我使用JavaCV创建了一个Java应用程序，并且它已成功运行。现在我需要创建一个Applet来访问Web Cam。我知道需要applet签名才能访问Web Cam。我的问题是我尝试使用以下代码创建applet。但它没有用。即GUI没有创建，IDE中没有错误消息。
import static com.googlecode.javacv.cpp.opencv_core.IPL_DEPTH_8U;
import static com.googlecode.javacv.cpp.opencv_core.cvAbsDiff;
import static com.googlecode.javacv.cpp.opencv_core.cvFlip;
import static com.googlecode.javacv.cpp.opencv_imgproc.CV_CHAIN_APPROX_SIMPLE;
import static com.googlecode.javacv.cpp.opencv_imgproc.CV_GAUSSIAN;
import static com.googlecode.javacv.cpp.opencv_imgproc.CV_RETR_LIST;
import static com.googlecode.javacv.cpp.opencv_imgproc.CV_RGB2GRAY;
import static com.googlecode.javacv.cpp.opencv_imgproc.CV_THRESH_BINARY;
import static com.googlecode.javacv.cpp.opencv_imgproc.cvCvtColor;
import static com.googlecode.javacv.cpp.opencv_imgproc.cvFindContours;
import static com.googlecode.javacv.cpp.opencv_imgproc.cvSmooth;
import static com.googlecode.javacv.cpp.opencv_imgproc.cvThreshold;
import java.awt.Color;
import java.awt.event.WindowEvent;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import javax.imageio.ImageIO;
import com.googlecode.javacpp.Loader;
import com.googlecode.javacv.FrameGrabber;
import com.googlecode.javacv.OpenCVFrameGrabber;
import com.googlecode.javacv.FrameGrabber.Exception;
import com.googlecode.javacv.cpp.opencv_core.CvContour;
import com.googlecode.javacv.cpp.opencv_core.CvMemStorage;
import com.googlecode.javacv.cpp.opencv_core.CvSeq;
import com.googlecode.javacv.cpp.opencv_core.IplImage;
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* @author samp
*/
public class VismanWeb extends javax.swing.JApplet
{
/**
* Initializes the applet NewJApplet
*/
private String server="";
private String secur="";
private String ipaddr="";
IplImage frame;
private boolean captFlag=false;
public void start()
{
FrameGrabber grabber = new OpenCVFrameGrabber("");
int height=240,width=320;
grabber.setImageHeight(height);
grabber.setImageWidth(width);
try {
//Start grabber to capture video
grabber.start();
//Declare img as IplImage
IplImage img;
while (true) {
//inser grabed video fram to IplImage img
img = grabber.grab();
if (img != null) {
//Flip image horizontally
cvFlip(img, img, 1);
//Show video frame in canvas
capturePnl.getGraphics().drawImage(img.getBufferedImage(), 0, 0, 320, 240, null);
}
}
}
catch (Exception e) {
}
}
@Override
public void init() {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(VismanWeb.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(VismanWeb.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(VismanWeb.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(VismanWeb.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
try {
java.awt.EventQueue.invokeAndWait(new Runnable() {
public void run() {
initComponents();
}
});
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* This method is called from within the init() method to initialize the
* form. WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
capturePnl = new javax.swing.JPanel();
imagePnl = new javax.swing.JPanel();
captureBtn = new javax.swing.JButton();
getContentPane().setBackground( Color.WHITE );
setMaximumSize(new java.awt.Dimension(360, 560));
setMinimumSize(new java.awt.Dimension(360, 560));
setPreferredSize(new java.awt.Dimension(360, 560));
capturePnl.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0)));
capturePnl.setMaximumSize(new java.awt.Dimension(320, 240));
capturePnl.setMinimumSize(new java.awt.Dimension(320, 240));
capturePnl.setPreferredSize(new java.awt.Dimension(320, 240));
javax.swing.GroupLayout capturePnlLayout = new javax.swing.GroupLayout(capturePnl);
capturePnl.setLayout(capturePnlLayout);
capturePnlLayout.setHorizontalGroup(
capturePnlLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 318, Short.MAX_VALUE)
);
capturePnlLayout.setVerticalGroup(
capturePnlLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 238, Short.MAX_VALUE)
);
imagePnl.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(38, 21, 248)));
imagePnl.setMaximumSize(new java.awt.Dimension(320, 240));
imagePnl.setMinimumSize(new java.awt.Dimension(320, 240));
javax.swing.GroupLayout imagePnlLayout = new javax.swing.GroupLayout(imagePnl);
imagePnl.setLayout(imagePnlLayout);
imagePnlLayout.setHorizontalGroup(
imagePnlLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 320, Short.MAX_VALUE)
);
imagePnlLayout.setVerticalGroup(
imagePnlLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 240, Short.MAX_VALUE)
);
captureBtn.setText("Capture");
captureBtn.setMaximumSize(new java.awt.Dimension(320, 30));
captureBtn.setMinimumSize(new java.awt.Dimension(320, 30));
captureBtn.setPreferredSize(new java.awt.Dimension(320, 30));
captureBtn.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
imagePnl.getGraphics().drawImage(frame.getBufferedImage(), 0, 0,imagePnl.getWidth(), imagePnl.getHeight(), null);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(20, 20, 20)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(imagePnl, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(captureBtn, javax.swing.GroupLayout.PREFERRED_SIZE, 320, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(capturePnl, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(20, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(capturePnl, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(captureBtn, javax.swing.GroupLayout.PREFERRED_SIZE, 40, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(imagePnl, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap())
);
}//
// Variables declaration - do not modify
private javax.swing.JButton captureBtn;
private javax.swing.JPanel capturePnl;
private javax.swing.JPanel imagePnl;
// End of variables declaration
}
请帮我找一个解决方案。或者建议我另一种创建Applet的方法。我使用V4L4J库创建了applet。但它只适用于Linux。我需要在Windows和Linux中工作
答案 0 :(得分：2)
您必须以多线程方式从Applet的start（）方法将bufferedimage添加到任何其他SWING组件的CPanel
public class VismanWeb extends javax.swing.JApplet
{
/**
* Initializes the applet NewJApplet
*/
private String server="";
private String secur="";
private String ipaddr="";
IplImage frame;
OpenCVFrameGrabber grabber;
private boolean captFlag=false;
public void start()
{
Runnable run=new Runnable(){
@Override
public void run()
{
// TODO Auto-generated method stub
grabber = new OpenCVFrameGrabber(0);
try {
grabber.start();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//IplImage grabbedImage = null;
try {
frame = grabber.grab();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//CanvasFrame canvasFrame = new CanvasFrame("Cam");
// canvasFrame.setCanvasSize(grabbedImage.width(), grabbedImage.height());
grabber.setFrameRate(10);
System.out.println("fraamerate = " + grabber.getFrameRate());
try {
while (capturePnl.isVisible() && (frame = grabber.grab()) != null) {
capturePnl.getGraphics().drawImage(frame.getBufferedImage(), 0, 0, 320, 240, null);
//System.out.print("inside\n");
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
grabber.stop();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
};
Thread capture=new Thread(run);
capture.start();
}
@Override
public void init() {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(VismanWeb.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(VismanWeb.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(VismanWeb.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(VismanWeb.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the applet */
try {
java.awt.EventQueue.invokeAndWait(new Runnable() {
public void run() {
initComponents();
}
});
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* This method is called from within the init() method to initialize the
* form. WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
capturePnl = new javax.swing.JPanel();
imagePnl = new javax.swing.JPanel();
captureBtn = new javax.swing.JButton();
getContentPane().setBackground( Color.WHITE );
setMaximumSize(new java.awt.Dimension(360, 560));
setMinimumSize(new java.awt.Dimension(360, 560));
setPreferredSize(new java.awt.Dimension(360, 560));
capturePnl.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0)));
capturePnl.setMaximumSize(new java.awt.Dimension(320, 240));
capturePnl.setMinimumSize(new java.awt.Dimension(320, 240));
capturePnl.setPreferredSize(new java.awt.Dimension(320, 240));
javax.swing.GroupLayout capturePnlLayout = new javax.swing.GroupLayout(capturePnl);
capturePnl.setLayout(capturePnlLayout);
capturePnlLayout.setHorizontalGroup(
capturePnlLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 318, Short.MAX_VALUE)
);
capturePnlLayout.setVerticalGroup(
capturePnlLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 238, Short.MAX_VALUE)
);
imagePnl.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(38, 21, 248)));
imagePnl.setMaximumSize(new java.awt.Dimension(320, 240));
imagePnl.setMinimumSize(new java.awt.Dimension(320, 240));
javax.swing.GroupLayout imagePnlLayout = new javax.swing.GroupLayout(imagePnl);
imagePnl.setLayout(imagePnlLayout);
imagePnlLayout.setHorizontalGroup(
imagePnlLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 320, Short.MAX_VALUE)
);
imagePnlLayout.setVerticalGroup(
imagePnlLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 240, Short.MAX_VALUE)
);
captureBtn.setText("Capture");
captureBtn.setMaximumSize(new java.awt.Dimension(320, 30));
captureBtn.setMinimumSize(new java.awt.Dimension(320, 30));
captureBtn.setPreferredSize(new java.awt.Dimension(320, 30));
captureBtn.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
imagePnl.getGraphics().drawImage(frame.getBufferedImage(), 0, 0,imagePnl.getWidth(), imagePnl.getHeight(), null);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(20, 20, 20)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(imagePnl, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(captureBtn, javax.swing.GroupLayout.PREFERRED_SIZE, 320, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(capturePnl, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(20, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(capturePnl, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(captureBtn, javax.swing.GroupLayout.PREFERRED_SIZE, 40, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(imagePnl, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap())
);
// capt();
}//
//-----------------------------------------------------------------
//-----------------------------------------------------------------
// Variables declaration - do not modify
private javax.swing.JButton captureBtn;
private javax.swing.JPanel capturePnl;
private javax.swing.JPanel imagePnl;
// End of variables declaration
}