org.loklak.api.vis.PieChartServlet.java Source code

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Here is the source code for org.loklak.api.vis.PieChartServlet.java

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/**
 *  PieChartServlet
 *  Copyright 01.08.2016 by Sudheesh Singanamalla, @sudheesh001
 *
 *  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 program in the file lgpl21.txt
 *  If not, see <http://www.gnu.org/licenses/>.
 */

package org.loklak.api.vis;

import java.awt.BasicStroke;
import java.awt.Color;
import java.io.IOException;
import java.io.OutputStream;
import java.util.*;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.json.JSONObject;
import org.loklak.server.Query;
import org.loklak.http.RemoteAccess;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.data.general.DefaultPieDataset;

/*
 * Sample Queries
 * ==============
 * Every json to be visualized should be a key:value pair object
 * {"ford":"17.272992","toyota":"27.272992","renault":"47.272992"}
 * Note that the floatvalues should be strings and stringified
 * Query: http://127.0.0.1:9000/vis/piechart.png?data={%22ford%22:%2217.272992%22,%22toyota%22:%2227.272992%22,%22renault%22:%2247.272992%22}&width=1000&height=1000&legend=true&tooltip=false
 */

public class PieChartServlet extends HttpServlet {

    public static final long serialVersionUID = 1L;

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {

        Query post = RemoteAccess.evaluate(request);

        // Get the json data to visualize as a key value pair of data=

        if (post.isDoS_blackout()) {
            response.sendError(503, "Your request frequency is too high");
            return;
        }

        // Get the data json string passed as stream parameter
        String data = post.get("data", "");
        String legendBitString = post.get("legend", "");
        String tooltipBitString = post.get("tooltip", "");
        String widthString = post.get("width", "");
        String heightString = post.get("height", "");
        boolean legendBit = true;
        boolean tooltipBit = false;

        int width = 500;
        int height = 500;

        if ("".equals(legendBitString) || "false".equals(legendBitString)) {
            legendBit = true;
        } else {
            legendBit = false;
        }

        if ("".equals(tooltipBitString) || !"true".equals(tooltipBitString)) {
            tooltipBit = false;
        } else {
            tooltipBit = true;
        }

        if (!"".equals(widthString)) {
            width = Integer.parseInt(widthString);
        }

        if (!"".equals(heightString)) {
            height = Integer.parseInt(heightString);
        }

        JSONObject json = new JSONObject(data);

        response.setContentType("image/png");

        OutputStream outputStream = response.getOutputStream();

        JFreeChart chart = getChart(json, legendBit, tooltipBit);
        ChartUtilities.writeChartAsPNG(outputStream, chart, width, height);
    }

    public JFreeChart getChart(JSONObject jsonData, boolean legendBit, boolean tooltipBit) {
        DefaultPieDataset dataset = new DefaultPieDataset();
        Iterator iter = jsonData.keys();

        while (iter.hasNext()) {
            String keyData = (String) iter.next();
            Float value = Float.parseFloat(jsonData.getString(keyData));
            dataset.setValue(keyData, value);
        }

        boolean legend = legendBit;
        boolean tooltips = tooltipBit;
        boolean urls = false;

        JFreeChart chart = ChartFactory.createPieChart("Loklak Visualizes - PieChart", dataset, legend, tooltips,
                urls);

        chart.setBorderPaint(Color.BLACK);
        chart.setBorderStroke(new BasicStroke(5.0f));
        chart.setBorderVisible(true);

        return chart;
    }
}