easycam.java

来自「在dm642上实现jpeg压缩并可进行网络访问的源码」· Java 代码 · 共 104 行

import java.awt.*;
import java.applet.*;
import java.net.*;

public class easyCam extends Applet {
  private Image  myImage = null;

  private int startIndex = 1;
  private int endIndex = 9;
  private int currentIndex;

  private int sleepTime = 500;

  private String fileBase;
  private String fileExtension;

  private Thread timerThread;
  private volatile boolean noStopRequested;
  private MediaTracker tracker;


  public void init() {
    tracker = new MediaTracker(this);
	String strStartIndex = getParameter("STARTINDEX");
	String strEndIndex   = getParameter("ENDINDEX");
    String strSleepTime  = getParameter("MSDELAY");
    fileBase             = getParameter("FILEBASE");
	fileExtension        = getParameter("FILEEXT");

    if (strStartIndex != null)
	    startIndex = Integer.parseInt(strStartIndex);
    if (strEndIndex != null)
	    endIndex = Integer.parseInt(strEndIndex);
    if (strSleepTime != null)
	    sleepTime = Integer.parseInt(strSleepTime);

    startThread();
  }

  private void startThread() {
    noStopRequested = true;

    Runnable r = new Runnable() {
      public void run() {
        runWork();
      }
    };

    timerThread = new Thread(r, "Timer");
    timerThread.start();
  }

  private void stopThread() {
    noStopRequested = false;
    timerThread.interrupt();
  }

  private void runWork() {
    currentIndex = startIndex;
    boolean imageload = false;

    try {
      while ( noStopRequested ) {
        currentIndex = currentIndex + 1;
        if( currentIndex > endIndex )
          currentIndex = startIndex;

        if( imageload == true ) {
	      tracker.removeImage(myImage);
          myImage.flush();
          myImage = null;
	    }
        myImage = getImage(getDocumentBase(), fileBase + Integer.toString(currentIndex) + fileExtension);
	    tracker.addImage(myImage, 0);
		tracker.waitForAll();
	    imageload = true;

        repaint();

        Thread.sleep( sleepTime );
      }
    } catch ( InterruptedException x ) {
      Thread.currentThread().interrupt();
    }
  }

  public void paint(Graphics g) {
    update(g);
  }

  public void update(Graphics g) {
	if( myImage != null ) {
	  g.drawImage(myImage, 0, 0, this);
    }
  }

  public void destroy() {
    stopThread();

    myImage.flush();
    myImage = null;
  }
}