An old and difficult problem about "UnsatisfiedLinkError"

Question

Hi dear all,
I have been struck with the problem about "UnsatisfiedLinkError". I have a c++ class HelloWorld with a method hello(), and I want to call it from within a java class. In fact, I have succeeded in calling it on the windows platform. But when I transfer it to linux, the error "UnsatisfiedLinkError" comes out. I have tried to take the measures as Forum has suggested, but it failed.
The source code is very simple to demonstrate JNI.
"HelloWorld.h"
#ifndef INCLUDEDHELLOWORLD_H
#define INCLUDEDHELLOWORLD_H
class HelloWorld
public:
void hello();
#endif
"HelloWorld.cpp"
#include <iostream>
#include "HelloWorld.h"
using namespace std;
void HelloWorld::hello()
cout << "Hello, World!" << endl;
"JHelloWorld.java"
public class JHelloWorld
public native void hello();
static
System.loadLibrary("hellolib");
public static void main(String[] argv)
JHelloWorld hw = new JHelloWorld();
hw.hello();
"JHelloWorld.cpp"
#include <iostream>
#include <jni.h>
#include "HelloWorld.h"
#include "JHelloWorld.h"
JNIEXPORT void JNICALL Java_JHelloWorld_hello (JNIEnv * env, jobject obj)
HelloWorld hw;
hw.hello();
All the files are in the same directory and all the processes are under the dirctory:
1. javac JHelloWorld.java
2. javah -classpath . JHelloWorld
3. g++ -c -I/usr/java/jdk1.3/include -I/usr/java/jdk1.3/include/linux JHelloWorld.cpp HelloWorld.cpp
4. ld -shared -o hellolib.so *.o
5. java -cp . -Djava.library.path=. JHelloWorld
Exception in thread "main" java.lang.UnsatisfiedLinkError: no hellolib in java.library.path
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1349)
at java.lang.Runtime.loadLibrary0(Runtime.java:749)
at java.lang.System.loadLibrary(System.java:820)
at JHelloWorld.<clinit>(JHelloWorld.java:7)
Tried another measure:
i) export LD_LIBRARY_PATH=.:$LD_LIBRARY_PATH
ii)java -cp . JHelloWorld
The same error came out as above.
I really don't know what is wrong with it.
Would you like to help me as soon as possible?
Thanks.
Regards,
Johnson

Answer 1

Hi Fabio,
Thanks a lot for your help.
It is very kind of you.
Regards,
Johnson