.binding.commons.RectifiedGridDomain;
import org.kalypsodeegree_impl.gml.binding.commons.RectifiedGridDomain.OffsetVector;
import org.kalypsodeegree_impl.model.cv.GridRange_Impl;
import org.kalypsodeegree_impl.model.geometry.GeometryFactory;

/**
 * Ascii-Grid Wrapper class which reads the header of an ESRI Ascii Grid<br>
 * <br>
 * Ascii-Grid Header:<br>
 * NCOLS xxx <br>
 * NROWS xxx <br>
 * XLLCENTER xxx | XLLCORNER xxx<br>
 * YLLCENTER xxx | YLLCORNER xxx <br>
 * CELLSIZE xxx<br>
 * NODATA_VALUE xxx<br>
 * 
 * @author Dirk Kuch
 */
public class AsciiGridReader {
    private String[] m_headerData;

    private String[] m_headerKeys;

    public AsciiGridReader(final URL input) throws IOException {
        parseHeader(input);
    }

    public AsciiGridReader(final Scanner scanner) throws IOException {
        readAsciiGridHeader(scanner);
    }

    private void parseHeader(final URL input) throws IOException {
        InputStream is = null;

        try {
            is = new BufferedInputStream(input.openStream());
            readAsciiGridHeader(new Scanner(is));
            is.close();
        } finally {
            IOUtils.closeQuietly(is);
        }
    }

    private void readAsciiGridHeader(final Scanner scanner) throws IOException {
        m_headerKeys = new String[6];
        m_headerData = new String[6];

        String line;

        // reading header data
        for (int i = 0; i < 6; i++) {
            line = scanner.nextLine();

            if (line.startsWith("/*")) {
                i--;
                continue;
            }

            final String[] values = line.split("\\s+");

            m_headerKeys[i] = values[0].trim();
            m_headerData[i] = values[1].trim();
        }

        if (scanner.ioException() != null)
            throw scanner.ioException();
    }

    private String getCols() {
        return m_headerData[0];
    }

    private String getRows() {
        return m_headerData[1];
    }

    private double getOriginCornerX() {
        if ("xllcorner".equals(m_headerKeys[2].toLowerCase())) {
            final double size = getCellSize() / 2.0;
            return NumberUtils.parseDouble(m_headerData[2]) + size;
        }

        if ("xllcenter".equals(m_headerKeys[2].toLowerCase()))
            return NumberUtils.parseDouble(m_headerData[2]);

        throw new UnsupportedOperationException();
    }

    private double getOriginCornerY() {
        if ("yllcorner".equals(m_headerKeys[3].toLowerCase())) {
            final double size = getCellSize() / 2.0;
            return NumberUtils.parseDouble(m_headerData[3]) - size;
        }

        if ("yllcenter".equals(m_headerKeys[3].toLowerCase()))
            return NumberUtils.parseDouble(m_headerData[3]);

        throw new UnsupportedOperationException();
    }

    public double getCellSize() {
        return NumberUtils.parseDouble(m_headerData[4]);
    }

    public String getNoDataValue() {
        return m_headerData[5];
    }

    public RectifiedGridDomain getGridDomain(final String cs) throws Exception {
        final int nCols = new Integer(getCols()).intValue();
        final int nRows = new Integer(getRows()).intValue();

        final OffsetVector offsetX = new OffsetVector(getCellSize(), 0);
        final OffsetVector offsetY = new OffsetVector(0, -getCellSize());

        final double adjustedCornerY = getOriginCornerY() + nRows * getCellSize();

        final GM_Point origin = GeometryFactory.createGM_Point(getOriginCornerX(), adjustedCornerY, cs);

        final double[] low = { 0.0, 0.0 };
        final double[] high = { nCols, nRows };
        final GridRange gridRange = new GridRange_Impl(low, high);

        return new RectifiedGridDomain(origin, offsetX, offsetY, gridRange);
    }
}