I am trying to print out all of the capture devices that are supported using the #getDeviceList() method in the CaptureDeviceManager class and the returned Vector has a size of 0.
Why is that? I have a webcam that works - so there should be at least one. I am running Mac OS X Lion - using JMF 2.1.1e.
Thanks!
CaptureDeviceManager.getDeviceList(Format format) does not detect devices. Instead it reads from the JMF registry which is the jmf.properties file. It searches for the jmf.properties file in the classpath.
If your JMF install has succeeded, then the classpath would have been configured to include all the relevant JMF jars and directories. The JMF install comes with a jmf.properties file included in the 'lib' folder under the JMF installation directory. This means the jmf.properties would be located by JMStudio and you would usually see the JMStudio application executing correctly. (If your JMF install is under 'C:\Program Files', then run as administrator to get around UAC)
When you create your own application to detect the devices, the problem you described above might occur. I have seen a few questions related to the same problem. This is because your application's classpath might be different and might not include the environment classpath. Check out your IDE's properties here. The problem is that CaptureDeviceManager cannot find the jmf.properties file because it is not there.
As you have found out correctly, you can copy the jmf.properties file from the JMF installation folder. It would contain the correct device list since JMF detects it during the install (Check it out just to make sure anyway).
If you want do device detection yourself, then create an empty jmf.properties file and put it somewhere in your classpath (it might throw a java.io.EOFException initially during execution but that's properly handled by the JMF classes). Then use the following code for detecting webcams...
import javax.media.*;
import java.util.*;
public static void main(String[] args) {
VFWAuto vfwObj = new VFWAuto();
Vector devices = CaptureDeviceManager.getDeviceList(null);
Enumeration deviceEnum = devices.elements();
System.out.println("Device count : " + devices.size());
while (deviceEnum.hasMoreElements()) {
CaptureDeviceInfo cdi = (CaptureDeviceInfo) deviceEnum.nextElement();
System.out.println("Device : " + cdi.getName());
}
}
The code for the VFWAuto class is given below. This is part of the JMStudio source code. You can get a good idea on how the devices are detected and recorded in the registry. Put both classes in the same package when you test. Disregard the main method in the VFWAuto class.
import com.sun.media.protocol.vfw.VFWCapture;
import java.util.*;
import javax.media.*;
public class VFWAuto {
public VFWAuto() {
Vector devices = (Vector) CaptureDeviceManager.getDeviceList(null).clone();
Enumeration enum = devices.elements();
while (enum.hasMoreElements()) {
CaptureDeviceInfo cdi = (CaptureDeviceInfo) enum.nextElement();
String name = cdi.getName();
if (name.startsWith("vfw:"))
CaptureDeviceManager.removeDevice(cdi);
}
int nDevices = 0;
for (int i = 0; i < 10; i++) {
String name = VFWCapture.capGetDriverDescriptionName(i);
if (name != null && name.length() > 1) {
System.err.println("Found device " + name);
System.err.println("Querying device. Please wait...");
com.sun.media.protocol.vfw.VFWSourceStream.autoDetect(i);
nDevices++;
}
}
}
public static void main(String [] args) {
VFWAuto a = new VFWAuto();
System.exit(0);
}
}
Assuming you are on a Windows platform and you have a working web-cam, then this code should detect the device and populate the jmf.properties file. On the next run you can also comment out the VFWAuto section and it's object references and you can see that CaptureDeviceManager reads from the jmf.properties file.
The VFWAuto class is part of jmf.jar. You can also see the DirectSoundAuto and JavaSoundAuto classes for detecting audio devices in the JMStudio sample source code. Try it out the same way as you did for VFWAuto.
My configuration was Windows 7 64 bit + JMF 2.1.1e windows performance pack + a web-cam.
I had the same issue and I solved by invoking flush() on my ObjectInputStream object.
According to the API documentation for ObjectInputStream's constructor:
The stream header containing the magic number and version number are read from the stream and verified. This method will block until the corresponding ObjectOutputStream has written and flushed the header.
This is a very important point to be aware of when trying to send objects in both directions over a socket because opening the streams in the wrong order will cause deadlock.
Consider for example what would happen if both client and server tried to construct an ObjectInputStream from a socket's input stream, prior to either constructing the corresponding ObjectOutputStream. The ObjectInputStream constructor on the client would block, waiting for the magic number and version number to arrive over the connection, while at the same time the ObjectInputStream constructor on the server side would also block for the same reason. Hence, deadlock.
Because of this, you should always make it a practice in your code to open the ObjectOutputStream and flush it first, before you open the ObjectInputStream. The ObjectOutputStream constructor will not block, and invoking flush() will force the magic number and version number to travel over the wire. If you follow this practice in both your client and server, you shouldn't have a problem with deadlock.
Credit goes to Tim Rohaly and his explanation here.
Before calling CaptureDeviceManager.getDeviceList(), the available devices must be loaded into the memory first.
You can do it manually by running JMFRegistry after installing JMF.
or do it programmatically with the help of the extension library FMJ (Free Media in Java). Here is the code:
import java.lang.reflect.Field;
import java.util.Vector;
import javax.media.*;
import javax.media.format.RGBFormat;
import net.sf.fmj.media.cdp.GlobalCaptureDevicePlugger;
public class FMJSandbox {
static {
System.setProperty("java.library.path", "D:/fmj-sf/native/win32-x86/");
try {
final Field sysPathsField = ClassLoader.class.getDeclaredField("sys_paths");
sysPathsField.setAccessible(true);
sysPathsField.set(null, null);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String args[]) {
GlobalCaptureDevicePlugger.addCaptureDevices();
Vector deviceInfo = CaptureDeviceManager.getDeviceList(new RGBFormat());
System.out.println(deviceInfo.size());
for (Object obj : deviceInfo ) {
System.out.println(obj);
}
}
}
Here is the output:
USB2.0 Camera : civil:\\?\usb#vid_5986&pid_02d3&mi_00#7&584a19f&0&0000#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\global
RGB, -1-bit, Masks=-1:-1:-1, PixelStride=-1, LineStride=-1
Related
I need the functionality like that of the rsync linux tool in my Java program. For that, I chose the rsync4j library.
Using their documentation, I wrote the following program:
import com.github.fracpete.processoutput4j.output.ConsoleOutputProcessOutput;
import com.github.fracpete.rsync4j.RSync;
public class MainClass {
public static void main(String [] args) {
System.out.println("Started");//check
RSync rsync = new RSync()
.source("/home/arth/DataSourceFolder/a.txt")
.destination("/home/arth/DataDestinationFolder/")
.recursive(true);
// or if you prefer using commandline options:
// rsync.setOptions(new String[]{"-r", "/one/place/", "/other/place/"});
CollectingProcessOutput output = null;
try {
System.out.println("Inside try");
output = rsync.execute();
System.out.println("End of try");
} catch (Exception e) {
e.printStackTrace();
}
System.out.println(output.getStdOut());
System.out.println("Exit code: " + output.getExitCode());
if (output.getExitCode() > 0)
System.err.println(output.getStdErr());
}
}
In the snippet, in out local machine, a file a.txt is copied from one location to another. This works perfectly. The file is successfully copied when I run it and here is the output:
Started
Inside try
End of try
Exit code: 0
But my need is to sync a local directory with a directory lying at a remote host/machine. When I tried to do it using a simple rsync command from a terminal using the following command
rsync remoteUserName#23.24.25.244:/home/beth/remoteFolder/a.png /home/arth/DataSourceFolder
it works like a charm. a.png IS copied to local machine at path specified, although a password of remote machine is asked first.
But the problem when I use the above Java program to do the same operation, by replacing line # 11 and 12 by:
.source("remoteUserName#23.24.25.244:/home/beth/remoteFolder/a.png")
.destination("/home/arth/DataDestinationFolder/")
the program gets stuck after printing Started in the console. Neither an exception is thrown nor does the program proceed.
The question is that how do I fix this problem?
(old post, I know, but here it goes...) The rsync4j library does not allow interaction. In your case, the underlying rysnc binary prompts for a password in the process that the Java library created, but never receives one.
Starting with release 3.2.3-7, you can supply an instance of the sshpass wrapper to feed in the password (see this comment for an example).
I want to use matlab function in java application. I create java package from my function by deploytool in matlab. Now, how can i use this package? Can only import the jar file created by deploytool in my java project and use its function?
After a lot of googling, I used this toturial but in the final step, i get error "could not load file".
Also i read about MatlabControl, but in this solution, we should have matlab environment in our system to java code running. But i will run my final app in systems that may not have matlab at all.
So i need a solution to run matlab function in java class even in absence of matlab environment.
Finally I solve my problem. the solution step by step is as follows:
write matlab function:
function y = makesqr(x)
y = magic(x);
Use deploytool in matlab and create java package.
3.create new java application in Eclipse and add main class. import javabuilde.jar and makesqr.jar:
import com.mathworks.toolbox.javabuilder.MWArray;
import com.mathworks.toolbox.javabuilder.MWClassID;
import com.mathworks.toolbox.javabuilder.MWNumericArray;
import makesqr.Class1;
and main.java:
public class main {
public static void main(String[] args) {
MWNumericArray n = null;
Object[] result = null;
Class1 theMagic = null;
try
{
n = new MWNumericArray(Double.valueOf(5),MWClassID.DOUBLE);
theMagic = new Class1();
result = theMagic.makesqr(1, n);
System.out.println(result[0]);
}
catch (Exception e)
{
System.out.println("Exception: " + e.toString());
}
finally
{
MWArray.disposeArray(n);
MWArray.disposeArray(result);
theMagic.dispose();
}
}
}
add javabuilder.jar and makesqr.jar to java build path of your project.
run it.
the Double.valueOf(3), define the input for our function and the output is as follows:
8 1 6
3 5 7
4 9 2
I didn't get properly your problem. Did you already compile the jar file from Matlab code and you are trying to use that, or you are at the last step of the tutorial?
If your answer is the latest case, most probably you forgot the "." before the class path.
From tutorial you linked:
You must be sure to place a dot (.) in the first position of the class path. If it not, you get a message stating that Java cannot load the class.
Also check if the matlab compiler path ("c:\Program Files\MATLAB\MATLAB Compiler Runtime\v82\toolbox\javabuilder\jar\javabuilder.jar" - in the tutorial) is correct for your system.
I am new to WEBMethods. I have been working on a Java service for a project. I really need to be able to write some code in regular Java for some quick testing of reading in a simple text expression with some regular expressions. Nothing at all that fancy with the Java part. But eclipse currently is set up for WEBMethods and I need to be in a regular Java mode for Eclipse (If there is such a thing). At home I have the standard eclipse version and have no trouble writting code. But at work I have WEBMethods installed in the Eclipse (Software AG Designer). I think that if I can write the code in regular Java then I can just copy and paste it into the WEBMethods Java services and set up the INPUT and OUTPUT variables and it should work. But currently I cannot find a way to just write Java code like I do from my home computer.
Question: How can I write just a regular Java program (classes, packages, ...etc...) with a machine with WEBMethods installed? Do I have to install another session of Eclipse on my hard drive? (I tried this a while back and there was an issue with having more than one session of Eclipse on the machine).
Java Web Services Code:
package DssAccessBackup.services.flow;
import com.wm.data.*;
import com.wm.util.Values;
import com.wm.app.b2b.server.Service;
import com.wm.app.b2b.server.ServiceException;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
public final class new_javaService_SVC
{
/**
* The primary method for the Java service
*
* #param pipeline
* The IData pipeline
* #throws ServiceException
*/
public static final void new_javaService(IData pipeline)
throws ServiceException {
// pipeline
IDataCursor pipelineCursor = pipeline.getCursor();
String inputFileName = IDataUtil.getString( pipelineCursor, "inputFileName" );
pipelineCursor.destroy();
// pipeline
IDataCursor pipelineCursor_1 = pipeline.getCursor();
IDataUtil.put( pipelineCursor_1, "fileName", "fileName" );
// outDoc
IData outDoc = IDataFactory.create();
IDataUtil.put( pipelineCursor_1, "outDoc", outDoc );
pipelineCursor_1.destroy();
String fileName = new String();
fileName = null;
try {
BufferedReader reader = new BufferedReader(new FileReader("C:\\Users\\itpr13266\\Desktop\\TestFile.txt"));
String line = null;
//Will read through the file until EOF
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
} catch (IOException e) {
System.out.println("Try-Catch Message - " + e.getMessage());
e.printStackTrace();
}
}
// --- <<IS-BEGIN-SHARED-SOURCE-AREA>> ---
// --- <<IS-END-SHARED-SOURCE-AREA>> ---
}
You don't need to install another Eclipse for Java development. WebMethods Designer (v9) comes with Java tooling. Just open the Java perspective and use it.
Besides that you should use the Service Development perspective, when developing WebMethods Java Services, because WM Designer handles Java services in a special way, which could make importing standard Java files difficult.
There is no problem running multiple instances of Eclipse at the same time as long as they point to different workspaces.
Normally you get a dialog to choose the workspace when Eclipse starts up. If not, check this answer on how to enable that dialog: https://stackoverflow.com/a/8616216/1599890
So if you download, unzip and set up Eclipse for Java development and point it to another workspace than Software AG Designer uses you should be good to go.
Greetings,
I would like to ask if there's a way to block website(s) from access on a computer(s) dynamically? I mean could this functionality be coded (on java native interface)?
Your response is highly appreciated.
Thanks,
Cyril H.
Yes, you can code a simple HTTP proxy service with Java:
http://www.java2s.com/Code/Java/Network-Protocol/Asimpleproxyserver.htm
Alternatively, there are plenty of existing proxy solutions out there might suit your needs out of the box:
http://www.roseindia.net/opensource/freeproxyservers.php
You would then configure the software/devices that access websites (e.g., your browser) to point to that proxy, so that all HTTP communication passed through it.
Your proxy could then restrict access to whatever URL(s) you wanted to, based on whatever logic you wanted to code up.
If you wanted to get really fancy/secure and require folks to use the proxy (and not to choose to bypass it), you could do that, but that's probably more than you need to, given your question.
You could append entries to your hosts file using the Files class, as shown in this post: How to append text to an existing file in Java?.
This works on all platforms (yes, all of them: including Windows, Mac, Linux, Android, and more), and blocks access for all browsers, without the need for a proxy or special browser extensions (which can be deleted in most cases).
Here is some simple code to start you off. Feel free to edit it to fit your needs:
public void blockSite(String url) {
// Note that this code only works in Java 7+,
// refer to the above link about appending files for more info
// Get OS name
String OS = System.getProperty("os.name").toLowerCase();
// Use OS name to find correct location of hosts file
String hostsFile = "";
if ((OS.indexOf("win") >= 0)) {
// Doesn't work before Windows 2000
hostsFile = "C:\\Windows\\System32\\drivers\\etc\\hosts";
} else if ((OS.indexOf("mac") >= 0)) {
// Doesn't work before OS X 10.2
hostsFile = "etc/hosts";
} else if ((OS.indexOf("nux") >= 0)) {
hostsFile = "/etc/hosts";
} else {
// Handle error when platform is not Windows, Mac, or Linux
System.err.println("Sorry, but your OS doesn't support blocking.");
System.exit(0);
}
// Actually block site
Files.write(Paths.get(hostsFile),
("127.0.0.1 " + url).getBytes(),
StandardOpenOption.APPEND);
}
Imports for above method:
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
Sample usage:
blockSite("www.example.com");
Note:
This needs to be run as an administrator (Windows) or using sudo (Mac, Linux).
This might not work for some platforms, as it was only tested on Ubuntu Linux.
P.S. If you're making parental control software, you should also look into blocking programs. Not all things you would want to block are on the Internet. Here is some simple code for that:
/**
Blocks programs.
#param programs - The array of process names.
#param timeout - The time between blocks, in milliseconds.
This parameter should not be set below 100, to avoid slowdown.
#author https://stackoverflow.com/users/5905216/h-a-sanger
*/
public void blockPrograms(int timeout, String...programs) throws IOException {
// Get OS name
String OS = System.getProperty("os.name").toLowerCase();
// Identify correct blocking command for OS
String command = "";
if ((OS.indexOf("win") >= 0)) {
command = "taskkill /f /im ";
} else if ((OS.indexOf("mac") >= 0) || (OS.indexOf("nux") >= 0)) {
command = "killall ";
} else {
// Handle error when platform is not Windows, Mac, or Linux
System.err.println("Sorry, but your OS doesn't support blocking.");
System.exit(0);
}
// Start blocking!
while(true) {
// Cycle through programs list
for(int i = 0; i < programs.length; i++) {
// Block program
Runtime.getRuntime().exec(command + programs[i]);
}
// Timeout
try { Thread.sleep(timeout); } catch(InterruptedException e) {}
}
}
Imports for above code:
import java.io.IOException;
Sample usage:
blockPrograms(100, "chrome", "firefox");
Again, let me note this was only tested on Ubuntu Linux.
Java is the key here. I need to be able to delete files but users expect to be able to "undelete" from the recycle bin. As far as I can tell this isn't possible. Anyone know otherwise?
Ten years later, with Java 9, finally there is a builtin way to move files to the Trash Bin
java.awt.Desktop.moveToTrash(java.io.File):
public boolean moveToTrash(File file)
Moves the specified file to the trash.
Parameters:
file - the file
Returns:
returns true if successfully moved the file to the trash.
The availability of this feature for the underlying platform can be tested with Desktop.isSupported(Desktop.Action.MOVE_TO_TRASH).
For various reasons Windows has no concept of a folder that simply corresponds to the Recycle Bin.
The correct way is to use JNI to invoke the Windows SHFileOperation API, setting the FO_DELETE flag in the SHFILEOPSTRUCT structure.
SHFileOperation documention
Java example for copying a file using SHFileOperation (the Recycle Bin link in the same article doesn't work)
Java 9 has new method but in my case I am restricted to Java 8.
I found Java Native Access Platform that has hasTrash() and moveToTrash() method. I tested it on Win 10 and Mac OS (Worked) for me.
static boolean moveToTrash(String filePath) {
File file = new File(filePath);
FileUtils fileUtils = FileUtils.getInstance();
if (fileUtils.hasTrash()) {
try {
fileUtils.moveToTrash(new File[] { file });
return true;
} catch (IOException e) {
e.printStackTrace();
return false;
}
} else {
System.out.println("No Trash");
return false;
}
}
Maven Repository
https://mvnrepository.com/artifact/net.java.dev.jna/jna-platform/5.1.0
Don't confuse It is Java Native Access Platform not Java Native Access
See the fileutil incubator project (part of the Java Desktop Integration Components project):
This incubator project is created to host those file utility functionalities, most of which are extensions to the java.io.File class in J2SE. There are frequent requests from Java developers for such features like: sending a file to trash bin, checking free disk space, accessing file attributes etc. This project addresses such frequently requested APIs.
Note, this should work not only on Windows, but on other platforms (Linux, Mac OS X) as well.
My 3 cents - use cmd util Recycle.exe with -f to force recycle (no prompt). Works perfectly.
public class Trash {
public void moveToTrash(File ... file) throws IOException {
moveToTrash(false, file);
}
public void promptMoveToTrash(File ... file) throws IOException {
moveToTrash(true, file);
}
private void moveToTrash(boolean withPrompt, File ... file) throws IOException {
String fileList = Stream.of(file).map(File::getAbsolutePath).reduce((f1, f2)->f1+" "+f2).orElse("");
Runtime.getRuntime().exec("Recycle.exe "+(withPrompt ? "" : "-f ")+fileList);
}
}
In JNA platform, the FileUtils doesn't use Win32 API. You should prefer W32FileUtils which supports Undo (restore the file from recycle bin).
Edit: as of the current version of JNA Platform (5.7.0), with FileUtils.getInstance(), this statement has become incorrect, and FileUtils will use the Win32 API.