在我电脑上编译的时候没错,运行的时候总是提示空指针异常
java.lang.NullPointerException
at Camera.jbInit(a.java:123)
at Camera.<init>(a.java:41)
at Camera.main(a.java:114)
import javax.media.Player;
import javax.media.CaptureDeviceInfo;
import javax.media.MediaLocator;
import javax.swing.*;
import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;
import javax.media.control.FrameGrabbingControl;
import javax.media.Buffer;
import javax.media.util.BufferToImage;
import javax.media.format.VideoFormat;
import java.io.*;
import com.sun.image.codec.jpeg.*;
import javax.media.CaptureDeviceManager;
import javax.media.Manager;
import java.net.*;
import java.applet.*;
class Camera extends JFrame
{
private static Player player = null;
private CaptureDeviceInfo device = null;
private MediaLocator locator = null;
private Buffer buffer = null;
private BufferToImage b2i = null;
private Image image = null;
private ImageIcon iicon = new ImageIcon();
boolean proportion = true;
String str1 = "vfw:Logitech USB Video Camera:0";
String str2 = "vfw:Microsoft WDM Image Capture (Win32):0";
JButton jButton1 = new JButton();
JButton jButton2 = new JButton();
Component component1 = null;
JLabel jLabel1 = new JLabel();
public Camera()
{
super("troy的摄像机(无保存功能)");
try
{
jbInit();
}
catch (Exception e)
{
//System.out.println("abc");
e.printStackTrace();
}
} public Image resize(int width, int height, Image source, boolean flag)
{
this.proportion = flag;
int new_w;
int new_h;
Toolkit tk = Toolkit.getDefaultToolkit();
Applet app = new Applet();
MediaTracker mt = new MediaTracker(app);
Image img = source;
try
{
mt.addImage(img, 0);
mt.waitForID(0);
}
catch (Exception e)
{
e.printStackTrace();
}
if (img.getWidth(null) == -1)
{
System.out.println(" can't read,retry!" + "<BR>");
return null;
}
else
{ if (this.proportion == true)
{ //判断是否是等比缩放.
//为等比缩放计算输出的图片宽度及高度
double rate1 = ( (double) img.getWidth(null)) / (double) width + 0.1;
double rate2 = ( (double) img.getHeight(null)) / (double) height + 0.1;
double rate = rate1 > rate2 ? rate1 : rate2;
new_w = (int) ( ( (double) img.getWidth(null)) / rate);
new_h = (int) ( ( (double) img.getHeight(null)) / rate);
}
else
{
new_w = width; //输出的图片宽度
new_h = height; //输出的图片高度
}
}
BufferedImage buffImg = new BufferedImage(new_w, new_h,BufferedImage.TYPE_INT_RGB);
Graphics g = buffImg.createGraphics();
g.setColor(Color.white);
g.fillRect(0, 0, new_w, new_h);
g.drawImage(img, 0, 0, new_w, new_h, null);
g.dispose();
try
{
OutputStream tempout = new FileOutputStream("C:\\temp.jpg");
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(tempout);
encoder.encode(buffImg);
tempout.close(); }
catch (Exception e)
{
e.printStackTrace();
}
return tk.createImage("C:\\temp.jpg");
} public static void main(String[] args)
{
Camera camera1 = new Camera();
} private void jbInit() //throws Exception
{
component1 = Box.createGlue();
//=====================初始化设备===================//
component1.addNotify();
device = CaptureDeviceManager.getDevice(str2);
locator = device.getLocator();
try
{
player = Manager.createRealizedPlayer(locator);
player.start(); if ( (component1 = player.getVisualComponent()) != null)
{
this.getContentPane().add(component1, null);
}
}
catch (Exception e)
{
e.printStackTrace();
} jButton1.setBounds(new Rectangle(294, 28, 73, 25));
jButton1.setText("拍照");
jButton1.addActionListener(new Camera_jButton1_actionAdapter(this));
this.getContentPane().setLayout(null);
jButton2.setBounds(new Rectangle(295, 82, 73, 25));
jButton2.setText("保存");
jButton2.addActionListener(new Camera_jButton2_actionAdapter(this));
component1.setBounds(new Rectangle(27, 23, 243, 235));
jLabel1.setIconTextGap(4);
jLabel1.setText("空");
jLabel1.setVerticalTextPosition(SwingConstants.CENTER); jLabel1.setBounds(new Rectangle(293, 139, 80, 95)); this.getContentPane().add(jButton1, null);
this.getContentPane().add(jButton2, null);
this.getContentPane().add(jLabel1, null);
this.setSize(400, 300);
this.setVisible(true);
} void jButton1_actionPerformed(ActionEvent e)
{
iicon = new ImageIcon();
FrameGrabbingControl fgc = (FrameGrabbingControl) player.getControl("javax.media.control.FrameGrabbingControl");
buffer = fgc.grabFrame(); // 获取当前祯并存入Buffer类
b2i = new BufferToImage( (VideoFormat) buffer.getFormat());
image = b2i.createImage(buffer); // show the image
iicon = new ImageIcon();
/* Toolkit tk = Toolkit.getDefaultToolkit();
Applet app = new Applet();
MediaTracker mt = new MediaTracker(app);*/
iicon.setImage(this.resize(85, 95, image, true));
jLabel1.setIcon(iicon); } void jButton2_actionPerformed(ActionEvent e)
{
JFileChooser filechooser = new JFileChooser();
filechooser.setFileHidingEnabled(true); filechooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
int result = filechooser.showSaveDialog(null);
if (result == JFileChooser.CANCEL_OPTION)
{
return;
}
File file = filechooser.getSelectedFile();
if (file == null || file.getName().equals(""))
{
JOptionPane.showMessageDialog(null, "无效的文件名", "警告",
JOptionPane.ERROR_MESSAGE);
}
else
{
String s = file.getAbsolutePath(); BufferedImage bi = (BufferedImage) createImage(image.getWidth(null),
image.getHeight(null));
Graphics2D g2 = bi.createGraphics();
g2.drawImage(image, null, null);
FileOutputStream out = null;
try
{
out = new FileOutputStream(s);
}
catch (java.io.FileNotFoundException io)
{
System.out.println("File Not Found");
} JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(bi);
param.setQuality(1f, false); //不压缩图像
encoder.setJPEGEncodeParam(param);
try
{
encoder.encode(bi);
out.close();
}
catch (java.io.IOException io)
{
System.out.println("IOException");
}
} }}class Camera_jButton1_actionAdapter implements java.awt.event.ActionListener
{
Camera adaptee; Camera_jButton1_actionAdapter(Camera adaptee)
{
this.adaptee = adaptee;
} public void actionPerformed(ActionEvent e)
{
adaptee.jButton1_actionPerformed(e);
}
}class Camera_jButton2_actionAdapter implements java.awt.event.ActionListener
{
Camera adaptee; Camera_jButton2_actionAdapter(Camera adaptee)
{
this.adaptee = adaptee;
} public void actionPerformed(ActionEvent e)
{
adaptee.jButton2_actionPerformed(e);
}
}
java.lang.NullPointerException
at Camera.jbInit(a.java:123)
at Camera.<init>(a.java:41)
at Camera.main(a.java:114)
import javax.media.Player;
import javax.media.CaptureDeviceInfo;
import javax.media.MediaLocator;
import javax.swing.*;
import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;
import javax.media.control.FrameGrabbingControl;
import javax.media.Buffer;
import javax.media.util.BufferToImage;
import javax.media.format.VideoFormat;
import java.io.*;
import com.sun.image.codec.jpeg.*;
import javax.media.CaptureDeviceManager;
import javax.media.Manager;
import java.net.*;
import java.applet.*;
class Camera extends JFrame
{
private static Player player = null;
private CaptureDeviceInfo device = null;
private MediaLocator locator = null;
private Buffer buffer = null;
private BufferToImage b2i = null;
private Image image = null;
private ImageIcon iicon = new ImageIcon();
boolean proportion = true;
String str1 = "vfw:Logitech USB Video Camera:0";
String str2 = "vfw:Microsoft WDM Image Capture (Win32):0";
JButton jButton1 = new JButton();
JButton jButton2 = new JButton();
Component component1 = null;
JLabel jLabel1 = new JLabel();
public Camera()
{
super("troy的摄像机(无保存功能)");
try
{
jbInit();
}
catch (Exception e)
{
//System.out.println("abc");
e.printStackTrace();
}
} public Image resize(int width, int height, Image source, boolean flag)
{
this.proportion = flag;
int new_w;
int new_h;
Toolkit tk = Toolkit.getDefaultToolkit();
Applet app = new Applet();
MediaTracker mt = new MediaTracker(app);
Image img = source;
try
{
mt.addImage(img, 0);
mt.waitForID(0);
}
catch (Exception e)
{
e.printStackTrace();
}
if (img.getWidth(null) == -1)
{
System.out.println(" can't read,retry!" + "<BR>");
return null;
}
else
{ if (this.proportion == true)
{ //判断是否是等比缩放.
//为等比缩放计算输出的图片宽度及高度
double rate1 = ( (double) img.getWidth(null)) / (double) width + 0.1;
double rate2 = ( (double) img.getHeight(null)) / (double) height + 0.1;
double rate = rate1 > rate2 ? rate1 : rate2;
new_w = (int) ( ( (double) img.getWidth(null)) / rate);
new_h = (int) ( ( (double) img.getHeight(null)) / rate);
}
else
{
new_w = width; //输出的图片宽度
new_h = height; //输出的图片高度
}
}
BufferedImage buffImg = new BufferedImage(new_w, new_h,BufferedImage.TYPE_INT_RGB);
Graphics g = buffImg.createGraphics();
g.setColor(Color.white);
g.fillRect(0, 0, new_w, new_h);
g.drawImage(img, 0, 0, new_w, new_h, null);
g.dispose();
try
{
OutputStream tempout = new FileOutputStream("C:\\temp.jpg");
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(tempout);
encoder.encode(buffImg);
tempout.close(); }
catch (Exception e)
{
e.printStackTrace();
}
return tk.createImage("C:\\temp.jpg");
} public static void main(String[] args)
{
Camera camera1 = new Camera();
} private void jbInit() //throws Exception
{
component1 = Box.createGlue();
//=====================初始化设备===================//
component1.addNotify();
device = CaptureDeviceManager.getDevice(str2);
locator = device.getLocator();
try
{
player = Manager.createRealizedPlayer(locator);
player.start(); if ( (component1 = player.getVisualComponent()) != null)
{
this.getContentPane().add(component1, null);
}
}
catch (Exception e)
{
e.printStackTrace();
} jButton1.setBounds(new Rectangle(294, 28, 73, 25));
jButton1.setText("拍照");
jButton1.addActionListener(new Camera_jButton1_actionAdapter(this));
this.getContentPane().setLayout(null);
jButton2.setBounds(new Rectangle(295, 82, 73, 25));
jButton2.setText("保存");
jButton2.addActionListener(new Camera_jButton2_actionAdapter(this));
component1.setBounds(new Rectangle(27, 23, 243, 235));
jLabel1.setIconTextGap(4);
jLabel1.setText("空");
jLabel1.setVerticalTextPosition(SwingConstants.CENTER); jLabel1.setBounds(new Rectangle(293, 139, 80, 95)); this.getContentPane().add(jButton1, null);
this.getContentPane().add(jButton2, null);
this.getContentPane().add(jLabel1, null);
this.setSize(400, 300);
this.setVisible(true);
} void jButton1_actionPerformed(ActionEvent e)
{
iicon = new ImageIcon();
FrameGrabbingControl fgc = (FrameGrabbingControl) player.getControl("javax.media.control.FrameGrabbingControl");
buffer = fgc.grabFrame(); // 获取当前祯并存入Buffer类
b2i = new BufferToImage( (VideoFormat) buffer.getFormat());
image = b2i.createImage(buffer); // show the image
iicon = new ImageIcon();
/* Toolkit tk = Toolkit.getDefaultToolkit();
Applet app = new Applet();
MediaTracker mt = new MediaTracker(app);*/
iicon.setImage(this.resize(85, 95, image, true));
jLabel1.setIcon(iicon); } void jButton2_actionPerformed(ActionEvent e)
{
JFileChooser filechooser = new JFileChooser();
filechooser.setFileHidingEnabled(true); filechooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
int result = filechooser.showSaveDialog(null);
if (result == JFileChooser.CANCEL_OPTION)
{
return;
}
File file = filechooser.getSelectedFile();
if (file == null || file.getName().equals(""))
{
JOptionPane.showMessageDialog(null, "无效的文件名", "警告",
JOptionPane.ERROR_MESSAGE);
}
else
{
String s = file.getAbsolutePath(); BufferedImage bi = (BufferedImage) createImage(image.getWidth(null),
image.getHeight(null));
Graphics2D g2 = bi.createGraphics();
g2.drawImage(image, null, null);
FileOutputStream out = null;
try
{
out = new FileOutputStream(s);
}
catch (java.io.FileNotFoundException io)
{
System.out.println("File Not Found");
} JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(bi);
param.setQuality(1f, false); //不压缩图像
encoder.setJPEGEncodeParam(param);
try
{
encoder.encode(bi);
out.close();
}
catch (java.io.IOException io)
{
System.out.println("IOException");
}
} }}class Camera_jButton1_actionAdapter implements java.awt.event.ActionListener
{
Camera adaptee; Camera_jButton1_actionAdapter(Camera adaptee)
{
this.adaptee = adaptee;
} public void actionPerformed(ActionEvent e)
{
adaptee.jButton1_actionPerformed(e);
}
}class Camera_jButton2_actionAdapter implements java.awt.event.ActionListener
{
Camera adaptee; Camera_jButton2_actionAdapter(Camera adaptee)
{
this.adaptee = adaptee;
} public void actionPerformed(ActionEvent e)
{
adaptee.jButton2_actionPerformed(e);
}
}
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