systemmonitor.java

著名的开源仿真软件yale

/*
 *  YALE - Yet Another Learning Environment
 *  Copyright (C) 2002, 2003
 *      Simon Fischer, Ralf Klinkenberg, Ingo Mierswa, 
 *          Katharina Morik, Oliver Ritthoff
 *      Artificial Intelligence Unit
 *      Computer Science Department
 *      University of Dortmund
 *      44221 Dortmund,  Germany
 *  email: [e-mail]
 *  web:   http://yale.cs.uni-dortmund.de/
 *
 *  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 2 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, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 *  USA.
 */
package edu.udo.cs.yale.gui;

import javax.swing.JPanel;
import java.awt.Graphics;
import java.awt.Component;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.geom.GeneralPath;

public class SystemMonitor extends JPanel {

    private static final Color MEMORY_COLOR = new Color(0,200,0); //,128);
    private static final Color TEXT_COLOR   = new Color(0,220,0);
    private static final Color GRID_COLOR   = Color.gray;
    private static final Color BACKGROUND   = new Color(0,60,0);

    private static final String[] MEMORY_UNITS = { "b", "kb", "Mb", "Gb", "Tb" };

    private static final int NUMBER_OF_MEASUREMENTS = 20;
    private static final int GRID_X = 10;
    private static final int GRID_Y = 10;
    private static final int MARGIN = 10;

    private long delay = 1000;
    private long[] memory = new long[NUMBER_OF_MEASUREMENTS];
    private int currentMeasurement = 0;

    public SystemMonitor() {
	setBackground(BACKGROUND);
	new Thread() {
		{
		    setDaemon(true);
		}
		public void run() {
		    setPriority(MIN_PRIORITY);
		    while (true) {
			SystemMonitor.this.memory[SystemMonitor.this.currentMeasurement] = 
			     Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory();
			SystemMonitor.this.currentMeasurement = 
			    (SystemMonitor.this.currentMeasurement+1) %
			    SystemMonitor.this.memory.length;
			SystemMonitor.this.repaint();
			try {
			    sleep(delay);
			} catch (InterruptedException e) {
			}
		    }
		}
	    }.start();
    }

    public void paintComponent(Graphics g) {
	super.paintComponent(g);

	GeneralPath path = new GeneralPath();

	Dimension d = getSize();
	int monitorWidth  = (int)d.getWidth()  - 2*MARGIN;
	int monitorHeight = (int)d.getHeight() - 2*MARGIN;

	long total = Runtime.getRuntime().totalMemory();

	path.moveTo(MARGIN, MARGIN+monitorHeight);
	for (int i = 0; i < memory.length; i++) {
	    int index = (currentMeasurement + i)  % memory.length;
	    path.lineTo(MARGIN + i * monitorWidth / (memory.length-1),
			MARGIN + monitorHeight - monitorHeight*memory[index]/total);
	}
	path.lineTo(MARGIN + monitorWidth, 
		    MARGIN + monitorHeight);
	path.closePath();

	Graphics2D g2d = (Graphics2D)g;

	g2d.setColor(GRID_COLOR);
	for (int x = 0; x < GRID_X+1; x++) {
	    g2d.drawLine(MARGIN + x * monitorWidth / GRID_X, MARGIN,
			 MARGIN + x * monitorWidth / GRID_X, MARGIN + monitorHeight);
	}
	for (int y = 0; y < GRID_Y+1; y++) {
	    g2d.drawLine(MARGIN,                MARGIN + y * monitorHeight / GRID_Y, 
			 MARGIN + monitorWidth, MARGIN + y * monitorHeight / GRID_Y);
	}

	g2d.setColor(MEMORY_COLOR);
	g2d.fill(path);
	g2d.setColor(Color.green);
	g2d.draw(path);

	g2d.setColor(TEXT_COLOR);
	Font font = new Font("Courier", Font.PLAIN, 12);
	g2d.setFont(font);
	g2d.drawString(" Total: " + humanReadable(total), MARGIN, MARGIN+3*font.getSize()/2);
	g2d.drawString(" Max:   " + humanReadable(Runtime.getRuntime().maxMemory()), MARGIN, MARGIN + 5*font.getSize()/2);
    }

    public String humanReadable(long bytes) {
	long result = bytes;
	long rest = 0;
	int unit = 0;
	while (result > 1024) {
	    rest   = result % 1024;
	    result /= 1024;
	    unit++;
	    if (unit >= MEMORY_UNITS.length-1) break;
	}
	if ((result < 10) && (unit > 0)) {
	    return result+"."+(10*rest/1024)+" "+MEMORY_UNITS[unit];
	} else {
	    return result+" "+MEMORY_UNITS[unit];
	}
    }
}