从Java运行本机dll时，线程“主” java.lang.UnsatisfiedLinkError中的异常：Native.initiate（I）V

Question

This is the Native.cpp :

// Native.cpp : Defines the exported functions for the DLL application.
//
#include "stdafx.h"
#define ALLEGRO_NO_MAGIC_MAIN
#include <stdio.h>
#include <string>
#include <windows.h>
#include "generic_interface.h"
#include "NativeC.h"

using namespace std;

// Some useful defines I liked from Sun's stuff
#define JNIEXPORT __declspec(dllexport) 
#define JNICALL __cdecl
#define jint long


typedef ExportedClass* (__cdecl *exported_class)();
HINSTANCE temptDLL;
ExportedClass** importedClasses;
char** classNamePerIndex;
int libraryLength = 0;

JNIEXPORT void JNICALL _JAVA_initiate(HNative *self, jint libraryLength) {
    importedClasses = new ExportedClass*[libraryLength];
    classNamePerIndex = new char*[libraryLength];
}

and the Java class that implements and loads this native dll generated from the above Native.cpp file is like :

public class Native {
    // guess?
  native public void initiate(int libraryLength);


    // Loads the file Native.DLL at run-time
  static {
    System.loadLibrary("Native");
  }

    // Constructor
  public Native()
  {
  }

}

But while calling

(new Native()).initiate(1);

I get this run time error :

Exception in thread "main" java.lang.UnsatisfiedLinkError: Native.initiate(I)V

I have tried to rename _JAVA_initiate to JAVA_initiate and NATIVE_initiate and _JAVA_NATIVE_inititate and even JAVA_NATIVE_inititate, but It did not work still

The library is loading perfectly fine, just while calling the native method, it is giving link error.

EDIT: Below listed is the NativeC.h that is already included in the Native.cpp

/*  DO NOT EDIT - automatically generated by javah  */
#include "Native.h"

/*  Header for class Native  */

#ifndef _Included_Native
#define _Included_Native

typedef struct ClassNative {
#pragma pack(push,4)
    int32_t MSReserved;
    struct Hjava_lang_String * string_;
    /*boolean*/ long boolean_;
    /*byte*/ long byte_;
    /*char*/ long char_;
    double double_;
    float float_;
    long int_;
    int64_t long_;
    /*short*/ long short_;
    struct Hjava_lang_String * w;
    long x;
    long y;
#pragma pack(pop)
} ClassNative;
#define HNative ClassNative

#ifdef __cplusplus
extern "C" {
#endif
__declspec(dllexport) void __cdecl _JAVA_initiate (struct HNative *, long);
__declspec(dllexport) void __cdecl _JAVA_loadLibraryAndInitiate (struct HNative *, struct     Hjava_lang_String *);
__declspec(dllexport) long __cdecl _JAVA_evaluateLibrary (struct HNative *, struct             Hjava_lang_String *, struct Hjava_lang_String *);
#ifdef __cplusplus
}
#endif
#endif

Answer 1

You need to use javah to generate the signature for your function, as the one you're using is missing a number of things. In particular, the JNI environment, which gets passed as an argument to every function.

Answer 2

您需要实现在使用javah生成的Native.h中声明的方法，通常一个类有一个包，这是方法名的一部分。