Can clock synchronization be implemented by pure java?
I want to build a simple distributed application, whose main purpose is to synchronize the local system clock in the slave JVM with the clock in the master JVM. Can it be implemented by pure java? Or I have to use JNI to implement it?
And although the application is mainly used in LAN, the delay of transferring the data of time is small, but is there any algorithm to minimize the difference of system clock between the master and the slave?
No. You can not synchronize the System Clock (clock) in 100% Pure Java.
Using The Network Time Protocol (NTP) and Java, you can access the current time from many servers around the world.
The problem here is that you can't change the clock through Java without an interface to the actaul clock.
Since the clock is a native component (application, service, or utility) you can't change it while being 100% Pure Java.
That does not mean that you can't do it at all. It just will not be Pure Java. You can, however, test to see what system you are on and then adjust the method used.
On a Windows system, the clock is set by the Control Panel applet "Date and Time." This applet can be updated using the Command Driven Interface (CDI), also known as a Command Prompt. To do this you can use the Java object Process. The parameter, a String value, should point to the location of command prompt. Then add a PrintStream object to the Process object. Send the following line (using PrintStream.println()) - "time" and "date"
To update the time use the following line:
time [ time ]
Use the time format: hh:mm:sec
To update the date use the following line:
date [ date ]
Use the date format: mm-dd-yy
This will work on Windows machines (3.x, 95, 98, Me, NT, XP) MS-DOS (all versions with Date/Time capability).
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Generate a thumbnail from HTML by pure Java on Linux without Graphics
hi - we in a requirement where we have to generate thumbnails from HTML code. The solution must be implemented in pure Java on Linux where there is no graphics support.
Options tried already are :--
1. 3rd party websites - rolled out by our client.
2. Paid products - rolled out by our client
3. Media Tracker and other java API - no luck as there is no support after HTML 4.0
4. Using any os dependent native library - rolled out by our client.
5. Lobo browser - but having troubles like it opens the browser before screenshot is taken, sometimes. Gone through by putting Thread.sleep() in between and saving remote images into a local html file etc. We got some success in there but problem doesn't end here.
Questions -
1. In the point # 5 above, our Linux server had graphics support but in code we set the system property java.awt.headless= true before capturing and generating thumbnail. My question is, if we set this property in the code then does it mean 100% that our code will not use any graphics support, if present in the underlying OS?
2. Is this really possible to generate images in java on Linux where there is no X window/X server installed? Are we just wasting time in order to achieve which is unachievable?
Any suggestions are most welcome.
Regards,
SanjeevThanks for ur response! Yeah - we tried but requirements are little different. We have HTML that we have to first render. Whatever output comes, we have to take a screenshot. So in order to render the html we have to have a browser first and I believe every OS which is providing browser support is having Graphics capabilities because browser would have frames, windows, toolbars, menubars etc which fall under Graphics.
The above way is the only way that I know. If there are another way which ofcourse doesn't require graphics support, please let me know.
So the question basically is - if I follow above mentioned image (like opening browser and capture screenshot) then is it possible on Linux with no graphics support? Actually I read on internet that lobo browser (written in java) supports this kind of feature. -
Technology P2P with JAVA (How can i do for implement this tech with JAVA B)
Thanks for read this message,,, I will glad with you if you can help me...
I would like desing, make, build, a point to point aplication with JAVA Builder, I have been reading about sockets but its not enought,,,,,,
can you help me????
ThanksWell , thanxs for take attention,,,
I need some information about Point to Point tech because I would like to make an aplication with JAVA Builder...
First step is to know how works the point to point...could you give me some links?
Second step is to know how can I do for implement this tech?
Third step is to know Is Java Builder the most indicate languaje for this aplication?
Fourth step is - if Java Buider is the indicate tool, What have to know for make the aplication?
Well,,I dont speak english very well but is the best that i can do?
BYE -
Can I create a cert with the Java API only?
I'm building a client/server app that will use SSL and client certs for authenticating the client to the server. I'd like for each user to be able to create a keypair and an associated self-signed cert that they can provide to the server through some other means, to be included in the server's trust store.
I know how to generate a key pair with an associated self-signed cert via keytool, but I'd prefer to do it directly with the Java APIs. From looking at the Javadocs, I can see how to generate a keypair and how to generate a cert object using an encoded representation of the cert ( e.g. java.security.cert.CertificateFactory.generateCertififcate() ).
But how can I create this encoded representation of the certificate that I need to provide to generateCertificate()? I could do it with keytool and export the cert to a file, but is there no Java API that can accomplish the same thing?
I want to avoid having the user use keytool. Perhaps I can execute the appropriate keytool command from the java code, using Runtime.exec(), but again a pure java API approach would be better. Is there a way to do this all with Java? If not, is executing keytool via Runtime.exec() the best approach?There is no solution available with the JDK. It's rather deficient wrt certificate management, as java.security.cert.CertificateFactory is a factory that only deals in re-treads. That is, it doesn't really create certs. Rather it converts a DER encoded byte stream into a Java Certificate object.
I found two ways to create a certificate from scratch. The first one is an all Java implementation of what keytool does. The second is to use Runtime.exec(), which you don't want to do.
1. Use BouncyCastle, a free open source cryptography library that you can find here: http://www.bouncycastle.org/ There are examples in the documentation that show you how to do just about anything you want to do. I chose not to use it, because my need was satisfied with a lighter approach, and I didn't want to add a dependency unnecessarily. Also Bouncy Castle requires you to use a distinct version with each version of the JDK. So if I wanted my app to work with JDK 1.4 or later, I would have to actually create three different versions, each bundled with the version of BouncyCastle that matches the version of the target JDK.
2. I created my cert by using Runtime.exec() to invoke the keytool program, which you say you don't want to do. This seemed like a hack to me, so I tried to avoid it; but actually I think it was the better choice for me, and I've been happy with how it works. It may have some backward compatibility issues. I tested it on Windows XP and Mac 10.4.9 with JDK 1.6. Some keytool arguments changed with JDK versions, but I think they maintained backward compatibility. I haven't checked it, and I don't know if I'm using the later or earlier version of the keytool arguments.
Here's my code.
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateException;
import javax.security.auth.x500.X500Principal;
import javax.swing.JOptionPane;
public class CreateCertDemo {
private static void createKey() throws IOException,
KeyStoreException, NoSuchAlgorithmException, CertificateException{
X500Principal principal;
String storeName = ".keystore";
String alias = "keyAlias";
principal = PrincipalInfo.getInstance().getPrincipal();
String validity = "10000";
String[] cmd = new String[]{ "keytool", "-genKey", "-alias", alias, "-keyalg", "RSA",
"-sigalg", "SHA256WithRSA", "-dname", principal.getName(), "-validity",
validity, "-keypass", "keyPassword", "-keystore",
storeName, "-storepass", "storePassword"};
int result = doExecCommand(cmd);
if (result != 0){
String msg = "An error occured while trying to generate\n" +
"the private key. The error code returned by\n" +
"the keytool command was " + result + ".";
JOptionPane.showMessageDialog(null, msg, "Key Generation Error", JOptionPane.WARNING_MESSAGE);
KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
ks.load(new FileInputStream(storeName), "storePassword".toCharArray());
//return ks from the method if needed
public static int doExecCommand(String[] cmd) throws IOException{
Runtime r = Runtime.getRuntime();
Process p = null;
p = r.exec(cmd);
FileOutputStream outFos = null;
FileOutputStream errFos = null;
File out = new File("keytool_exe.out");
out.createNewFile();
File err = new File("keytool_exe.err");
err.createNewFile();
outFos = new FileOutputStream(out);
errFos = new FileOutputStream(err);
StreamSink outSink = new StreamSink(p.getInputStream(),"Output", outFos );
StreamSink errSink = new StreamSink(p.getErrorStream(),"Error", errFos );
outSink.start();
errSink.start();
int exitVal = 0;;
try {
exitVal = p.waitFor();
} catch (InterruptedException e) {
return -100;
System.out.println (exitVal==0 ? "certificate created" :
"A problem occured during certificate creation");
outFos.flush();
outFos.close();
errFos.flush();
errFos.close();
out.delete();
err.delete();
return exitVal;
public static void main (String[] args) throws
KeyStoreException, NoSuchAlgorithmException, CertificateException, IOException{
createKey();
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
//Adapted from Mike Daconta's StreamGobbler at
//http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html?page=4
public class StreamSink extends Thread
InputStream is;
String type;
OutputStream os;
public StreamSink(InputStream is, String type)
this(is, type, null);
public StreamSink(InputStream is, String type, OutputStream redirect)
this.is = is;
this.type = type;
this.os = redirect;
public void run()
try
PrintWriter pw = null;
if (os != null)
pw = new PrintWriter(os);
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String line=null;
while ( (line = br.readLine()) != null)
if (pw != null)
pw.println(line);
System.out.println(type + ">" + line);
if (pw != null)
pw.flush();
} catch (IOException ioe)
ioe.printStackTrace();
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import javax.security.auth.x500.X500Principal;
public class PrincipalInfo {
private static String defInfoString = "CN=Name, O=Organization";
//make it a singleton.
private static class PrincipalInfoHolder{
private static PrincipalInfo instance = new PrincipalInfo();
public static PrincipalInfo getInstance(){
return PrincipalInfoHolder.instance;
private PrincipalInfo(){
public X500Principal getPrincipal(){
String fileName = "principal.der";
File file = new File(fileName);
if (file.exists()){
try {
return new X500Principal(new FileInputStream(file));
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return null;
}else{
return new X500Principal(defInfoString);
public void savePrincipal(X500Principal p) throws IOException{
FileOutputStream fos = new FileOutputStream("principal.der");
fos.write(p.getEncoded());
fos.close();
}Message was edited by:
MidnightJava
Message was edited by:
MidnightJava -
How to do implement the FrameAccess.java code in my project
Iam doing an project in java for inserting the videos into oracle9i and searching the inserted videos using the frames of the videos inserted.I have done the project to insert and search the videos.But i have been asked to put an EXTRACT button to extract all the frames of the video being inserted.Please help me to implement the FrameAccess.java coding in my existing coding.I have pasted my coding(VideoInsert.java) and FrameAccess.java(used to extract frames) coding.
The VideoInsert.java when executed will contain browse button to choose the video file(only .mpg files) to be inserted into the database.After selecting the file and when we press open button in the Open dialog box,the video will be played in jmf player in a separate window and the filepath of the video will be included in the textbox.Now what i need is,an extract button should be placed and when it is clicked,the frames of the corresponding selected video has to be extracted in the location where the project files are stored i.e.,the FrameAccess.java coding has to be executed.
Please help me if anyone knows how to implement the above concept.
VideoInsert.java
import javax.swing.*;
import java.util.*;
import java.io.*;
import oracle.sql.*;
import java.sql.*;
import oracle.jdbc.driver.*;
import oracle.sql.BLOB ;
import symantec.itools.multimedia.ImageViewer;
public class VideoInsert extends javax.swing.JFrame {
private Connection con;
private Statement st=null;
private OracleResultSet rs=null;
int count=0;
int count1=0;
ImageViewer displaywindow = new ImageViewer();
/** Creates new form VideoInsert */
public VideoInsert() {
initComponents();
imgpane.add(displaywindow);
try {
DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
con = DriverManager.getConnection("jdbc:oracle:oci:@","scott","tiger");
//con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:FIRST","scott","tiger");
con.setAutoCommit(false);
st =con.createStatement();
rs=(OracleResultSet)st.executeQuery("select max(vid) from browsevideo");
while (rs.next()) {
count = (rs.getInt(1) + 1);
rs.close();
st =con.createStatement();
rs=(OracleResultSet)st.executeQuery("select max(imageno) from browseimage");
while (rs.next()) {
count1 = (rs.getInt(1) + 1);
rs.close();
} catch (SQLException e) {
e.printStackTrace();
txtvid.setText(String.valueOf(count));
VideoTypeComboBox.addItem("All");
VideoTypeComboBox.addItem("Entertainment");
VideoTypeComboBox.addItem("Sports");
VideoTypeComboBox.addItem("Animation");
VideoTypeComboBox.addItem("News");
VideoTypeComboBox.addItem("Others");
/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
private void initComponents() {//GEN-BEGIN:initComponents
jLabel1 = new javax.swing.JLabel();
txtvid = new javax.swing.JTextField();
jLabel2 = new javax.swing.JLabel();
txtvidfile = new javax.swing.JTextField();
jLabel3 = new javax.swing.JLabel();
txtvidinfo = new javax.swing.JTextField();
jLabel4 = new javax.swing.JLabel();
txtimgfile = new javax.swing.JTextField();
vidbrowse = new javax.swing.JButton();
imgbrowse = new javax.swing.JButton();
jLabel5 = new javax.swing.JLabel();
txtimgcont = new javax.swing.JTextField();
insert = new javax.swing.JButton();
imgpane = new javax.swing.JPanel();
jLabel6 = new javax.swing.JLabel();
VideoTypeComboBox = new javax.swing.JComboBox();
getContentPane().setLayout(null);
setTitle("VideoInsert");
addWindowListener(new java.awt.event.WindowAdapter() {
public void windowClosing(java.awt.event.WindowEvent evt) {
exitForm(evt);
jLabel1.setText("Video ID");
getContentPane().add(jLabel1);
jLabel1.setBounds(30, 80, 90, 16);
txtvid.setEditable(false);
getContentPane().add(txtvid);
txtvid.setBounds(130, 80, 130, 20);
jLabel2.setText("VideoFile");
getContentPane().add(jLabel2);
jLabel2.setBounds(30, 130, 70, 16);
getContentPane().add(txtvidfile);
txtvidfile.setBounds(130, 130, 130, 20);
jLabel3.setText("VideoInfo");
getContentPane().add(jLabel3);
jLabel3.setBounds(30, 180, 80, 16);
getContentPane().add(txtvidinfo);
txtvidinfo.setBounds(130, 180, 130, 20);
jLabel4.setText("TopImage");
getContentPane().add(jLabel4);
jLabel4.setBounds(30, 230, 70, 16);
getContentPane().add(txtimgfile);
txtimgfile.setBounds(130, 230, 130, 20);
vidbrowse.setText("Browse");
vidbrowse.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
vidbrowseActionPerformed(evt);
getContentPane().add(vidbrowse);
vidbrowse.setBounds(280, 130, 78, 26);
imgbrowse.setText("Browse");
imgbrowse.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
imgbrowseActionPerformed(evt);
getContentPane().add(imgbrowse);
imgbrowse.setBounds(280, 230, 78, 26);
jLabel5.setText("ImageContent");
getContentPane().add(jLabel5);
jLabel5.setBounds(30, 280, 80, 16);
getContentPane().add(txtimgcont);
txtimgcont.setBounds(130, 280, 130, 20);
insert.setText("Insert");
insert.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
insertActionPerformed(evt);
getContentPane().add(insert);
insert.setBounds(150, 400, 81, 26);
imgpane.setLayout(new java.awt.BorderLayout());
getContentPane().add(imgpane);
imgpane.setBounds(410, 120, 350, 260);
jLabel6.setText("Video Type");
getContentPane().add(jLabel6);
jLabel6.setBounds(30, 340, 80, 16);
getContentPane().add(VideoTypeComboBox);
VideoTypeComboBox.setBounds(130, 340, 130, 25);
pack();
java.awt.Dimension screenSize = java.awt.Toolkit.getDefaultToolkit().getScreenSize();
setSize(new java.awt.Dimension(800, 600));
setLocation((screenSize.width-800)/2,(screenSize.height-600)/2);
}//GEN-END:initComponents
private void insertActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_insertActionPerformed
BLOB blb= null;
PreparedStatement stmt = null;
OutputStream fout=null;
File f=null;
FileInputStream fin=null;
int bufferSize;
byte[] buffer=null;
int bytesRead = -1;
String sfile1 = txtvidfile.getText();
String sfile2 = txtimgfile.getText();
String format=null;
String format1=null;
String videoinfo=txtvidinfo.getText();
String imgcontent=txtimgcont.getText();
String videoType=(String)VideoTypeComboBox.getSelectedItem();
if(sfile1.endsWith("avi")) {
format="avi";
}else if(sfile1.endsWith("mpg")) {
format="mpg";
}else {
format="mpg";
if(sfile2.endsWith("jpg")) {
format1="jpg";
}else if(sfile2.endsWith("gif")) {
format1="gif";
}else {
format1="jpg";
if((sfile1.length()>0) && (sfile2.length()>0)) {
try {
stmt=con.prepareStatement(" insert into browsevideo values (?,EMPTY_BLOB(),?,?,?)");
stmt.setInt(1,count);
stmt.setString(2,format);
stmt.setString(3,videoinfo);
stmt.setString(4,videoType);
stmt.executeUpdate();
stmt.close();
con.commit();
}catch(Exception e) {
e.printStackTrace();
try {
stmt = con.prepareStatement("Select video FROM browsevideo WHERE vid = ? for update of video");
stmt.setInt(1,count);
rs = (OracleResultSet)stmt.executeQuery();
rs.next();
blb = rs.getBLOB("video");
fout = blb.getBinaryOutputStream();
f = new File(sfile1);
fin = new FileInputStream(f);
bufferSize = blb.getBufferSize();
buffer = new byte[bufferSize];
while((bytesRead = fin.read(buffer)) != -1) {
fout.write(buffer, 0, bytesRead);
fout.flush();
fout.close();
con.commit();
rs.close();
stmt.close();
}catch(Exception e) {
e.printStackTrace();
try {
stmt=con.prepareStatement(" insert into browseimage values (?,?,?,EMPTY_BLOB(),?,?,?)");
stmt.setInt(1,count);
stmt.setInt(2,count1);
stmt.setInt(3,count1);
stmt.setString(4,imgcontent);
stmt.setString(5,format1);
stmt.setString(6,videoType);
stmt.executeUpdate();
stmt.close();
con.commit();
}catch(Exception e) {
e.printStackTrace();
try {
stmt = con.prepareStatement("Select image FROM browseimage WHERE imageno = ? for update of image");
stmt.setInt(1,count1);
rs = (OracleResultSet)stmt.executeQuery();
if(rs.next()) {
blb = rs.getBLOB("image");
fout = blb.getBinaryOutputStream();
f = new File(sfile2);
fin = new FileInputStream(f);
bufferSize = blb.getBufferSize();
buffer = new byte[bufferSize];
while((bytesRead = fin.read(buffer)) != -1) {
fout.write(buffer, 0, bytesRead);
fout.flush();
fout.close();
con.commit();
rs.close();
stmt.close();
count++;
count1++;
txtimgfile.setText("");
txtvidfile.setText("");
txtimgcont.setText("");
txtvidinfo.setText("");
txtvid.setText(String.valueOf(count));
JOptionPane.showMessageDialog(this,"Successfuly Completed");
}catch(Exception e) {
e.printStackTrace();
}//GEN-LAST:event_insertActionPerformed
private void imgbrowseActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_imgbrowseActionPerformed
ExampleFileFilter filter1 = new ExampleFileFilter();
JFileChooser chooser = new JFileChooser();
filter1.addExtension("jpg");
filter1.addExtension("gif");
filter1.setDescription("JPG,GIF Images");
chooser.setFileFilter(filter1);
int returnVal = chooser.showOpenDialog(this);
if(returnVal == JFileChooser.APPROVE_OPTION) {
txtimgfile.setText(chooser.getSelectedFile().getAbsolutePath());
try{
displaywindow.setImageURL(new java.net.URL("file:"+txtimgfile.getText()));
displaywindow.setStyle(ImageViewer.IMAGE_SCALED_TO_FIT);
}catch(Exception e){
e.printStackTrace();
}//GEN-LAST:event_imgbrowseActionPerformed
private void vidbrowseActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_vidbrowseActionPerformed
ExampleFileFilter filter2 = new ExampleFileFilter();
JFileChooser chooser = new JFileChooser();
filter2.addExtension("avi");
filter2.addExtension("mpg");
filter2.setDescription("AVI & MPG Video");
chooser.setFileFilter(filter2);
int returnVal = chooser.showOpenDialog(this);
if(returnVal == JFileChooser.APPROVE_OPTION) {
txtvidfile.setText(chooser.getSelectedFile().getAbsolutePath());
VideoAudioPlayer vap=new VideoAudioPlayer(txtvidfile.getText());
}//GEN-LAST:event_vidbrowseActionPerformed
/** Exit the Application */
private void exitForm(java.awt.event.WindowEvent evt) {//GEN-FIRST:event_exitForm
setVisible(false);
dispose();
}//GEN-LAST:event_exitForm
* @param args the command line arguments
/*public static void main(String args[]) {
new VideoInsert().show();
// Variables declaration - do not modify//GEN-BEGIN:variables
private javax.swing.JButton imgbrowse;
private javax.swing.JLabel jLabel4;
private javax.swing.JTextField txtvid;
private javax.swing.JLabel jLabel1;
private javax.swing.JTextField txtimgcont;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel2;
private javax.swing.JPanel imgpane;
private javax.swing.JButton insert;
private javax.swing.JComboBox VideoTypeComboBox;
private javax.swing.JButton vidbrowse;
private javax.swing.JTextField txtvidfile;
private javax.swing.JLabel jLabel6;
private javax.swing.JLabel jLabel5;
private javax.swing.JTextField txtimgfile;
private javax.swing.JTextField txtvidinfo;
// End of variables declaration//GEN-END:variables
FrameAccess.java
import java.awt.*;
import javax.media.*;
import javax.media.control.TrackControl;
import javax.media.Format;
import javax.media.format.*;
import java.io.*;
import javax.imageio.*;
import javax.imageio.stream.*;
import java.awt.image.*;
import java.util.*;
import javax.media.util.*;
* Sample program to access individual video frames by using a
* "pass-thru" codec. The codec is inserted into the data flow
* path. As data pass through this codec, a callback is invoked
* for each frame of video data.
public class FrameAccess implements ControllerListener {
Processor p;
Object waitSync = new Object();
boolean stateTransitionOK = true;
public boolean alreadyPrnt = false;
* Given a media locator, create a processor and use that processor
* as a player to playback the media.
* During the processor's Configured state, two "pass-thru" codecs,
* PreAccessCodec and PostAccessCodec, are set on the video track.
* These codecs are used to get access to individual video frames
* of the media.
* Much of the code is just standard code to present media in JMF.
public boolean open(MediaLocator ml) {
try {
p = Manager.createProcessor(ml);
} catch (Exception e) {
System.err.println(
"Failed to create a processor from the given url: " + e);
return false;
p.addControllerListener(this);
// Put the Processor into configured state.
p.configure();
if (!waitForState(Processor.Configured)) {
System.err.println("Failed to configure the processor.");
return false;
// So I can use it as a player.
p.setContentDescriptor(null);
// Obtain the track controls.
TrackControl tc[] = p.getTrackControls();
if (tc == null) {
System.err.println(
"Failed to obtain track controls from the processor.");
return false;
// Search for the track control for the video track.
TrackControl videoTrack = null;
for (int i = 0; i < tc.length; i++) {
if (tc.getFormat() instanceof VideoFormat) videoTrack = tc[i];
else tc[i].setEnabled(false);
if (videoTrack == null) {
System.err.println("The input media does not contain a video track.");
return false;
String videoFormat = videoTrack.getFormat().toString();
Dimension videoSize = parseVideoSize(videoFormat);
System.err.println("Video format: " + videoFormat);
// Instantiate and set the frame access codec to the data flow path.
try {
Codec codec[] = { new PostAccessCodec(videoSize)};
videoTrack.setCodecChain(codec);
} catch (UnsupportedPlugInException e) {
System.err.println("The process does not support effects.");
// Realize the processor.
p.prefetch();
if (!waitForState(Processor.Prefetched)) {
System.err.println("Failed to realise the processor.");
return false;
p.start();
return true;
/**parse the size of the video from the string videoformat*/
public Dimension parseVideoSize(String videoSize){
int x=300, y=200;
StringTokenizer strtok = new StringTokenizer(videoSize, ", ");
strtok.nextToken();
String size = strtok.nextToken();
StringTokenizer sizeStrtok = new StringTokenizer(size, "x");
try{
x = Integer.parseInt(sizeStrtok.nextToken());
y = Integer.parseInt(sizeStrtok.nextToken());
} catch (NumberFormatException e){
System.out.println("unable to find video size, assuming default of 300x200");
System.out.println("Image width = " + String.valueOf(x) +"\nImage height = "+ String.valueOf(y));
return new Dimension(x, y);
* Block until the processor has transitioned to the given state.
* Return false if the transition failed.
boolean waitForState(int state) {
synchronized (waitSync) {
try {
while (p.getState() != state && stateTransitionOK)
waitSync.wait();
} catch (Exception e) {
return stateTransitionOK;
* Controller Listener.
public void controllerUpdate(ControllerEvent evt) {
if (evt instanceof ConfigureCompleteEvent
|| evt instanceof RealizeCompleteEvent
|| evt instanceof PrefetchCompleteEvent) {
synchronized (waitSync) {
stateTransitionOK = true;
waitSync.notifyAll();
} else if (evt instanceof ResourceUnavailableEvent) {
synchronized (waitSync) {
stateTransitionOK = false;
waitSync.notifyAll();
} else if (evt instanceof EndOfMediaEvent) {
p.close();
System.exit(0);
* Main program
public static void main(String[] args) {
// if (args.length == 0) {
// prUsage();
// System.exit(0);
// System.out.print("masoud");
String url = new String("file:F:\\AVSEQ01.mpg");
if (url.indexOf(":") < 0) {
prUsage();
System.exit(0);
MediaLocator ml;
if ((ml = new MediaLocator(url)) == null) {
System.err.println("Cannot build media locator from: " + url);
System.exit(0);
FrameAccess fa = new FrameAccess();
if (!fa.open(ml))
System.exit(0);
static void prUsage() {
System.err.println("Usage: java FrameAccess <url>");
* Inner class.
* A pass-through codec to access to individual frames.
public class PreAccessCodec implements Codec {
* Callback to access individual video frames.
void accessFrame(Buffer frame) {
// For demo, we'll just print out the frame #, time &
// data length.
long t = (long) (frame.getTimeStamp() / 10000000f);
System.err.println(
"Pre: frame #: "
+ frame.getSequenceNumber()
+ ", time: "
+ ((float) t) / 100f
+ ", len: "
+ frame.getLength());
* The code for a pass through codec.
// We'll advertize as supporting all video formats.
protected Format supportedIns[] = new Format[] { new VideoFormat(null)};
// We'll advertize as supporting all video formats.
protected Format supportedOuts[] = new Format[] { new VideoFormat(null)};
Format input = null, output = null;
public String getName() {
return "Pre-Access Codec";
//these dont do anything
public void open() {}
public void close() {}
public void reset() {}
public Format[] getSupportedInputFormats() {
return supportedIns;
public Format[] getSupportedOutputFormats(Format in) {
if (in == null)
return supportedOuts;
else {
// If an input format is given, we use that input format
// as the output since we are not modifying the bit stream
// at all.
Format outs[] = new Format[1];
outs[0] = in;
return outs;
public Format setInputFormat(Format format) {
input = format;
return input;
public Format setOutputFormat(Format format) {
output = format;
return output;
public int process(Buffer in, Buffer out) {
// This is the "Callback" to access individual frames.
accessFrame(in);
// Swap the data between the input & output.
Object data = in.getData();
in.setData(out.getData());
out.setData(data);
// Copy the input attributes to the output
out.setFlags(Buffer.FLAG_NO_SYNC);
out.setFormat(in.getFormat());
out.setLength(in.getLength());
out.setOffset(in.getOffset());
return BUFFER_PROCESSED_OK;
public Object[] getControls() {
return new Object[0];
public Object getControl(String type) {
return null;
public class PostAccessCodec extends PreAccessCodec {
// We'll advertize as supporting all video formats.
public PostAccessCodec(Dimension size) {
supportedIns = new Format[] { new RGBFormat()};
this.size = size;
* Callback to access individual video frames.
void accessFrame(Buffer frame) {
// For demo, we'll just print out the frame #, time &
// data length.
if (!alreadyPrnt) {
BufferToImage stopBuffer = new BufferToImage((VideoFormat) frame.getFormat());
Image stopImage = stopBuffer.createImage(frame);
try {
BufferedImage outImage = new BufferedImage(size.width, size.height, BufferedImage.TYPE_INT_RGB);
Graphics og = outImage.getGraphics();
og.drawImage(stopImage, 0, 0, size.width, size.height, null);
//prepareImage(outImage,rheight,rheight, null);
Iterator writers = ImageIO.getImageWritersByFormatName("jpg");
ImageWriter writer = (ImageWriter) writers.next();
//Once an ImageWriter has been obtained, its destination must be set to an ImageOutputStream:
File f = new File(frame.getSequenceNumber() + ".jpg");
ImageOutputStream ios = ImageIO.createImageOutputStream(f);
writer.setOutput(ios);
//Finally, the image may be written to the output stream:
//BufferedImage bi;
//writer.write(imagebi);
writer.write(outImage);
ios.close();
} catch (IOException e) {
System.out.println("Error :" + e);
//alreadyPrnt = true;
long t = (long) (frame.getTimeStamp() / 10000000f);
System.err.println(
"Post: frame #: "
+ frame.getSequenceNumber()
+ ", time: "
+ ((float) t) / 100f
+ ", len: "
+ frame.getLength());
public String getName() {
return "Post-Access Codec";
private Dimension size;check out the java.lang.Runtime and java.lang.Process classes
-
NewBie Question: Can you make a website completely with Java?
Greetings my new Fellow Java programmers. My name is Jason and I am a computer programmer and web developer. I am verse in the following:
1. HTML/XHTML
2. CSS
3. Asp.net
4. VB.Net
5. SQL
I want to expand my skills to include:
1.JAVA
2. Action Script
3. Java Script
4. Ajax
I have always wanted to learn Java and now I think it is the right time. So my question is can you create a site complete with Java or have a majority of the site functions and look attributed to Java? Is it similar to creating a site with vb.net and asp.net which utilizes html as well? Please explain. I am eager to learn this language. Thank you.
-RomDog
...ROOOOOF!RomDog wrote:
Is it similar to creating a site with vb.net and asp.net which utilizes html as well? Please explain. I am eager to learn this language. Thank you.
I find it strange that you have to ask this. Of course the end result will be HTML/XHTML, that's what the browsers want. I would think that if you know the .NET side of web development, these concepts (client/server technologies) should already be clear to you.
The short answer is yes it is possible. However if you want to learn Ajax/Javascript/Actionscript, I would learn those technologies before you learn Java web development as they are completely unrelated. You know that Javascript is not Java, right? You can implement javascript/Ajax in your .NET web applications already.
Before you want to learn Java web development, learn Java. Seriously, learn basic Java first. It will be a great deal harder (and ultimately a lot more frustrating) to jump directly into the web development side of Java without knowing any of the basics. One of the biggest differences between .NET and Java platforms is that Microsoft basically holds your hand when it comes to making decision about which APIs to use and how to attack a problem; Java leaves you to the wolves to select from a gigantic amount of APIs and tools available that can each solve a problem in their very own way. Freedom is great, but it can be very daunting when you are just beginning.
So before you even think about web development, I suggest you explore the java tutorial and see if you can get to grips with the language and the tool set.
[http://java.sun.com/docs/books/tutorial/|http://java.sun.com/docs/books/tutorial/]
When you are comfortable with the Java language and you are sure that Java web/enterprise development is still something for you, then come back and ask the question again. -
How can I use XStream to persist complicated Java Object to XML & backward
Dear Sir:
I met a problem as demo in my code below when i use XTream to persist my Java Object;
How can I use XStream to persist complicated Java Object to XML & backward??
See
[1] main code
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.xml.DomDriver;
public class PhoneList {
ArrayList<PhoneNumber> phones;
ArrayList<Person> person;
private PhoneList myphonelist ;
private LocationTest location;
private PhoneList(String name) {
phones = new ArrayList<PhoneNumber>();
person = new ArrayList<Person>();
public ArrayList<PhoneNumber> getphones() {
return phones;
public ArrayList<Person> getperson() {
return person;
public void addPhoneNumber(PhoneNumber b1) {
this.phones.add(b1);
public void removePhoneNumber(PhoneNumber b1) {
this.phones.remove(b1);
public void addPerson(Person p1) {
this.person.add(p1);
public void removePerson(Person p1) {
this.person.remove(p1);
public void BuildList(){
location = new LocationTest();
XStream xstream = new XStream();
myphonelist = new PhoneList("PhoneList");
Person joe = new Person("Joe, Wallace");
joe.setPhone(new PhoneNumber(123, "1234-456"));
joe.setFax(new PhoneNumber(123, "9999-999"));
Person geo= new Person("George Nixson");
geo.setPhone(new PhoneNumber(925, "228-9999"));
geo.getPhone().setLocationTest(location);
myphonelist.addPerson(joe);
myphonelist.addPerson(geo);
public PhoneList(){
XStream xstream = new XStream();
BuildList();
saveStringToFile("C:\\temp\\test\\PhoneList.xml",convertToXML(myphonelist));
public void saveStringToFile(String fileName, String saveString) {
BufferedWriter bw = null;
try {
bw = new BufferedWriter(
new FileWriter(fileName));
try {
bw.write(saveString);
finally {
bw.close();
catch (IOException ex) {
ex.printStackTrace();
//return saved;
public String getStringFromFile(String fileName) {
BufferedReader br = null;
StringBuilder sb = new StringBuilder();
try {
br = new BufferedReader(
new FileReader(fileName));
try {
String s;
while ((s = br.readLine()) != null) {
// add linefeed (\n) back since stripped by readline()
sb.append(s + "\n");
finally {
br.close();
catch (Exception ex) {
ex.printStackTrace();
return sb.toString();
public String convertToXML(PhoneList phonelist) {
XStream xstream = new XStream(new DomDriver());
xstream.setMode(xstream.ID_REFERENCES) ;
return xstream.toXML(phonelist);
public static void main(String[] args) {
new PhoneList();
}[2].
import java.io.Serializable;
import javax.swing.JFrame;
public class PhoneNumber implements Serializable{
private String phone;
private String fax;
private int code;
private String number;
private String address;
private String school;
private LocationTest location;
public PhoneNumber(int i, String str) {
setCode(i);
setNumber(str);
address = "4256, Washington DC, USA";
school = "Washington State University";
public Object getPerson() {
return null;
public void setPhone(String phone) {
this.phone = phone;
public String getPhone() {
return phone;
public void setFax(String fax) {
this.fax = fax;
public String getFax() {
return fax;
public void setCode(int code) {
this.code = code;
public int getCode() {
return code;
public void setNumber(String number) {
this.number = number;
public String getNumber() {
return number;
public void setLocationTest(LocationTest bd) {
this.location = bd;
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add(location);
f.getContentPane().add(location.getControls(), "Last");
f.setSize(400,400);
f.setLocation(200,200);
f.setVisible(true);
public LocationTest getLocationTest() {
return location;
}[3].
package test.temp;
import java.io.Serializable;
public class Person implements Serializable{
private String fullname;
@SuppressWarnings("unused")
private PhoneNumber phone;
@SuppressWarnings("unused")
private PhoneNumber fax;
public Person(){
public Person(String fname){
fullname=fname;
public void setPhone(PhoneNumber phoneNumber) {
phone = phoneNumber;
public void setFax(PhoneNumber phoneNumber) {
fax = phoneNumber;
public PhoneNumber getPhone() {
return phone ;
public PhoneNumber getFax() {
return fax;
public String getName() {
return fullname ;
public void setName(String name) {
this.fullname = name;
public String toString() {
return getName();
}[4]. LocationTest.java
package test.temp;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;
import javax.swing.event.*;
public class LocationTest extends JPanel implements ChangeListener
Ellipse2D.Double ball;
Line2D.Double line;
JSlider translate;
double lastTheta = 0;
public void stateChanged(ChangeEvent e)
JSlider slider = (JSlider)e.getSource();
String name = slider.getName();
int value = slider.getValue();
if(name.equals("rotation"))
tilt(Math.toRadians(value));
else if(name.equals("translate"))
moveBall(value);
repaint();
protected void paintComponent(Graphics g)
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
if(ball == null)
initGeom();
g2.setPaint(Color.green.darker());
g2.draw(line);
g2.setPaint(Color.red);
g2.fill(ball);
private void initGeom()
int w = getWidth();
int h = getHeight();
int DIA = 30;
int padFromEnd = 5;
line = new Line2D.Double(w/4, h*15/16, w*3/4, h*15/16);
double x = line.x2 - padFromEnd - DIA;
double y = line.y2 - DIA;
ball = new Ellipse2D.Double(x, y, DIA, DIA);
// update translate slider values
int max = (int)line.getP1().distance(line.getP2());
translate.setMaximum(max);
translate.setValue(max-padFromEnd);
private void tilt(double theta)
// rotate line from left end
Point2D pivot = line.getP1();
double lineLength = pivot.distance(line.getP2());
Point2D.Double p2 = new Point2D.Double();
p2.x = pivot.getX() + lineLength*Math.cos(theta);
p2.y = pivot.getY() + lineLength*Math.sin(theta);
line.setLine(pivot, p2);
// find angle from pivot to ball center relative to line
// ie, ball center -> pivot -> line end
double cx = ball.getCenterX();
double cy = ball.getCenterY();
double pivotToCenter = pivot.distance(cx, cy);
// angle of ball to horizon
double dy = cy - pivot.getY();
double dx = cx - pivot.getX();
// relative angle phi = ball_to_horizon - last line_to_horizon
double phi = Math.atan2(dy, dx) - lastTheta;
// rotate ball from pivot
double x = pivot.getX() + pivotToCenter*Math.cos(theta+phi);
double y = pivot.getY() + pivotToCenter*Math.sin(theta+phi);
ball.setFrameFromCenter(x, y, x+ball.width/2, y+ball.height/2);
lastTheta = theta; // save theta for next time
private void moveBall(int distance)
Point2D pivot = line.getP1();
// ball touches line at distance from pivot
double contactX = pivot.getX() + distance*Math.cos(lastTheta);
double contactY = pivot.getY() + distance*Math.sin(lastTheta);
// find new center location of ball
// angle lambda = lastTheta - 90 degrees (anti-clockwise)
double lambda = lastTheta - Math.PI/2;
double x = contactX + (ball.width/2)*Math.cos(lambda);
double y = contactY + (ball.height/2)*Math.sin(lambda);
ball.setFrameFromCenter(x, y, x+ball.width/2, y+ball.height/2);
JPanel getControls()
JSlider rotate = getSlider("rotation angle", "rotation", -90, 0, 0, 5, 15);
translate = getSlider("distance from end", "translate", 0, 100, 100,25, 50);
JPanel panel = new JPanel(new GridLayout(0,1));
panel.add(rotate);
panel.add(translate);
return panel;
private JSlider getSlider(String title, String name, int min, int max,
int value, int minorSpace, int majorSpace)
JSlider slider = new JSlider(JSlider.HORIZONTAL, min, max, value);
slider.setBorder(BorderFactory.createTitledBorder(title));
slider.setName(name);
slider.setPaintTicks(true);
slider.setMinorTickSpacing(minorSpace);
slider.setMajorTickSpacing(majorSpace);
slider.setPaintLabels(true);
slider.addChangeListener(this);
return slider;
}OK, My questions are:
[1]. what I generated XML by XSTream is very complicated, especially for object LocationTest, Can we make it as simple as others such as Person object??
[2]. after I run it, LocationTest will popup and a red ball in a panel will dsiplay, after I change red ball's position, I hope to persist it to xml, then when I read it back, I hope to get same picture, ie, red ball stiil in old position, How to do that??
Thanks a lot!!Positive feedback? Then please take this in a positive way: if you want to work on persisting Java objects into XML, then GUI programming is irrelevant to that goal. The 1,000 lines of code you posted there appeared to me to have a whole lot of GUI code in it. You should produce a smaller (much smaller) example of what you want to do. Calling the working code from your GUI program should come later.
-
The client is a pure-Java client, how to invoke session bean in oc4j server
I WOULD LIKE TO INVOKE MY SESSION BEAN FROM MY STRUT WEB PROJECT AS A PURE JAVA CLIENT . I SETUP THE JNDI INITIAL CONTEXT PROPERTY BUT I HAVE NO IDEA TO WHERE I SHALL PUT MY application-client.xml and orion-application-client.xml. MY APPLICATION THROW EXCEPTION
NamingException: StoreEJB not found
IF YOU ANY EXAMPLE PLEASE SEND ME
THIS IS MY CLIENT PROGRAME
package ejbs;
import java.io.*;
import javax.ejb.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.naming.*;
import javax.rmi.*;
import java.rmi.*;
import java.util.*;
public class StrutInt {
* @param args
public static void main(String[] args) {
//System.out.print("The application Checkup");
try
Hashtable env = new Hashtable();
env.put (Context.INITIAL_CONTEXT_FACTORY,
"oracle.j2ee.naming.ApplicationClientInitialContextFactory");
env.put (Context.SECURITY_PRINCIPAL, "oc4jadmin");
env.put (Context.SECURITY_CREDENTIALS, "admin");
//env.put (Context.PROVIDER_URL, "http://localhost:8888");
env.put (Context.PROVIDER_URL, "ormi://localhost:23791/EjbIntegrationEAR");
env.put ("dedicated.rmicontext", "true"); // for 9.0.2.1 and above
Context context = new InitialContext (env);
System.out.println("work up to this");
Object homeObject =
context.lookup("StoreEJB");
System.out.print("Hi Integration");
StoreHome storeHome = (StoreHome) PortableRemoteObject
.narrow(homeObject, StoreHome.class);
Store exa= storeHome.create();
String s =exa.foo("The foul guy");
System.out.print(s);
catch(NamingException e1) {
System.err.println("NamingException: " + e1.getMessage());
catch(RemoteException e2) {
System.err.println("RemoteException: " + e2.getMessage());
catch(CreateException e3) {
System.err.println("FinderException: " + e3.getMessage());
catch(Exception e4) {
System.err.println("FinderException: " + e4.getMessage());
}Create the object of InitialContest class. Then pass in hashTable put WLContextFactory.
then lookup to the sessionJNDI. then call the create method u will get the remote object, from the remote object u can call to the business method -
Is There A Pure Java Solution?
Is there a pure Java solution for a servlet to create
a popup window? In other words, is there a Java solution
for creating a new window with Java code inside the
doPost() method?Try setting
response.setContentType("text/html");
response.setStatus(HttpServletResponse.SC_PARTIAL_CONTENT);
and stream html with javascript to pop a window. Don't have code right now...but try to search in this direction. Sure you can do...I will post the code if I find..
- -
How can i have a refrence of a java class object instance in my c++ project
Hi!
How can i have a refrence of a java class object instance in my c++ project. Is there a way?hahaxia wrote:
The second question is the big one. The first question is half of the problem of "c++ to java" invocation and access. But the other half which is "java to c++ " invocation and access is still not solved. jni only provide the "java to c++ " DLL invocation Wrong,
Using JNI your java classes can have methods implemented in C/C++.
Using JNI you can call java classes.
There is no other possible interaction between C++ and java, so it does it all. -
How to deploy a pure jave development component to server?
i have created a pure java development component.
but i cannot find a way to deploy it to server
is there any way?You need to essencially wrap your java development component with a deployable development component.
In order to do that, you need to:
- Define a public part for your development component of type assembly.
- Create a deployable DC ( one that results in a SDA or a EAR file ).
- Reference your DC from the deployable DC. This will include the generated .jar file into the project.
The definitions of the different types can be found here:
http://help.sap.com/saphelp_nw04/helpdata/en/93/d5a73f05c4265de10000000a114084/content.htm
I would either create a library component ( results in SDA ) or a web dynpro component ( ear file ). -
How can I compact a MSAccess database with java?
Hi.
I have a question (Please Help!!!):
How can I compact a MSAccess database with java-jdbc? Is it posible?
ThanksMS Access database has a max length limitation of 2.14GB for Access 2000( 1.07G for Access 97), and won't recycle basically space for update/delete sql so tha it's a good idea to use MS Access database for program, which need update/delete frequent ly data. The programmers of HXTT Access(www.hxtt.net) are writing code for CREATE TABLE/DATABASE sql now. If you need a pure Java solution for PACK TABLE/DATABSE urgently in your project, you should send such a requirement to the Support page of www.hxtt.net so that they can schedule complementing such a fucntion. Otherwise, you should pack your databae manually or visit C++ code for Compact an Access Database Programmatically at
http://www.codeguru.com/Cpp/data/mfc_database/microsoftaccess/article.php/c4327/ , or use Easy Microsoft Access MDB MDE Compactor at http://www.easyhr.com.au/software/easy_mdb_mde_compactor.htm. -
How to implement hyperlink in java using swing components
hi.....
pls help me to find out solution
how to implement hyperlink in java using swing componentsI've got the same problem here.
I want to implement a HyperlinkListener to a JLabel. (Unlike suggested above, it is only supported by JEditorPane and not JLabel)
The goal is, that if a user clicks on a Link in a JLabel, the standard browser opens and displays that page.
Can somebody please help?
My ultimate goal would be to also be able to add clickable HyperLinks in ToolTip texts, but i guess that'd be even more complicated. -
How can the diamond problem be fixed in java
How can the diamond problem be fixed in java?
aksarben wrote:
I assume he's referring to this:We all assumed he's referring to that. But since Java doesn't have multiple inheritance of implementation, there is no diamond problem in Java (per se). -
Could not load mediaLib accelerator wrapper classes. Continuing in pure Jav
Can anyone provide an explanation/solution to the following error message:
"Could not load mediaLib accelerator wrapper classes. Continuing in pure Java mode."This problem seems to occur if only the JAI JAR files are installed without the native DLL's. Is there some property that can be passed in to JAI so that it doesn't look for the DLL's? The lookup is causing quite a delay in initial server response time. We don't want to include the DLL's since they are a big pain for our customers to install and the performance issue is not a concern.
Thanks for any help!
-Matt
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