Exception in thread “main” java.lang.UnsatisfiedLinkError 3

Question

Hi guys i have tried all the solutions like java -Djava.library.path=. demo adding the dll path to PATH java -Djava.library.path=c:\\JNI\\demo.dll demo

But still the above error.

Here is my java code..

class demo
{
    public native void printline();
    public static void main(String[]args)
    {
        new demo().printline();
    }
}

Here is my c code...

#include<stdio.h>
#include<jni.h>

#include "demo.h"

JNIEXPORT void JNICALL Java_demo_printline(JNIEnv *a, jobject b)
{
    printf("Hello wrold!!!");
    return;
}

Steps for compiling and running,

1. javac demo.java
2. javah demo
3. gcc -c -I"c:\\jdk1.7.0_55\\include" -I"c:\\jdk1.7.0_55\\include\\win32" demo.c
4. gcc -Wl,--add-stdcall-alias -shared -o demo.dll demo.c
5. java -Djava.library.path=c:\\JNI\\demo.dll demo

Am i going wrong somewhere?

can someone please help me out,.

Answer 1

Try Run-Time Loading of the dll file within the java code in a static block like:

static
{
System.loadLibrary("demo");
}

should give you the output.

Moreover make sure that dll file generated is x32 or x64 according to the gcc compiler in use.

Answer 2

looking for "JNI hello world" (or many other terms, possibly), would have given you the answer.

for example:

http://www3.ntu.edu.sg/home/ehchua/programming/java/JavaNativeInterface.html

• you need to load the library inside your java code
• you need to specify the path to the directory of the library, not to the library itsself, in java.library.path