adams.data.conversion.JsonToString.java Source code

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Here is the source code for adams.data.conversion.JsonToString.java

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/*
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   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 General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * JsonToString.java
 * Copyright (C) 2013 University of Waikato, Hamilton, New Zealand
 */
package adams.data.conversion;

import adams.core.io.PrettyPrintingSupporter;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonElement;
import com.google.gson.JsonParser;
import net.minidev.json.JSONAware;

/**
 <!-- globalinfo-start -->
 * Turns a JSON object&#47;array into a string.
 * <br><br>
 <!-- globalinfo-end -->
 *
 <!-- options-start -->
 * Valid options are: <br><br>
 * 
 * <pre>-D &lt;int&gt; (property: debugLevel)
 * &nbsp;&nbsp;&nbsp;The greater the number the more additional info the scheme may output to 
 * &nbsp;&nbsp;&nbsp;the console (0 = off).
 * &nbsp;&nbsp;&nbsp;default: 0
 * &nbsp;&nbsp;&nbsp;minimum: 0
 * </pre>
 * 
 <!-- options-end -->
 *
 * @author  fracpete (fracpete at waikato dot ac dot nz)
 * @version $Revision$
 */
public class JsonToString extends AbstractConversionToString implements PrettyPrintingSupporter {

    /** for serialization. */
    private static final long serialVersionUID = -468714756281370533L;

    /** whether to use pretty-printing. */
    protected boolean m_PrettyPrinting;

    /**
     * Returns a string describing the object.
     *
     * @return          a description suitable for displaying in the gui
     */
    @Override
    public String globalInfo() {
        return "Turns a JSON object/array into a string.";
    }

    /**
     * Adds options to the internal list of options.
     */
    public void defineOptions() {
        super.defineOptions();

        m_OptionManager.add("pretty-printing", "prettyPrinting", false);
    }

    /**
     * Sets whether to use pretty-printing or not.
     *
     * @param value   true if to use pretty-printing
     */
    public void setPrettyPrinting(boolean value) {
        m_PrettyPrinting = value;
        reset();
    }

    /**
     * Returns whether pretty-printing is used or not.
     *
     * @return      true if to use pretty-printing
     */
    public boolean getPrettyPrinting() {
        return m_PrettyPrinting;
    }

    /**
     * Returns the tip text for this property.
     *
     * @return       tip text for this property suitable for
     *          displaying in the GUI or for listing the options.
     */
    public String prettyPrintingTipText() {
        return "If enabled, the output is printed in a 'pretty' format.";
    }

    /**
     * Returns the class that is accepted as input.
     *
     * @return      the class
     */
    @Override
    public Class accepts() {
        return JSONAware.class;
    }

    /**
     * Performs the actual conversion.
     *
     * @return      the converted data
     * @throws Exception   if something goes wrong with the conversion
     */
    @Override
    protected Object doConvert() throws Exception {
        String result;
        Gson gson;
        JsonParser jp;
        JsonElement je;

        result = ((JSONAware) m_Input).toJSONString();

        if (m_PrettyPrinting) {
            gson = new GsonBuilder().setPrettyPrinting().create();
            jp = new JsonParser();
            je = jp.parse(result);
            result = gson.toJson(je);
        }

        return result;
    }
}