javaapplet.java

有关java的源程序,为讲授java程序设计课程使用

//******************************************************************************
// JavaApplet.java:	Applet
//
//******************************************************************************
import java.applet.*;
import java.awt.*;
import java.net.*;

//==============================================================================
// Main Class for applet JavaApplet
//
//==============================================================================
public class JavaApplet extends Applet implements Runnable
{
	// THREAD SUPPORT:
	//		m_JavaApplet	is the Thread object for the applet
	//--------------------------------------------------------------------------
	private Thread	 m_JavaApplet = null;

	// ANIMATION SUPPORT:
	//		m_Graphics		used for storing the applet's Graphics context
	//		m_Images[]		the array of Image objects for the animation
	//		m_nCurrImage	the index of the next image to be displayed
	//		m_ImgWidth		width of each image
	//		m_ImgHeight		height of each image
	//		m_fAllLoaded	indicates whether all images have been loaded
	//		NUM_IMAGES 		number of images used in the animation
	//--------------------------------------------------------------------------
	private Graphics m_Graphics;
	private Image	 m_Images[];
	private int 	 m_nCurrImage;
	private int 	 m_nImgWidth  = 0;
	private int 	 m_nImgHeight = 0;
	private boolean  m_fAllLoaded = false;
	private final int NUM_IMAGES = 8;

	private TextField receiveEdit;
    private PlaySound playAudio;
	private Image backImage,ramImage;
	private boolean imageError=false;
	private boolean imageLoaded=false;

	// JavaApplet Class Constructor
	//--------------------------------------------------------------------------
	public JavaApplet()
	{
		// TODO: Add constructor code here
	}

	// APPLET INFO SUPPORT:
	//		The getAppletInfo() method returns a string describing the applet's
	// author, copyright date, or miscellaneous information.
    //--------------------------------------------------------------------------
	public String getAppletInfo()
	{
		return "Name: JavaApplet\r\n" +
		       "Author: wang\r\n" +
		       "Created with Microsoft Visual J++ Version 1.1";
	}


	// The init() method is called by the AWT when an applet is first loaded or
	// reloaded.  Override this method to perform whatever initialization your
	// applet needs, such as initializing data structures, loading images or
	// fonts, creating frame windows, setting the layout manager, or adding UI
	// components.
    //--------------------------------------------------------------------------
	public void init()
	{
        // If you use a ResourceWizard-generated "control creator" class to
        // arrange controls in your applet, you may want to call its
        // CreateControls() method from within this method. Remove the following
        // call to resize() before adding the call to CreateControls();
        // CreateControls() does its own resizing.
        //----------------------------------------------------------------------
    	//resize(100, 100);	//320,240

		// TODO: Place additional initialization code here
				setBackground(Color.yellow);
				setLayout(new BorderLayout());
				receiveEdit=new TextField(40);
				add("South",receiveEdit);
// load back ground image
			    backImage=
					getImage(getDocumentBase(),"images1/img01.gif");
// load Audio Sound file				
				playAudio=
					new PlaySound(this,getCodeBase(),"audio\\ah.au");
				playAudio.start();
	}

	// Place additional applet clean up code here.  destroy() is called when
	// when you applet is terminating and being unloaded.
	//-------------------------------------------------------------------------
	public void destroy()
	{
		// TODO: Place applet cleanup code here
	}

    // ANIMATION SUPPORT:
    //		Draws the next image, if all images are currently loaded
    //--------------------------------------------------------------------------
	private void displayImage(Graphics g)
	{
		if (!m_fAllLoaded)
			return;

		// Draw Image in center of applet
		//----------------------------------------------------------------------
		g.drawString("我可以接收JAVA Applet A的信息",10,20);
		g.clipRect((size().width - m_nImgWidth)/ 2,(size().height - m_nImgHeight)/ 2, 
				   m_nImgWidth,m_nImgHeight);
		
		g.setColor(getBackground());
		g.fillRect((size().width - m_nImgWidth)/ 2,(size().height - m_nImgHeight)/ 2, 
				   m_nImgWidth,m_nImgHeight);
		g.setColor(getForeground());
		g.drawImage(m_Images[m_nCurrImage],
				   (size().width - m_nImgWidth)   / 2,
				   (size().height - m_nImgHeight) / 2, null);
    }
		
	public boolean imageUpdate(Image image,int infoflags,int x,int y,int w,int h)
	{
		if((infoflags&ERROR)!=0)	// load image is error !
		{
			imageError=true;
			return true;
		}
		
		repaint();
		return ((infoflags&(ERROR|ALLBITS))!=0);
	}
	
	public void update(Graphics g)
	{
		paint(g);
	}

	// JavaApplet Paint Handler
	//--------------------------------------------------------------------------
	public void paint(Graphics g)
	{
	
		// ANIMATION SUPPORT:
	    // The following code displays a status message until all the
		// images are loaded. Then it calls displayImage to display the current
		// image.
		//----------------------------------------------------------------------
		if (m_fAllLoaded)
		{
			//Rectangle r = g.getClipRect();
			//g.clearRect(r.x, r.y, r.width, r.height);
			displayImage(g);
		}
		else
		    g.drawString("Loading Applet B images...", 10, 20);
	// TODO: Place additional applet Paint code here
	    Dimension rectSize=size();
		g.setColor(Color.red);
		g.draw3DRect(0,0,rectSize.width-1,rectSize.height-1,true);
		g.draw3DRect(3,3,rectSize.width-7,rectSize.height-7,false);
		g.setColor(getForeground());
	}

	//		The start() method is called when the page containing the applet
	// first appears on the screen. The AppletWizard's initial implementation
	// of this method starts execution of the applet's thread.
	//--------------------------------------------------------------------------
	public void start()
	{
		if (m_JavaApplet == null)
		{
			m_JavaApplet = new Thread(this);
			m_JavaApplet.start();
		}
		// TODO: Place additional applet start code here
		playAudio.startPlay();
	}
	
	//		The stop() method is called when the page containing the applet is
	// no longer on the screen. The AppletWizard's initial implementation of
	// this method stops execution of the applet's thread.
	//--------------------------------------------------------------------------
	public void stop()
	{
		if (m_JavaApplet != null)
		{
			m_JavaApplet.stop();
			m_JavaApplet = null;
		}

		// TODO: Place additional applet stop code here
		playAudio.stopPlay();
	}

	// THREAD SUPPORT
	//		The run() method is called when the applet's thread is started. If
	// your applet performs any ongoing activities without waiting for user
	// input, the code for implementing that behavior typically goes here. For
	// example, for an applet that performs animation, the run() method controls
	// the display of images.
	//--------------------------------------------------------------------------
	public void run()
	{
		m_nCurrImage = 0;
		
		// If re-entering the page, then the images have already been loaded.
		// m_fAllLoaded == TRUE.
		//----------------------------------------------------------------------
        if (!m_fAllLoaded)
		{
    		repaint();
    		m_Graphics = getGraphics();
    		m_Images   = new Image[NUM_IMAGES];

    		// Load in all the images
    		//------------------------------------------------------------------
    		MediaTracker tracker = new MediaTracker(this);
    		String strImage;

    		// For each image in the animation, this method first constructs a
    		// string containing the path to the image file; then it begins
    		// loading the image into the m_Images array.  Note that the call to
    		// getImage will return before the image is completely loaded.
    		//------------------------------------------------------------------
    		for (int i = 1; i <= NUM_IMAGES; i++)
    		{
    			// Build path to next image
    			//--------------------------------------------------------------
    			strImage = "images1/img" + ((i < 10) ? "0" : "") + i + ".gif";
			    m_Images[i-1] = getImage(getDocumentBase(), strImage);

                tracker.addImage(m_Images[i-1], 0);
    		}

    		// Wait until all images are fully loaded
    		//------------------------------------------------------------------
			try
			{
				tracker.waitForAll();
				m_fAllLoaded = !tracker.isErrorAny();
			}
			catch (InterruptedException e)
			{
				// TODO: Place exception-handling code here in case an
				//       InterruptedException is thrown by Thread.sleep(),
				//		 meaning that another thread has interrupted this one
			}
			
			if (!m_fAllLoaded)
			{
			    stop();
			    m_Graphics.drawString("Error loading images!", 10, 40);
			    return;
			}
			

			// Assuming all images are same width and height.
			//--------------------------------------------------------------
		    m_nImgWidth  = m_Images[6].getWidth(this);
		    m_nImgHeight = m_Images[6].getHeight(this);
        }		
		repaint();

		while (true)
		{
			try
			{
				// Draw next image in animation
				//--------------------------------------------------------------
				displayImage(m_Graphics);
				m_nCurrImage++;
				if (m_nCurrImage == NUM_IMAGES)
					m_nCurrImage = 0;
// TODO:  Add additional thread-specific code here
				Thread.sleep(50);
					
			}
			catch (InterruptedException e)
			{
				// TODO: Place exception-handling code here in case an
				//       InterruptedException is thrown by Thread.sleep(),
				//		 meaning that another thread has interrupted this one
				stop();
			}
		}
	}

	// MOUSE SUPPORT:
	//		The mouseDown() method is called if the mouse button is pressed
	// while the mouse cursor is over the applet's portion of the screen.
	//--------------------------------------------------------------------------
	public boolean mouseDown(Event evt, int x, int y)
	{
		// TODO: Place applet mouseDown code here
		return true;
	}

	// MOUSE SUPPORT:
	//		The mouseUp() method is called if the mouse button is released
	// while the mouse cursor is over the applet's portion of the screen.
	//--------------------------------------------------------------------------
	public boolean mouseUp(Event evt, int x, int y)
	{
		// TODO: Place applet mouseUp code here
		return true;
	}

	// MOUSE SUPPORT:
	//		The mouseDrag() method is called if the mouse cursor moves over the
	// applet's portion of the screen while the mouse button is being held down.
	//--------------------------------------------------------------------------
	public boolean mouseDrag(Event evt, int x, int y)
	{
		// TODO: Place applet mouseDrag code here
		return true;
	}

	// MOUSE SUPPORT:
	//		The mouseMove() method is called if the mouse cursor moves over the
	// applet's portion of the screen and the mouse button isn't being held down.
	//--------------------------------------------------------------------------
	public boolean mouseMove(Event evt, int x, int y)
	{
		// TODO: Place applet mouseMove code here
		return true;
	}

	// MOUSE SUPPORT:
	//		The mouseEnter() method is called if the mouse cursor enters the
	// applet's portion of the screen.
	//--------------------------------------------------------------------------
	public boolean mouseEnter(Event evt, int x, int y)
	{
		// TODO: Place applet mouseEnter code here
		return true;
	}

	// MOUSE SUPPORT:
	//		The mouseExit() method is called if the mouse cursor leaves the
	// applet's portion of the screen.
 	//--------------------------------------------------------------------------
	public boolean mouseExit(Event evt, int x, int y)
	{
		// TODO: Place applet mouseExit code here
		return true;
	}


	// TODO: Place additional applet code here
	public void processRequestFrom(String senderString)
	{
		receiveEdit.setText("OK Receive----"+senderString);
//Let Explore to Show HTML Document in The Applet Window
		getAppletContext().showDocument(getDocumentBase());
//Display Host Name String
		if(getCodeBase().getHost()==null)
			showStatus("Host is Null String");
		showStatus(getCodeBase().getHost());
	}

}

//--------Audio Class to Play Sound(must have Sound Hardware Support)
class PlaySound extends Thread
{
	Applet applet;
	URL baseURL;
	String audioFileName;
	AudioClip audioClip=null;

	public PlaySound(Applet applet,URL baseURL,String audioFileName)
	{
		this.applet=applet;
		this.baseURL=baseURL;
		this.audioFileName=audioFileName;
		setPriority(MIN_PRIORITY);
	}

	public void run()
	{
		audioClip=applet.getAudioClip(baseURL,audioFileName);
		if(audioClip!=null)
		      audioClip.loop();
	}

	public void startPlay()
	{
		if(audioClip!=null)
		    audioClip.loop();
	}

	public void stopPlay()
	{
		if(audioClip!=null)
		      audioClip.stop();
	}
}