Dll-in-jar access by java2/1.2 applet

Given the new security mechanisms of Java2/1.2, is it possible for an applet loaded from the network to access a dll in a jar?
TIA,
Reggie

Java Web Start can access and load native librarys (dll's) but only if the application is signed and requesting <all-permissions> - see the developers guide: http://java.sun.com/products/javawebstart/1.2/docs/developersguide.html#jnlp
and the section on the Nativelib element.

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Hi,
I am getting "Object doesn't support this property or method" error
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Regards,
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WHY can't I access my database from an applet???????????

The security code won't let my applet access its own database (from its own server)..
I'm using getDocumentBase()
to try and tell it that it is my own damn file..
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The simple answer to your question is: Because of security concerns.
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Hi, Trying to log in with my user id and password at iocbc but was not able to access. Problem message shown : Applet not initialised or may not be supported. Please refresh the page or check the browser setting Anyone can advise? or i need to download?

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You need to install Java for your Mac OS version, and/or make sure it's enabled in the Java Preferences application and your browser's preferences.

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import java.applet.*;
import java.awl.*;
import java.sql.*;
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Connection con;
Statement stmt;
String name="drvijay";
String phoneno="9842088860";
public void init(){}
pubilc void stop(){}
public void destroy(){}
public void start()
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I have a jtabbedpane that can open multiple windows and in each window the component is a different instatiation of this one applet. I was just wondering if there is any way that I could access the methods of that applet w/in that tabbed pane position. So far I've tried making a copy of the component(the applet), and then access the method of the copy, and then setting the copy to be the component of that tabbed pane, but that just seemed a little resource heavy.
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I'm not sure the following problem is related to this forum but...
I have problem to load native code (DLL) by running executabe JAR file(created by JBuilder 9).
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When run the EXE an error says "JVM cannot load the DLL" in java library path.
I have tried without succes:
1. Loading dll in main function: [System.load() & System.loadlibrary()].
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How to pass a struct to a DLL function and accessing it in another VI

Hi friends,
                   I am new to labview. I need to create a demo program in labview ,for displaying image from our own image capturing system. We have a DLL ( build in VC++) containing functions for capturing image from our system. Now I need to create a VI library for some of functions in DLL and Create a Demo program using those created subvi library . I used "Call Function node" and created some of subvi's.
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__declspec(dllexport) int __stdcall Initialize( unsigned char *imagebuffer,struct config *Configuration);
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struct config
double                val1[3];
unsigned short   val2;
bool                    val3;
bool                    val4[3];
unsigned char    val5;
unsigned char   val6[3];
bool                    val7[26];
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aajjf.
Message Edited by aajjf on 04-19-2007 05:34 AM

aajjf wrote:
Hi friends,
                   I am new to labview. I need to create a demo program in labview ,for displaying image from our own image capturing system. We have a DLL ( build in VC++) containing functions for capturing image from our system. Now I need to create a VI library for some of functions in DLL and Create a Demo program using those created subvi library . I used "Call Function node" and created some of subvi's.
Some of our DLL functions need to pass struct pointers. Our function prototype will be similar to the following function.
__declspec(dllexport) int __stdcall Initialize( unsigned char *imagebuffer,struct config *Configuration);
The passed struct is similar to
struct config
double                val1[3];
unsigned short   val2;
bool                    val3;
bool                    val4[3];
unsigned char    val5;
unsigned char   val6[3];
bool                    val7[26];
For passing "unsigned char *imagebuffer" I initialized array with "Numeric constant " and set the size of the array and send to the function.
The problem here is, I used this array in one of the subvi.
How can I use the returned imagebuffer array in my main demo program. How to connect the image array to subvi "Connecter Pane"
And which control can I use to display the image. The image data I get is form of 1-D Array .
The second problem is,
   For passing the structure, I used "Bundle " and filled the bundle with all the datatypes as in my struct and passed to the function. Is it correct ? How to access this bundle after returned from function in another Vi. ie.) How to connect this bundle to the connter pane ?
Thanks for your valuable suggestions.
aajjf.
Message Edited by aajjf on 04-19-2007 05:34 AM
You say nothing about how your cluster looks but I'm afraid you did the standard error here and placed arrays in it. That is not what the C structure is representing for several reasons.
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Last but not least you can end up with alignment issues. Elements in structures are aligned by every C compiler to a certain value. This value can be defined by the programmer in the project settings or for Visual C through #pragma pack() statements in the C code. The alignment rule says that an variable is aligned to the smaller of the two values that are either a multiple of the variable element size or the alignment setting. Most 32bit code nowadays uses 8 bit default alignment but LabVIEW always uses 1 byte. In your case there is nothing to observe since the large variables are at the beginning. Otherwise you might have had to insert filler elements in the LabVIEW cluster.
One last thing bool is a C++ type only. Its size is 1 byte and incidentially this is the same LabVIEW uses for Booleans.
Rolf Kalbermatter
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

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Originally Posted by xirphoid
I have been able to reproduce this error whenever we have Internet Explorer 8 installed on a Windows XP SP3 machine, running GroupWise 7.0.4.
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New Mail -> Enter user in "To:" Field -> Click on "Subject Line" -> Go Back to "To:" field, and Right-Click on User, and select "Details".
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HI,
I used the below jnlp file
<?xml version="1.0" encoding="UTF-8"?>
<jnlp href="java2d.jnlp">
<information>
<title>Java2D Demo</title>
<vendor>My Company, Inc.</vendor>
<offline-allowed />
</information>
<resources>
<j2se version="1.4+" href="http://java.sun.com/products/autodl/j2se" />
<jar href="myapplet.jar" main="true" />
<nativelib href="mydlls.jar"/>
</resources>
<applet-desc name="MyFileAccess" main-class="com.applet.MyFileAccess" width="710" height="540">
</applet-desc>
</jnlp>
mydlls.jar contain the jniwrap.dll file. i have copied the jniwrap.lic to META-INF folder of myaaplet.jar file.
The dll is recognized by JVM and also license verification is success.
But got the below error still, i have the b.class in the applet jar itself.
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     at java.lang.ClassLoader.defineClass(Unknown Source)
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     at java.net.URLClassLoader.defineClass(Unknown Source)
     at sun.reflect.GeneratedMethodAccessor3.invoke(Unknown Source)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
     at java.lang.reflect.Method.invoke(Unknown Source)
     at sun.plugin2.applet.Plugin2ClassLoader.defineClassHelper(Unknown Source)
     at sun.plugin2.applet.Plugin2ClassLoader.access$400(Unknown Source)
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     at java.lang.ClassLoader.loadClass(Unknown Source)
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     at com.jniwrapper.win32.Handle.<init>(SourceFile:17)
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     at com.applet.MyFileAccess.addIE8Key(MyFileAccess.java:1096)
     at com.applet.MyFileAccess.init(MyFileAccess.java:3794)
     at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
     at java.lang.Thread.run(Unknown Source)
copied the class files to mydlls.jar also, same exception. Please suggest.
Edited by: user13722950 on Feb 22, 2011 12:35 AM

Dynamically Loading .jar into the AppletClassLoader of Signed Applet

First of all, I thank you for reading this post. I will do everything I can to be concise, as I know you have things to do. If you're really busy, I summarize my question at the bottom of this post.
My goal:
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I have gotten all the way to step 5!!! It was amazing!
But now I'm stuck on step 5. I can download the .jar files, read them, even decode the classes!
As evidence, I had it print out random Methods using reflection on the created classes:
public net.java.games.input.Component$Identifier net.java.games.input.AbstractComponent.getIdentifier()
public final void net.java.games.input.AbstractController.setEventQueueSize(int)
public java.lang.String net.java.games.input.Component$Identifier.toString()
public final native void java.lang.Object.wait(long) throws java.lang.InterruptedException
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Here is how I am loading the classes from the jar and attempting to shove them on the appletclassloader:
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try {
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} catch (MalformedURLException e2) {
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final JarFile ajar = new JarFile(url);
... we iterate over the elements (trust me, this part works)
String name = entry.getName();
if (name.endsWith(".class")) {
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public class AllPermissionsClassLoader extends URLClassLoader {
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}so, my assumption here is that if I create a new AllPermissionsClassLoader and then call loadClass, the loaded class (because it does return a valid Class object) is usable globally across my applet. If this is not true, how should I else be doing this? Thank you for Any advice you could offer!

I know it's two years ago but the OP's approach seems pointless to me.
4.) Applet downloads the .jar files that we stripped so that the applet was smaller, one by oneWhy? Just name the JAR files in the CLASSPATH attribute of the <applet> tag. Then what you describe in (5) and (6) happens automatically on demand.
protected PermissionCollection getPermissions (CodeSource codesource) {Who does he think is going to call that?

Dll-in-jar access by java2/1.2 applet

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