JNA

package jna;

import com.sun.jna.Library;
import com.sun.jna.Native;

public class pro {
    
    static String PATH = "C:/data/ex070801.dll";
    public static void main(String[] args) {
        Sample lib = Sample.ex;
    System.out.println(lib.f(20));
     System.out.println(lib.g(20));
    }
    
    interface Sample extends Library{
    Sample ex = (Sample) Native.loadLibrary(PATH, Sample.class);
     int f(int x);
     int g(int x);
    }
}