Not returning from the native code

Question

Hi,
I am trying to access the native code using java applet. My java code seems to load the DLL(created using the VC++ 6.0) properly. Then when i call the native method called crypto, it does not seem to return from the nayive code . I am signing the applet and putting it a signed jar .Any suggestion is appreciated. I mite be wrong in the design too ...pleas ehelp. I am pasting the java code and the C code.
cryptoJNI.java
import java.awt.*;
import java.io.*;
import java.lang.*;
import java.applet.*;
public class cryptoJNI extends Applet {
     String uname=null;
     String b=null,ret=null;
     String a=null;
public void init(){
          System.out.println("in init");
     public void dll_load(){
          b="before dll";
          System.loadLibrary("Msgimpl");
          a="after dll load";
     private native String crypto(String store);
public void paint(Graphics g) {
          g.setColor(Color.blue);
          g.setColor(Color.magenta);
          load_dll();
          g.drawString(b, 5, 5);
          g.drawString(a, 15, 15);
          g.drawString("first call const", 25, 25);
          cryptoJNI app = new cryptoJNI();
          ret=app.crypto("My");
g.drawString(ret, 75, 75);
          g.drawString("Signed 11", 120, 80);
          stop();
CryptoJNI.c
#define WIN32WINNT 0x0400
#include <windows.h>
#include <jni.h>
#include <wincrypt.h>
#define MY_ENCODING_TYPE (PKCS_7_ASN_ENCODING | X509_ASN_ENCODING)
#include "cryptoJNI.h"
BOOL APIENTRY DllMain(HANDLE hModule,
DWORD dwReason, void** lpReserved) {
return TRUE;
JNIEXPORT void JNICALL
Java_CryptoJNI_crypto(JNIEnv * jEnv,jobject obj,jstring jstore) {
//     char               name[256];
     const char *msg;
     msg = (*jEnv)->GetStringUTFChars(jEnv, jstore,0);
     //printf("Before context\n");
     //(*jEnv)->ReleaseStringUTFChars(jEnv, jstore,msg);
     return (*jEnv)->NewStringUTF(jEnv, msg);
In my applet, i have some debugging statements that helps me verify that the Msgimpl.dll loads properly. When i invoke the app.crypto() it just "hangs". Please help
Thanks,
Vivek

Answer 1

Hi,
This is the exception that i am getting?? my cryptoJNIImp.c is is in the same directory as the my java file,c:\vivek work\signedcode. and i have added this to my path env variable...If u see the output, it executes the init() and then loads the Msgimpl.dll. So its got nothing do with loading a DLL. Any pointers on this..
in init
before loading dll
After loading dll
java.lang.UnsatisfiedLinkError: crypto
at cryptoJNI.crypto(Native Method)
at cryptoJNI.paint(cryptoJNI.java:65)
at sun.awt.RepaintArea.paint(Unknown Source)
at sun.awt.windows.WComponentPeer.handleEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)