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java rmi simple project classNotFoundException binding registry

Ok, I'm sure this should be pretty easy, but I'm fairly new to Java (I'm more a .NET boy :P) and after following every single recommendation I found here to no success, I think it's time to step back and ask.
I'm trying to start a simple rmi project with a client, a server and a common project where common interfaces are defined. I've just implemented my server code, and when I try to run it to check if everything is fine, I get struck on a java.lang.ClassNotFoundException.
After following several answers on similar issues, I'm fair sure that my problem comes from rmiregistry running on a different location than my project.
I use following code to set registry codebase:
public class Utils {
public static final String CODEBASE = "java.rmi.server.codebase";
public static void setCodeBase(Class<?> c) {
String ruta = c.getProtectionDomain().getCodeSource().getLocation().toString();
String path = System.getProperty(CODEBASE);
if (path != null && !path.isEmpty()) {
ruta = path + " " + ruta;
}
System.setProperty(CODEBASE, ruta);
}
}
Then, I try to start my server code with this main class:
public class MainRegulador {
public static void main(String[] args) throws AccessException, RemoteException, NotBoundException {
Utils.setCodeBase(IRegulador.class);
Registry registro = null;
Remote proxy = null;
try {
Regulador myReg = new Regulador();
proxy = UnicastRemoteObject.exportObject(myReg, 36510);
registro = LocateRegistry.getRegistry();
registro.rebind("Distribuidor", proxy); //this is the line where exception is thrown
System.out.println("El Regulador está corriendo. Pulse ENTER para finalizar el proceso.");
System.in.read();
} catch(Exception ex) {
System.out.println("No se ha logrado inicializar el Registrador");
System.out.println(ex.getMessage());
} finally {
if (registro != null && proxy != null) {
registro.unbind("Distribuidor");
UnicastRemoteObject.unexportObject(proxy, true);
}
}
}
}
But when I run it, always get a java.lang.ClassNotFoundException at IRegulador interface.
Now the fun part:
I've printed to console java.rmi.server.codebase value, and it's pointing to bin folder of project where IRegulador interface is defined. (file:/F:/Practicas%20y%20dem%c3%a1s/Sistemas%20Distribuidos/common/bin/)
Obviously, that project is also set in the classpath of server project
(Regulador)
Workspace and rmiregistry are on different disks
Despite all, it doesn't seem a global classpath problem, as Utils class is on the same project as IRegulador interface, and it runs before the exception is thrown (as java.rmi.server.codebase is correctly set).
I've tried to set the classpath of rmiregistry before calling it (although it is directly discouraged on some answers), but nothing changed.
I've also tried to start rmiregistry.exe from Regulador project bin folder, but also seemed to don't change anything.
Coming from a .NET background, I've always found these classpath issues confusing, and this one is starting to consume much more time than I suspect it deserves. I'm in desperate need of help.
UPDATE: I'm starting to think that the problem is within the url it's passed to the codebase from IRegulador.class. If I paste it into windows explorer, the SO is unable to locate it, so I supose that it's being built with some structure problem that prevents the registry to reach the route:
file:/F:/Practicas%20y%20dem%c3%a1s/Sistemas%20Distribuidos/common/bin/
UPDATE2: I thought path route could be too complex, so I decided to simplify it and strip it from any non-straight character. Now codebase value is
file:/F:/Practicas/SD/common/bin/
However the problem persists, I don't know why rmiregistry is unable to reach that folder.
Then I decided to move the whole project to the same disk where rmiregistry is executed, and see if it changes anything. But nothing changed, same problem.

Ok, finally I got it working...
I've just copied rmiregistry.exe into the common/bin folder and launch it directly from there (previously just had called from there).
This seems to fix the problem with the routes (actually it makes the route available to the registry as it's on the same folder, probably all my codebase writting code is superflous now).

Run matlab function in java class in absence of matlab environment

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.

Access parameters from custom URI scheme in Java application on OS X

I've successfully added a custom URI scheme in info.plist on OS X so my Java 1.7 based application (written in Netbeans) is launched whenever the user enters "myApp:SomeParameter" in their browser:
<key>CFBundleURLTypes</key>
<array>
<dict>
<key>CFBundleURLName</key>
<string>My App</string>
<key>CFBundleURLSchemes</key>
<array>
<string>myApp</string>
</array>
</dict>
</array>
I have also successfully added the corresponding registry entry for the application if installed on a Windows machine. The problem is that on the Windows platform I can easily pass on parameters (in the above case I want "SomeParameter" from the entered uri "myApp:SomeParameter"). It is simply passed on to the application main method as regular parameters, but this is not the case on OS X. I have done some research and tried this solution but it requires some Cocoa libraries and causes issues when compiled and run on Windows.
EDIT: I have tried to track down a version of AppleJavaExtensions that contains the com.apple.eawt.Application.setOpenURIHandler() but I've only found version 1.4 where it's missing. Any idea why?
Is there another way to pass parameters from a custom URI scheme to a cross platform Java application running on Mac / OS X?
EDIT 2: Please see accepted answer below, but as a side note: we successfully experimented with a possible workaround using AppleScript as a middle-tier. The script in this article can be simplified to receive the full URL with parameters, and then invoke your Java based application with the query string as normal command line parameters.

It looks like you're on the right track. Your Info.plist looks correct. You don't need to create any custom native Cocoa code, just use setOpenURIHandler(). For example:
public class AppleMenus implements com.apple.eawt.OpenURIHandler {
private MyApp myApp;
public AppleMenus(MyApp myApp) {
this.myApp = myApp;
final com.apple.eawt.Application app = com.apple.eawt.Application.getApplication();
app.setOpenURIHandler(this);
}
#Override
public void openURI(final com.apple.eawt.AppEvent.OpenURIEvent oue) {
myApp.openCustomURL(oue.getURI());
}
}
The only reason you would need AppleJavaExtensions is if you are trying to compile this code on a non-Apple environment, such as Windows. Windows won't know what OpenURIHandler is, so you will get a compile error there. AppleJavaExtensions just provides that necessary API without implementation, just for the purposes of being able to compile in these other environments.
Here, is the official latest (and probably last) version: https://developer.apple.com/legacy/library/samplecode/AppleJavaExtensions/Introduction/Intro.html
Note that your URI handler will be called in the currently running instance of you app or will first create a new instance of your app then get called. The OpenURIEvent will contain the entire URI message you send.

The following (for Java 9) will work cross platform (Windows and macOS has been tested):
import java.awt.*;
import java.awt.desktop.OpenURIEvent;
import java.awt.desktop.OpenURIHandler;
import java.net.URI;
import java.net.URISyntaxException;
public class UriLaunchedApp {
public static void main(String[] args) throws URISyntaxException {
try {
Desktop.getDesktop().setOpenURIHandler(new OpenURIHandler() {
#Override
public void openURI(OpenURIEvent e) {
System.out.println("We are maybe on macOS...");
processUri(e.getURI());
}
});
} catch (UnsupportedOperationException e) {
System.out.println("We are maybe on Windows...");
processUri(new URI(args[0]));
}
}
private static void processUri(URI uri) {
System.out.println("Do something with " + uri);
}
}
See too https://docs.oracle.com/javase/9/docs/api/java/awt/Desktop.html#setOpenURIHandler-java.awt.desktop.OpenURIHandler-.

Java: CaptureDeviceManager#getDeviceList() is empty?

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

What is causing this Java "Cannot find symbol" error?

I'm modifying inherited code and keep getting a weird "cannot find symbol" error which is throwing me off.
//======= Error =========
Compiling 1 source file to /Users/Inprimus/Projects/Workspace/Soft/build/web/WEB-INF/classes
/Users/Inprimus/Projects/Workspace/Soft/WebContent/WEB-INF/classes/fr/service/CarPeer.java:49: cannot find symbol
symbol : method addCarToCompany(java.lang.Long,fr.model.company.Car)
location: class fr.dao.CompanyDAO
cmpDAO.addCarToCompany(idCompany,car);
^
1 error
Car peer:
package fr.service;
import fr.model.company.Car;
import fr.dao.CompanyDAO;
import fr.dao.CarDao;
public class CarPeer {
private static CarDao carDAO= new CarDao();
private static CompanyDAO cmpDAO = new CompanyDAO();
public static void storeCar(Long idCompany, Car car) throws UserServiceException, Exception {
try {
cmpDAO.addCarToCompany(idCompany,car);
System.out.println("Car stored : "+car.toString()+" in "+idCompany);
carDAO.storeCar(car);
} catch(DAOException ex) {
throw new UserServiceException(ex.getMessage(), ex);
}
}
}
CompanyDao:
package fr.dao;
import fr.model.accounting.Cost;
import fr.model.company.Car;
public class CompanyDAO extends GenericDAO<Company> {
private enum ChildType {
COST{
public void addChildToCompany(Company company, Object child) {
company.addCost((Cost)child);
}
},
CAR{
public void addChildToCompany(Company company, Object child) {
company.addCar((Car)child);
}
};
public abstract void addChildToCompany(Company company, Object child);
}
private void addChildToCompany(Long idCompany, Object child, ChildType type) throws NotFoundDAOException, AlreadyExistDAOException, Exception {
try {
// Begin unit of work
Session session = HibernateUtil.getSessionFactory().getCurrentSession();
session.beginTransaction();
Company company = (Company) session.load(Company.class, idCompany);
type.addChildToCompany(company, child);
session.flush();
// End unit of work
session.getTransaction().commit();
} catch (ObjectNotFoundException ex) {
HibernateUtil.getSessionFactory().getCurrentSession().getTransaction().rollback();
throw new NotFoundDAOException("Identified object " + idCompany
+ " doesn't exist in database", ex);
} catch (ConstraintViolationException ex) {
HibernateUtil.getSessionFactory().getCurrentSession().getTransaction().rollback();
throw new AlreadyExistDAOException("The new identity already exsits in database", ex);
} catch (Exception ex) {
ex.printStackTrace();
HibernateUtil.getSessionFactory().getCurrentSession().getTransaction().rollback();
throw new Exception(ex);
}
}
public CompanyDAO() {
super(Company.class);
}
public void addCarToCompany(Long idCompany, Car car) throws NotFoundDAOException, AlreadyExistDAOException, Exception {
addChildToCompany(idCompany, car, ChildType.CAR);
}
}
I have triple checked but can't find anything wrong with the code thus far. I am building it in Netbeans 7.0.1.I should mention that I get this error when I build, but I can run the web app with no issues whatsoever (yet). But I am worried this may come back to bite in the behind.
I just noticed in the file tree that above the CompanyDAO classes are similarly named files bearing the format: CompanyDAO$ChildType#.class (# corresponds to a number) I'm guessing it hasn't re-compiled the class to generate the extra child Type I added. How can I effect this?

Most likely you're using a previously compiled class file ( which didn't have the method ) in your classpath and the system is trying to use that instead of your current source code.
Otherwise, clean up your workspace, do not depend on existing compilations and try again. This has happened to me in the past.

I keep having the same problem (though I don't know whether it's for the same reason). For me, the only thing that works (apart from ditching this "robust" IDE) is to delete the cache. On windows, it's located in %UserProfile%\.netbeans\7.0\var\cache. I suppose on *nix, it could be under ~/.netbeans/7.0/var/cache. You have to exit NetBeans first, delete the cache, then start NetBeans again.

Is CompanyDao being compiled and available on the classpath before CarPeer?

Clean and build your project. If that doesn't work, then restart Netbeans. Sometimes Netbeans gives weird errors and a full restart of Netbeans and/or computer just seems to fix these unexplainable issues.

This could be the issue because the current netbeans instance that you are running is making use of the previously build up cache during its initialization. So, in order to clear the netbeans cache you can perform any of these two steps mentioned below.
APPROACH 1
1. right click on your project name in netbeans in the projects tab.
2. click on the clean and build option.
3. The cache has been cleared.
APPROACH 2
1. Click "windows key + R" and type "%UserProfile%/appdata/local/netbeans".
2. Navigate to the cache folder and then to the folder with name specifying the netbeans version.
3. Close the Netbeans and Delete all the files present in the folder.
4. Restart the netbeans and now you will be able to see the class name.
If any of these methods did not work then it might be the case that your classpath is not correct.

When using Netbeans 7.2+ do the following:
Close all tabs and exit Netbeans;
Remove cache directory: ~/.cache/netbeans/VERSION. Where VERSION is the Netbeans version, i.e. 7.3.1
Restart Netbeans and "Clean & Build"
Also see How to clear the cache in NetBeans
UPDATE (jan 2021)
Still works # Netbeans 12.2.
When Netbeans is installed with snap, the directory to delete / clean is: ~/snap/netbeans/common/cache