高手帮忙 救救我 在线等 指教我那里不对 然后帮我改下 谢谢
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.util.*;
import javax.swing.*;
/**
Shouws an animated bouncing ball.
*/
public class BounceThread
{
public static void main(String[] args)
{
JFrame frame = new BounceFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
/**
A ball that moves and bounces off the edges of a rectangle
*/
class BallRunable implements Runnable
{
/**
Constructs the runnable.
@aBall the ball to bounce
@aPanel the component in which the ball bounces
*/
public BallRunnable(Ball aBall, Component aComponent)
{
ball = aBall;
component = aComponent;
}
public void run()
{
try
{
for (int i=1;i <= STEPS;i++ )
{
ball.move(component.getBounds());
component.repaint();
Thread.sleep(DELAY);
}
}
catch (InterruptedException e)
{
}
}
private Ball ball;
private Component component;
public static final int STEPS = 1000;
public static final int DELAY = 5;
}
class Ball
{
/**
moves the ball to the next position, reversing direction
if it hits one of the edges
*/
public void move(Rectangle2D bounds)
{
x += dx;
y += dy;
if (x < bounds.getMinX())
{
x = bounds.getMinX();
dx = -dx;
}
if (x + XSIZE >= bounds.getMaxX())
{
x = bounds.getMaxX() - XSIZE;
dx = -dx;
}
if (y < bounds.getMinY())
{
y = bounds.getMinY();
dy = -dy;
}
if (y + YSIZE >= bounds.getMaxY())
{
y = bounds.getMaxY() - YSIZE;
dy = -dy;
}
}
/**
Gets the shape of the ball at its current position.
*/
public Ellipse2D getShape()
{
return new Ellipse2D.Double(x,y,XSIZE,YSIZE);
}
private static final int XSIZE = 15;
private static final int YSIZE = 15;
private double x = 0;
private double y = 0;
private double dx = 1;
private double dy = 1;
}
/**
The panel that draws the balls.
*/
class BallPanel extends JPanel
{
/**
add a ball to the panel.
@param b the ball to add
*/
public void add(Ball b)
{
balls.add(b);
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
for (Ball b : balls )
{
g2.fill(b.getShape());
}
}
private ArrayList<Ball> balls = new ArrayList<Ball>();
}
/**
The frame with panel and buttons.
*/
class BounceFrame extends JFrame
{
/**
Constructs the frame with the panel for showing the
bouncing ball and Start and Close buttons
*/
public BounceFrame()
{
setSize(DEFAULT_WIDTH,DEFAULT_HEIGHT);
setTitle("Bounce");
panel = new BallPanel();
add(panel,BorderLayout.CENTER);
JPanel buttonPanel = new JPanel();
addButton(buttonPanel,"Start",
new ActionListener()
{
public void actionPerformed(ActionEvent event)
{
addBall();
}
});
addButton(buttonPanel,"Close",
new ActionListener()
{
public void actionPerformed(ActionEvent event){
System.exit(0);
}
});
add(buttonPanel,BorderLayout.SOUTH);
}
/**
Adss a button to a container.
@param c the container
@param title the button title
@parme listener the action listener for the button
*/
public void addButton(Container c,String title,ActionListener listener)
{
JButton button = new JButton(title);
c.add(button);
button.addActionListener(listener);
}
/**
Adds a bouncing ball to the canvas and starts a thread
to make it bounce
*/
public void addBall()
{
Ball b = new Ball();
panel.add(b);
Runnable r = new BallRunnable(b,panel);
Thread t = new Thread(r);
t.start();
}
private BallPanel panel;
public static final int DEFAULT_WIDTH = 450;
public static final int DEFAULT_HEIGHT = 350;
public static final int STEPS = 1000;
public static final int DELAY = 3;
}
就是说要
BounceThread.java:30: 方法声明无效；需要返回类型
public BallRunnable(Ball aBall, Component aComponent)
我在线等
[解决办法]
import java.awt.*;import java.awt.event.*;import java.awt.geom.*;import java.util.*;import javax.swing.*;/** Shouws an animated bouncing ball. */ public class BounceThread {public static void main(String[] args){JFrame frame = new BounceFrame();frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);frame.setVisible(true);}}/** A ball that moves and bounces off the edges of a rectangle*/class BallRunnable implements Runnable{/** Constructs the runnable. @aBall the ball to bounce @aPanel the component in which the ball bounces */ public BallRunnable(Ball aBall, Component aComponent){ ball = aBall; component = aComponent; } public void run(){ try {for (int i=1;i <= STEPS;i++ ){ball.move(component.getBounds());component.repaint();Thread.sleep(DELAY);} } catch (InterruptedException e) { } } private Ball ball; private Component component; public static final int STEPS = 1000; public static final int DELAY = 5;}class Ball{/** moves the ball to the next position, reversing directionif it hits one of the edges*/public void move(Rectangle2D bounds){x += dx;y += dy;if (x < bounds.getMinX()){x = bounds.getMinX();dx = -dx;}if (x + XSIZE > = bounds.getMaxX()){x = bounds.getMaxX() - XSIZE;dx = -dx;}if (y < bounds.getMinY()){y = bounds.getMinY();dy = -dy;}if (y + YSIZE > = bounds.getMaxY()){y = bounds.getMaxY() - YSIZE;dy = -dy;}}/**Gets the shape of the ball at its current position.*/public Ellipse2D getShape(){ return new Ellipse2D.Double(x,y,XSIZE,YSIZE);}private static final int XSIZE = 15;private static final int YSIZE = 15;private double x = 0;private double y = 0;private double dx = 1;private double dy = 1;}/** The panel that draws the balls. */class BallPanel extends JPanel{/** add a ball to the panel. @param b the ball to add*/ public void add(Ball b){ balls.add(b); }public void paintComponent(Graphics g){ super.paintComponent(g); Graphics2D g2 = (Graphics2D) g; for (Ball b : balls ) { g2.fill(b.getShape()); }}private ArrayList <Ball> balls = new ArrayList <Ball> ();}/** The frame with panel and buttons. */class BounceFrame extends JFrame{/**Constructs the frame with the panel for showing thebouncing ball and Start and Close buttons*/ public BounceFrame(){ setSize(DEFAULT_WIDTH,DEFAULT_HEIGHT); setTitle("Bounce"); panel = new BallPanel(); add(panel,BorderLayout.CENTER); JPanel buttonPanel = new JPanel(); addButton(buttonPanel,"Start", new ActionListener(){ public void actionPerformed(ActionEvent event){ addBall(); } }); addButton(buttonPanel,"Close", new ActionListener(){ public void actionPerformed(ActionEvent event){ System.exit(0); } }); add(buttonPanel,BorderLayout.SOUTH); }/** Adss a button to a container.@param c the container@param title the button title@parme listener the action listener for the button*/public void addButton(Container c,String title,ActionListener listener){ JButton button = new JButton(title); c.add(button); button.addActionListener(listener);}/**Adds a bouncing ball to the canvas and starts a threadto make it bounce*/public void addBall(){ Ball b = new Ball(); panel.add(b); Runnable r = new BallRunnable(b,panel); Thread t = new Thread(r); t.start();}private BallPanel panel;public static final int DEFAULT_WIDTH = 450;public static final int DEFAULT_HEIGHT = 350;public static final int STEPS = 1000;public static final int DELAY = 3;}
[解决办法]
牛人.
[解决办法]
public BallRunnable(Ball aBall, Component aComponent)
[解决办法]
第一处:
public BallRunnable(Ball aBall, Component aComponent) 构造方法名BallRuunnable 与类名 BallRunable不一致
[解决办法]
core java 高级特性
下册第一章 multiple thread
源代码有的是