[计算机软件及应用]java英文第八版十六章答案.doc

import javax.swing.*;import java.awt.*;import java.awt.event.*;public class Exercise16_2 extends JFrame implements ComponentListener public Exercise16_2() / Set the window title setTitle(Exercise16_2); / Register the frame as a listener for component events this.addComponentListener(this); /* Main method */ public static void main(String args) Exercise16_2 frame = new Exercise16_2(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(100, 80); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLocationRelativeTo(null); / Center the frame frame.setVisible(true); public void componentMoved(ComponentEvent e) System.out.println(Component moved); public void componentHidden(ComponentEvent e) System.out.println(Component hidden); public void componentResized(ComponentEvent e) System.out.println(Component resized); public void componentShown(ComponentEvent e) System.out.println(Component shown); import java.awt.*;import java.awt.event.*;import javax.swing.*;public class Exercise16_4 extends JFrame / Text fields for Number 1, Number 2, and Result private JTextField jtfNum1, jtfNum2, jtfResult; / Buttons Add, Subtract, Multiply and Divide private JButton jbtAdd, jbtSub, jbtMul, jbtDiv; / Main Method public static void main(String args) Exercise16_4 frame = new Exercise16_4(); frame.pack(); frame.setTitle(Exercise16_4); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLocationRelativeTo(null); / Center the frame frame.setVisible(true); / Default Constructor public Exercise16_4() / Panel p1 to hold text fields and labels JPanel p1 = new JPanel(); p1.setLayout(new FlowLayout(); p1.add(new JLabel(Number 1); p1.add(jtfNum1 = new JTextField(3); p1.add(new JLabel(Number 2); p1.add(jtfNum2 = new JTextField(3); p1.add(new JLabel(Result); p1.add(jtfResult = new JTextField(8); jtfResult.setEditable(false); jtfResult.setHorizontalAlignment(SwingConstants.RIGHT); / Panel p2 to hold buttons JPanel p2 = new JPanel(); p2.setLayout(new FlowLayout(); p2.add(jbtAdd = new JButton(Add); p2.add(jbtSub = new JButton(Subtract); p2.add(jbtMul = new JButton(Multiply); p2.add(jbtDiv = new JButton(Divide); / Set mnemonic keys jbtAdd.setMnemonic(A); jbtSub.setMnemonic(S); jbtMul.setMnemonic(M); jbtDiv.setMnemonic(D); / Add panels to the frame setLayout(new BorderLayout(); add(p1, BorderLayout.CENTER); add(p2, BorderLayout.SOUTH); / Register listeners jbtAdd.addActionListener(new Listener(); jbtSub.addActionListener(new Listener(); jbtMul.addActionListener(new Listener(); jbtDiv.addActionListener(new Listener(); class Listener implements ActionListener / Handle ActionEvent from buttons and menu items public void actionPerformed(ActionEvent e) String actionCommand = e.getActionCommand(); if (Add.equals(actionCommand) calculate(+); else if (Subtract.equals(actionCommand) calculate(-); else if (Multiply.equals(actionCommand) calculate(*); else if (Divide.equals(actionCommand) calculate(/); / Calculate and show the result in jtfResult private void calculate(char operator) / Obtain Number 1 and Number 2 double num1 = new Double(jtfNum1.getText().trim().doubleValue(); double num2 = new Double(jtfNum2.getText().trim().doubleValue(); double result = 0; / Perform selected operation switch (operator) case +: result = num1 + num2; break; case -: result = num1 - num2; break; case *: result = num1 * num2; break; case /: result = num1 / num2; / Set result in jtfResult jtfResult.setText(String.valueOf(result); import java.awt.*;import java.awt.event.*;import javax.swing.*;public class Exercise16_6 extends JFrame private DisplayPanel panel = new DisplayPanel(); public Exercise16_6() add(panel, BorderLayout.CENTER); panel.setFocusable(true); /* Main method */ public static void main(String args) JFrame frame = new Exercise16_6(); frame.setTitle(Exercise16_6); frame.setSize(300, 300); frame.setLocationRelativeTo(null); / Center the frame frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); class DisplayPanel extends MessagePanel private String m1 = Java is fun; private String m2 = Java is powerful; private boolean isM1; public DisplayPanel() setCentered(true); this.addMouseListener(new MouseAdapter() public void mouseClicked(MouseEvent e) if (isM1) setMessage(m1); else setMessage(m2); isM1 = !isM1; ); import javax.swing.*;import java.awt.*;import java.awt.event.*;public class Exercise16_8 extends JFrame public Exercise16_8() add(new DisplayCoordinatePanelONE(); /*Main method*/ public static void main(String args) / Create a frame Exercise16_8 frame = new Exercise16_8(); frame.setTitle(Exercise16_8); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(300, 300); frame.setLocationRelativeTo(null); / Center the frame frame.setVisible(true); /* Version 1: Display mouse position when the mouse is clicked */class DisplayCoordinatePanelONE extends JPanel / Point is a Java object for representing points in a plane. / p.x and p.y are the x and y coordinates. private Point p = new Point(0, 0); public DisplayCoordinatePanelONE() addMouseListener(new MouseAdapter() / When mouse is clicked, the mouse pointer location is / captured in the point p. public void mouseClicked(MouseEvent e) p.x = e.getX(); p.y = e.getY(); repaint(); ); / Draw a small solid square around the point public void paintComponent(Graphics g) super.paintComponent(g); g.drawString( + p.x + , + p.y + ), p.x, p.y); /* Version 2: Display mouse position when the mouse is pressed. The display disappears when the mouse is released. */class DisplayCoordinatePanelTWO extends JPanel / Point is a Java object for representing points in a plane. / p.x and p.y are the x and y coordinates. private Point p = new Point(0, 0); private boolean pressed = false; public DisplayCoordinatePanelTWO() addMouseListener(new MouseAdapter() public void mousePressed(MouseEvent e) p.x = e.getX(); p.y = e.getY(); pressed = true; repaint(); public void mouseReleased(MouseEvent e) pressed = false; repaint(); ); / Draw a small solid square around the point public void paintComponent(Graphics g) super.paintComponent(g); if (pressed) g.drawString( + p.x + , + p.y + ), p.x, p.y); import java.awt.*;import java.awt.event.*;import javax.swing.*;public class Exercise16_10 extends JFrame private DisplayPanel panel = new DisplayPanel(); public Exercise16_10() add(panel, BorderLayout.CENTER); panel.setFocusable(true); /* Main method */ public static void main(String args) JFrame frame = new Exercise16_10(); frame.setTitle(Exercise16_10); frame.setSize(300, 300); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLocationRelativeTo(null); / Center the frame frame.setVisible(true); class DisplayPanel extends MessagePanel private String message = ; private StringBuffer buffer = new StringBuffer(); public DisplayPanel() setCentered(true); this.addKeyListener(new Listener(); / Add listener class Listener extends KeyAdapter public void keyTyped(KeyEvent e) buffer.append(e.getKeyChar(); public void keyPressed(KeyEvent e) if (e.getKeyCode() = KeyEvent.VK_ENTER) message = buffer.toString().trim(); buffer.setLength(0); setMessage(message); import java.awt.*;import java.awt.event.*;import javax.swing.*;public class Exercise16_12 extends JFrame public Exercise16_12() add(new Fan(); / Main method public static void main(String args) / Create a frame Exercise16_12 frame = new Exercise16_12(); frame.setTitle(Exercise16_12: Running Fan); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); / Display the frame frame.setSize(200, 200); frame.setLocationRelativeTo(null); / Center the frame frame.setVisible(true); class Fan extends JPanel private int xCenter, yCenter;private int fanRadius, bladeLength;private int angle = 100;private int direction = 1;private int speed = 10;protected Timer timer = new Timer(speed, new TimerListener(); public Fan() timer.start();public void reverse() direction = -direction; public void setSpeed(int ms) speed = ms; timer.setDelay(speed); public void paintComponent(Graphics g) super.paintComponent(g); / Set clock radius, and center fanRadius = (int)(Math.min(getSize().width, getSize().height)*0.9*0.5); xCenter = (getSize().width)/2; yCenter = (getSize().height)/2; bladeLength = (int)(fanRadius*0.9); angle = (angle+direction)%360; / Draw circle g.setColor(Color.black); g.drawOval(xCenter - fanRadius,yCenter - fanRadius, 2*fanRadius, 2*fanRadius); / Draw four blades drawBlade(g, angle); drawBlade(g, angle+90); drawBlade(g, angle+180); drawBlade(g, angle+270);private void drawBlade(Graphics g, int angle) g.setColor(Color.red); g.fillArc(xCenter-bladeLength, yCenter-bladeLength, 2*bladeLength, 2*bladeLength, angle, 30); class TimerListener implements ActionListener public void actionPerformed(java.awt.event.ActionEvent actionEvent) repaint(); import javax.swing.*;import java.awt.*;import java.awt.event.*;import java.applet.*;import .*;public class Exercise16_14 extends JFrame public Exercise16_14() URL imageURL = this.getClass().getResource(image/us.gif); Image image = new ImageIcon(imageURL).getImage(); add(new FlagAnthemPanel(image); public static class FlagAnthemPanel extends JPanel private Image image; private Timer timer = new Timer(400, new Listener(); int x = 20; int y = 150; public FlagAnthemPanel(Image image) this.image = image; timer.start(); public void paintComponent(Graphics g) super.paintComponent(g); if (y 0) y -= 1; g.drawImage(image, x, y, 60, 40, this); class Listener implements ActionListener public void actionPerformed(ActionEvent e) repaint(); public static void main(String args) / Create a frame JFrame frame = new Exercise16_14(); frame.setTitle(Exercise16_14); / Display the frame frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(300, 200); frame.setLocationRelativeTo(null); / Center the frame frame.setVisible(true); import java.awt.*;import java.awt.event.*;import javax.swing.*;public class Exercise16_16 extends JFrame public Exercise16_16() add(new FlashLabel(Welcome to Java); / Main method public static void main(String args) / Create a frame JFrame frame = new Exercise16_16(); frame.setTitle(Exercise16_16); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); / Display the frame frame.setSize(200, 200); frame.setLocationRelativeTo(null); / Center the frame frame.setVisible(true); class FlashLabel extends JPanel private boolean show = true; private Timer timer = new Timer(200, new ActionListener() public void actionPerformed(ActionEvent e) repaint(); ); String label = Welcome to Java; public FlashLabel(String label) this.label = label; timer.start(); public void setLabel(String label) this.label = label; public void paintComponent(Graphics g) super.paintComponent(g); if (show) g.drawString(label, 20, 20); show = !show; public Dimension getPreferredSize() return new Dimension(200, 50); import java.awt.*;import java.awt.event.*;import javax.swing.*;public class Exercise16_18 extends JFrame public Exercise16_18() add(new MovingCircleByArrowKey(); /* Main method */ public static void main(String args) Exercise16_18 frame = new Exercise16_18(); frame.setTitle(Exercise16_18); frame.setSize(200, 100); frame.setLocationRelativeTo(null); / Center the frame frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); / Displaying a moving circleclass MovingCircleByArrowKey extends JPanel private int x = 20; private int y = 20; public static int RADIUS = 10; public MovingCircleByArrowKey() this.setFocusable(true); this.addKeyListener(new KeyAdapter() public void keyPressed(KeyEvent e) switch (e.getKeyCode() case KeyEvent.VK_DOWN: y += 10; break; case KeyEvent.VK_UP: y -= 10; break; case KeyEvent.VK_LEFT: x -= 10; break; case KeyEvent.VK_RIGHT: x += 10; break; default: ; repaint(); ); /* Paint message */ public void paintComponent(Graphics g) super.paintComponent(g); g.drawOval(x - RADIUS, y - RADIUS, 2 * RADIUS, 2 * RADIUS); import javax.swing.*;import java.awt.*;import java.awt.event.*;import javax.swing.border.*;public class Exercise16_20 extends JFrame private PaintPanel paintPanel = new PaintPanel(); public Exercise16_20() add(paintPanel); static class PaintPanel extends JPanel private MyRectangle2D rectangle = new MyRectangle2D(100, 60, 100, 40); private boolean isInside = false; private Point mousePoint = new Point(0, 0); public static int RADIUS = 50; public PaintPanel() this.addMouseMotionListener(new MouseAdapter() public void mouseMoved(MouseEvent e) if (rectangle.contains(e.getX(), e.getY() isInside = true; else isInside = false; mousePoint.x = e.getX(); mousePoint.y = e.getY(); repaint(); ); /* Paint message */ public void paintComponent(Graphics g) super.paintComponent(g); g.drawRect(int)(rectangle.getX() - (int)(rectangle.getWidth() / 2), (int)(rectangle.getY() - (int)(rectangle.getHeight() / 2), (int)(rectangle.getWidth(), (int)(rectangle.getHeight(); g.drawString(isInside ? Mouse point is in the rectangle : Mouse point is not in the rectangle, mousePoint.x, mousePoint.y); public static void main(String args) JFrame frame = new Exercise16_20(); frame.setTitle(Exercise16_20); frame.setSize(300, 300); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLocationRelativeTo(null); frame.setVisible(true); import javax.swing.*;import java.awt.*;import java.awt.event.*;public class Exercise16_22 extends JFrame final static int NUMBER_OF_SLOTS = 9; final static int NUMBER_OF_ROWS = NUMBER_OF_SLOTS - 2; private int shift = 0; private int slots = new intNUMBER_OF_SLOTS; private int numberOfBallsDropped = 0; private int moveCount = 0; private int position = 0; private BeanMachinePanel paintPanel = new BeanMachinePanel(); private Timer timer = new Timer(200, new ActionListener() public void actionPerformed(ActionEvent e) moveCount+; if (moveCount = NUMBER_OF_ROWS) if (Math.random() 0.5) paintPanel.moveRedBallLeft(); else paintPanel.moveRedBallRight(); position+; else slotsposition+; paintPanel.startRedBall(); shift = 0; moveCount = 0; position = 0; numberOfBallsDropped+; if (numberOfBallsDropped = 10) timer.stop(); paintPanel.hideRedBall(); ); public Exercise16_22() add(paintPanel); timer.start(); class BeanMachinePanel extends JPanel final static int HGAP = 20; final static int VGAP = 20; final static int RADIUS = 5; f