Question

I am practising JNI and created the shared library file Samplelib.so. I added the directory in which the library file is created, to the java.library.path and when I run the java file, I get java.lang.UnsatisfiedLinkError. Here is my Sample.java.

import java.util.*;
public class Sample{
public native int intmethod(int n);
public native String stringmethod(String s);
public static void main(String[] args) {
    try{
    //System.setProperty( "java.library.path", "/home/sudhagar/Project" );
    System.load("libSample");
    Sample sample=new Sample();
    int sq=sample.intmethod(2);
    String text=sample.stringmethod("JAVA");
    System.out.println(sq);
    System.out.println(text);
}
catch(UnsatisfiedLinkError e){
    String property = System.getProperty("java.library.path");
    StringTokenizer parser = new StringTokenizer(property, ";");
    while (parser.hasMoreTokens()) {
    System.err.println(parser.nextToken());
    }
}
}
}

My Sample.c file,

#include "Sample.h"
#include <string.h>

JNIEXPORT jint  JNICALL Java_Sample_intmethod
(JNIEnv *env, jobject obj, jint n){
    return n*n;
}

JNIEXPORT jstring JNICALL Java_Sample_stringmethod
(JNIEnv *env, jobject obj, jstring n){
    return n;
}   

void main(){}   

I used following command to create the create the shared library,
gcc -shared -I/…/include -I/…/include/linux -o libSample.so Sample.c

Answer 1

Use

  System.loadLibrary("Samplelib");

instead of

System.load("Samplelib");