Load DLL library in my Applet

Question

When I try to run my applet on the server, it never seems to go out the first step, that is, loading libraries, and when I try to run on localhost, works perfectly

CODE

private final static String DEFAULT_DOWNLOAD_PATH = "http://colorfulwolf.com/dev/cam/";

private final static String VERSION_ID = "1.0.0";

// note that this list is windows-specific, so this is not a generic
// solution that works on all OSes
private final static String[] LIBS = { "cv210.dll", "cvaux210.dll",
        "cxcore210.dll", "cxts210.dll", "highgui210.dll", "ml210.dll" };

private final static String LIB_ARCHIVE = "opencv21.zip";

public void loadWebcam() {
        loadingScreen.setMaxProgress(7);
        loadingScreen.setProgress(1, "Loading Librarys..");
        String tmpDir = System.getProperty("java.io.tmpdir");

        File faPath = new File(tmpDir + File.separator + "WebcamApplet_"
                + VERSION_ID.replaceAll("\\.", "-"));
        System.out.println(faPath);     
        System.setProperty("jna.library.path", faPath.getAbsolutePath());

        String downloadPath = this.getParameter("dll_path");
        if (downloadPath == null)
            downloadPath = DEFAULT_DOWNLOAD_PATH;

        try {
            prepareLibraries(faPath, downloadPath);
        } catch (Exception e) {
            e.printStackTrace();
            loadingScreen.setProgress(3, "Erro: " + e.getMessage());
            return;
        }
}


    private void prepareLibraries(File localPath, String downloadPath)
            throws Exception {
        if (localPath.exists()) {
            boolean libMissing = false;
            for (String lib : LIBS) {
                File libFile = new File(localPath.getAbsolutePath()
                        + File.separator + lib);
                if (!libFile.exists()) {
                    libMissing = true;
                    break;
                }
            }

            if (!libMissing)
                return; // We don't have to download
        }

        if (!localPath.exists() && !localPath.mkdirs()) // Error fatal!
            throw new Exception("Can't create the path: " + localPath);

        loadingScreen.setProgress(2, "Downloading library...");
        File file = new File(localPath.getAbsolutePath() + File.separator
                + LIB_ARCHIVE);
        String link = downloadPath + LIB_ARCHIVE;
        download(link, file);

        ZipFile zipFile = new ZipFile(file);
        Enumeration<? extends ZipEntry> entries = zipFile.entries();

        loadingScreen.setProgress(3, "Installing librarys..");
        while (entries.hasMoreElements()) {
            ZipEntry entry = entries.nextElement();
            if (entry.isDirectory())
                continue;

            File tar = new File(localPath.getAbsolutePath() + File.separator
                    + entry.getName());
            InputStream is = zipFile.getInputStream(entry);
            OutputStream os = new FileOutputStream(tar);
            copyStream(is, os);
            os.flush();
            os.close();
            is.close();
        }
        zipFile.close();

        file.delete();
        if (file.exists())
            file.deleteOnExit();
    }

I put the jar files on the server in a visible HTTP path

<applet code="com.colorfulwolf.webcamapplet.WebcamApplet"        
    archive="http://www.netimoveis.com/teste.jar, http://www.netimoveis.com/core.jar, http://www.netimoveis.com/javacv.jar, http://www.netimoveis.com/javase.jar, http://www.netimoveis.com/jna.jar, http://www.netimoveis.com/customizer.jar, http://www.netimoveis.com/jmf.jar, http://www.netimoveis.com/meidaplayer.jar, http://www.netimoveis.com/multiplayer.jar, http://www.netimoveis.com/sound.jar"
    height="550" width="550">
</applet>

Why when I try to run the applet on the server, it does not leave the first step?

@UPDATE

I found the line where the code don't move to the next line of code. String tmpDir = System.getProperty("java.io.tmpdir"); this line is where my code stop and still just in this line. Java is currently installed in server.

Finsen

What errors are you getting? To do this from an applet within a browser it needs to be signed and run privileged. See here: https://mcmap.net/q/25141/-calling-a-dll-from-an-applet-via-jni/416627 – Workday

This is a problem. Without error when I tryied to run on server, but the applet still just in my first step. I signed the jar. – Finsen

the line where the code doesn't move is a new thing to me :P If your applet throws an Exception, you have to paste the stack trace. System.getProperty() can throw a SecurityException a NPE or a IllegalArgumentException as you can see – Dacy

Don't throw an Exception, in localhost works fine, but in the server, still processing this lines forever. – Finsen

I have 4 package in my project com.colorfulwolf.webcamapplet, com.colorfulwolf.webcamapplet.gui, com.google.zxing, com.google.zxing.client.j2se. My applet runs in a classe that are in my com.colorfulwolf.webcamapplet package. I need put the another packages in my code attribute in <applet> tag? – Finsen

What does it mean process this line forever? Are you stating the the thread blocks at System.getProperty()? How did you come to such a conclusion? It'd be a very strange thing indeed – Dacy

I put a JOptionPane after this line and didn't pass, and didin't pass in a catch statement. – Finsen

In another Thread I saw that it can probably be a ClassNotFound issue. How can I tell to the server how to find the class path of a specific package/class ? In Eclipse, it is done transparently when I add DSJ jar library under Referenced Libraries build tree – Finsen