memorymonitor.java

一个小公司要求给写的很简单的任务管理系统。

/*
 * @(#)MemoryMonitor.java	1.3 05/11/17
 * 
 * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * -Redistribution of source code must retain the above copyright notice, this
 *  list of conditions and the following disclaimer.
 * 
 * -Redistribution in binary form must reproduce the above copyright notice, 
 *  this list of conditions and the following disclaimer in the documentation
 *  and/or other materials provided with the distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may 
 * be used to endorse or promote products derived from this software without 
 * specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL 
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST 
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, 
 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY 
 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, 
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 * 
 * You acknowledge that this software is not designed, licensed or intended
 * for use in the design, construction, operation or maintenance of any
 * nuclear facility.
 */

/*
 * @(#)MemoryMonitor.java	1.3 05/11/17
 */

import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;
import java.util.Date;
import javax.swing.*;
import javax.swing.border.EtchedBorder;
import javax.swing.border.TitledBorder;
import java.lang.management.*;
import java.util.*;


/**
 * Demo code which plots the memory usage by all memory pools.
 * The memory usage is sampled at some time interval using 
 * java.lang.management API. This demo code is modified based
 * java2d MemoryMonitor demo. 
 */
public class MemoryMonitor extends JPanel {

    static JCheckBox dateStampCB = new JCheckBox("Output Date Stamp");
    public Surface surf;
    JPanel controls;
    boolean doControls;
    JTextField tf;
    // Get memory pools.
    static java.util.List<MemoryPoolMXBean> mpools = 
        ManagementFactory.getMemoryPoolMXBeans();
    // Total number of memory pools.
    static int numPools = mpools.size();

    public MemoryMonitor() {
        setLayout(new BorderLayout());
        setBorder(new TitledBorder(new EtchedBorder(), "Memory Monitor"));
        add(surf = new Surface());
        controls = new JPanel();
        controls.setPreferredSize(new Dimension(135,80));
        Font font = new Font("serif", Font.PLAIN, 10);
        JLabel label = new JLabel("Sample Rate");
        label.setFont(font);
        label.setForeground(Color.red);
        controls.add(label);
        tf = new JTextField("1000");
        tf.setPreferredSize(new Dimension(45,20));
        controls.add(tf);
        controls.add(label = new JLabel("ms"));
        label.setFont(font);
        label.setForeground(Color.red);
        controls.add(dateStampCB);
        dateStampCB.setFont(font);
        addMouseListener(new MouseAdapter() {
            public void mouseClicked(MouseEvent e) {
               removeAll();
               if ((doControls = !doControls)) {
                   surf.stop();
                   add(controls);
               } else {
                   try { 
                       surf.sleepAmount = Long.parseLong(tf.getText().trim());
                   } catch (Exception ex) {}
                   surf.start();
                   add(surf);
               }
               validate();
               repaint();
            }
        });
    }


    public class Surface extends JPanel implements Runnable {

        public Thread thread;
        public long sleepAmount = 1000;
	public int  usageHistCount = 20000;
        private int w, h;
        private BufferedImage bimg;
        private Graphics2D big;
        private Font font = new Font("Times New Roman", Font.PLAIN, 11);
        private int columnInc;
        private float usedMem[][];
        private int ptNum[];
        private int ascent, descent;
        private Rectangle graphOutlineRect = new Rectangle();
        private Rectangle2D mfRect = new Rectangle2D.Float();
        private Rectangle2D muRect = new Rectangle2D.Float();
        private Line2D graphLine = new Line2D.Float();
        private Color graphColor = new Color(46, 139, 87);
        private Color mfColor = new Color(0, 100, 0);
        private String usedStr;
      

        public Surface() {
            setBackground(Color.black);
            addMouseListener(new MouseAdapter() {
                public void mouseClicked(MouseEvent e) {
                    if (thread == null) start(); else stop();
                }
            });
	    int i = 0;
	    usedMem = new float[numPools][];
	    ptNum = new int[numPools];
        }

        public Dimension getMinimumSize() {
            return getPreferredSize();
        }

        public Dimension getMaximumSize() {
            return getPreferredSize();
        }

        public Dimension getPreferredSize() {
            return new Dimension(135,80);
        }

            
        public void paint(Graphics g) {

            if (big == null) {
                return;
            }

            big.setBackground(getBackground());
            big.clearRect(0,0,w,h);


	    h = h / ((numPools + numPools%2) / 2); 
	    w = w / 2;

	    int k=0; // index of memory pool.
	    for (int i=0; i < 2;i++) {
	       for (int j=0; j < (numPools + numPools%2)/ 2; j++) {
	         plotMemoryUsage(w*i,h*j,w,h,k);
		 if (++k >= numPools) {
		    i = 3;
		    j = (numPools + numPools%2)/ 2;
		    break;
		 }
	       }
	    }
            g.drawImage(bimg, 0, 0, this);
        }

	public void plotMemoryUsage(int x1, int y1, int x2, int y2, int npool) {

	    MemoryPoolMXBean mp = mpools.get(npool); 
	    float usedMemory =  mp.getUsage().getUsed();
            float totalMemory =  mp.getUsage().getMax();

            // .. Draw allocated and used strings ..
            big.setColor(Color.green);

	    // Print Max memory allocated for this memory pool.
            big.drawString(String.valueOf((int)totalMemory/1024) + "K Max ", x1+4.0f, (float) y1 + ascent+0.5f);
            big.setColor(Color.yellow);

	    // Print the memory pool name.
            big.drawString(mp.getName(),  x1+x2/2, (float) y1 + ascent+0.5f);

	    // Print the memory used by this memory pool.
            usedStr = String.valueOf((int)usedMemory/1024) 
                + "K used";
            big.setColor(Color.green);
            big.drawString(usedStr, x1+4, y1+y2-descent);

            // Calculate remaining size
            float ssH = ascent + descent;
            float remainingHeight = (float) (y2 - (ssH*2) - 0.5f);
            float blockHeight = remainingHeight/10;
            float blockWidth = 20.0f;
            float remainingWidth = (float) (x2 - blockWidth - 10);

            // .. Memory Free ..
            big.setColor(mfColor);
            int MemUsage = (int) (((totalMemory - usedMemory) / totalMemory) * 10);
            int i = 0;
            for ( ; i < MemUsage ; i++) { 
                mfRect.setRect(x1+5,(float) y1+ssH+i*blockHeight,
                                blockWidth,(float) blockHeight-1);
                big.fill(mfRect);
            }

            // .. Memory Used ..
            big.setColor(Color.green);
            for ( ; i < 10; i++)  {
                muRect.setRect(x1+5,(float) y1 + ssH+i*blockHeight,
                                blockWidth,(float) blockHeight-1);
                big.fill(muRect);
            }

            // .. Draw History Graph ..
	    if (remainingWidth <= 30) remainingWidth = (float)30;
	    if (remainingHeight <= ssH) remainingHeight = (float)ssH;
            big.setColor(graphColor);