FreeMemoryViewer.java Source code

Introduction

Here is the source code for FreeMemoryViewer.java

Source

/*
*    Giovanni Capuano <webmaster@giovannicapuano.net>
*    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/>.
*/

import org.jfree.chart.*;
import org.jfree.data.xy.*;
import org.jfree.chart.plot.*;
import org.jfree.chart.renderer.xy.XYSplineRenderer;
import java.io.*;
import javax.swing.*;

public class FreeMemoryViewer extends JFrame {
    private XYSeries used, total, free;

    public FreeMemoryViewer(String applicationTitle, String chartTitle) {
        super(applicationTitle);
        setSize(500, 270);
        setVisible(true);
        setFocusable(true);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        XYDataset dataset = createDataset();
        JFreeChart chart = createChart(dataset, chartTitle);
        ChartPanel chartPanel = new ChartPanel(chart);
        setContentPane(chartPanel);
        pack();
        updateChart();
    }

    private XYDataset createDataset() {
        used = new XYSeries("Used");
        total = new XYSeries("Total");
        free = new XYSeries("Free");
        XYSeriesCollection dataset = new XYSeriesCollection();
        dataset.addSeries(used);
        dataset.addSeries(total);
        dataset.addSeries(free);
        return dataset;
    }

    public double exec(String command) {
        StringBuffer buffer = new StringBuffer("");
        try {
            Process p = Runtime.getRuntime().exec(command);
            BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String line = null;
            while ((line = in.readLine()) != null) {
                buffer.append(line);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return Double.parseDouble(buffer.toString());
    }

    private double getRam(String arg) {
        return exec("./util " + arg);
    }

    private void updateChart() {
        int i = 0;
        while (true) {
            double used = getRam("used");
            double total = getRam("total");
            double free = getRam("free");
            this.used.add(i, used);
            this.total.add(i, total);
            this.free.add(i, free);
            try {
                Thread.sleep(1000);
            } catch (Exception e) {
            }
            ++i;
        }
    }

    private JFreeChart createChart(XYDataset dataset, String title) {
        JFreeChart chart = ChartFactory.createXYLineChart(title, "X", "Y", dataset, PlotOrientation.VERTICAL, true,
                true, false);
        XYPlot plot = chart.getXYPlot();
        XYSplineRenderer renderer = new XYSplineRenderer(); // Curve
        plot.setRenderer(renderer);
        return chart;
    }
}