package java2d;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;/** * Tracks Memory allocated & used, displayed in graph form. */public class MemoryMonitor extends JPanel {    static JCheckBox dateStampCB = new JCheckBox("Output Date Stamp");    public Surface surf;    JPanel controls;    boolean doControls;    JTextField tf;    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.black);        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.black);        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;        private int w, h;        private BufferedImage bimg;        private Graphics2D big;        private Font font = new Font("Times New Roman", Font.PLAIN, 11);        private Runtime r = Runtime.getRuntime();        private int columnInc;        private int pts[];        private int ptNum;        private int ascent, descent;        private float freeMemory, totalMemory;        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();                }            });        }        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);            float freeMemory = (float) r.freeMemory();            float totalMemory = (float) r.totalMemory();            // .. Draw allocated and used strings ..            big.setColor(Color.green);            big.drawString(String.valueOf((int) totalMemory/1024) + "K allocated",  4.0f, (float) ascent+0.5f);            usedStr = String.valueOf(((int) (totalMemory - freeMemory))/1024)                 + "K used";            big.drawString(usedStr, 4, h-descent);            // Calculate remaining size            float ssH = ascent + descent;            float remainingHeight = (float) (h - (ssH*2) - 0.5f);            float blockHeight = remainingHeight/10;            float blockWidth = 20.0f;            float remainingWidth = (float) (w - blockWidth - 10);            // .. Memory Free ..            big.setColor(mfColor);            int MemUsage = (int) ((freeMemory / totalMemory) * 10);            int i = 0;            for ( ; i < MemUsage ; i++) {                 mfRect.setRect(5,(float) ssH+i*blockHeight,                                blockWidth,(float) blockHeight-1);                big.fill(mfRect);            }            // .. Memory Used ..            big.setColor(Color.green);            for ( ; i < 10; i++)  {                muRect.setRect(5,(float) ssH+i*blockHeight,                                blockWidth,(float) blockHeight-1);                big.fill(muRect);            }            // .. Draw History Graph ..            big.setColor(graphColor);            int graphX = 30;            int graphY = (int) ssH;            int graphW = w - graphX - 5;            int graphH = (int) remainingHeight;            graphOutlineRect.setRect(graphX, graphY, graphW, graphH);            big.draw(graphOutlineRect);            int graphRow = graphH/10;            // .. Draw row ..            for (int j = graphY; j <= graphH+graphY; j += graphRow) {                graphLine.setLine(graphX,j,graphX+graphW,j);                big.draw(graphLine);            }                    // .. Draw animated column movement ..            int graphColumn = graphW/15;            if (columnInc == 0) {                columnInc = graphColumn;            }            for (int j = graphX+columnInc; j < graphW+graphX; j+=graphColumn) {                graphLine.setLine(j,graphY,j,graphY+graphH);                big.draw(graphLine);            }            --columnInc;            if (pts == null) {                pts = new int[graphW];                ptNum = 0;            } else if (pts.length != graphW) {                int tmp[] = null;                if (ptNum < graphW) {                         tmp = new int[ptNum];                    System.arraycopy(pts, 0, tmp, 0, tmp.length);                } else {                            tmp = new int[graphW];                    System.arraycopy(pts, pts.length-tmp.length, tmp, 0, tmp.length);                    ptNum = tmp.length - 2;                }                pts = new int[graphW];                System.arraycopy(tmp, 0, pts, 0, tmp.length);            } else {                big.setColor(Color.yellow);                pts[ptNum] = (int)(graphY+graphH*(freeMemory/totalMemory));                for (int j=graphX+graphW-ptNum, k=0;k < ptNum; k++, j++) {                    if (k != 0) {                        if (pts[k] != pts[k-1]) {                            big.drawLine(j-1, pts[k-1], j, pts[k]);                        } else {                            big.fillRect(j, pts[k], 1, 1);                        }                    }                }                if (ptNum+2 == pts.length) {                    // throw out oldest point                    for (int j = 1;j < ptNum; j++) {                        pts[j-1] = pts[j];                    }                    --ptNum;                } else {                    ptNum++;                }            }            g.drawImage(bimg, 0, 0, this);        }        public void start() {            thread = new Thread(this);            thread.setPriority(Thread.MIN_PRIORITY);            thread.setName("MemoryMonitor");            thread.start();        }        public synchronized void stop() {            thread = null;            notify();        }        public void run() {            Thread me = Thread.currentThread();            while (thread == me && !isShowing() || getSize().width == 0) {                try {                    thread.sleep(500);                } catch (InterruptedException e) { return; }            }                while (thread == me && isShowing()) {                Dimension d = getSize();                if (d.width != w || d.height != h) {                    w = d.width;                    h = d.height;                    bimg = (BufferedImage) createImage(w, h);                    big = bimg.createGraphics();                    big.setFont(font);                    FontMetrics fm = big.getFontMetrics(font);                    ascent = (int) fm.getAscent();                    descent = (int) fm.getDescent();                }                repaint();                try {                    thread.sleep(sleepAmount);                } catch (InterruptedException e) { break; }                if (MemoryMonitor.dateStampCB.isSelected()) {                     System.out.println(new Date().toString() + " " + usedStr);                }            }            thread = null;        }    }    public static void main(String s[]) {        final MemoryMonitor demo = new MemoryMonitor();        WindowListener l = new WindowAdapter() {            public void windowClosing(WindowEvent e) {System.exit(0);}            public void windowDeiconified(WindowEvent e) { demo.surf.start(); }            public void windowIconified(WindowEvent e) { demo.surf.stop(); }        };        JFrame f = new JFrame("Java2D Demo - MemoryMonitor");        f.addWindowListener(l);        f.getContentPane().add("Center", demo);        f.pack();        f.setSize(new Dimension(200,200));        f.setVisible(true);        demo.surf.start();    }}