Weird java.lang.UnsatisfiedLinkError: Native method not found:

Question

I am using NDK+OpenCV to develop the apps. I have the following issue:

I put all the native method in FoodRecgNativeLib.java and I want to read opencv Matrix from file:

//in FoodRecgNativeLib.java

public static void NativeLoadFile(String path, String tag, Mat result)
{
    loadsfile(path,tag,result.nativeObj);
    return;
}
public native static void loadsfile(String path, String tag, long addr);

//.h file
/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class ca_uwo_csd_Threads_FoodRecgNativeLib */

#ifndef _Included_ca_uwo_csd_Threads_FoodRecgNativeLib
#define _Included_ca_uwo_csd_Threads_FoodRecgNativeLib
#ifdef __cplusplus
extern "C" {
#endif
JNIEXPORT void JNICALL Java_ca_uwo_csd_Threads_FoodRecgNativeLib_loadsfile
(JNIEnv *, jclass, jstring, jstring, jlong);
#ifdef __cplusplus
}
#endif
#endif

//in .cpp file, .h file is included

JNIEXPORT void JNICALL Java_ca_uwo_csd_Threads_FoodRecgNativeLib_loadsfile
 (JNIEnv *env, jobject cls, jstring path, jstring tag, jlong result_addr)
{
    cv::FileStorage fs(jstring2str(env,path), FileStorage::READ);
    Mat& data = *(Mat*)result_addr;;
    fs[jstring2str(env,tag)] >> data;
}

Could anyone check what's wrong with my code?

Answer 1

The declaration and implementation signatures of Java_ca_uwo_csd_Threads_FoodRecgNativeLib_loadsfile don't match. Change the second parameter type in the implementation from jobject to jclass .

Answer 2

您可能忘记了通过以下方式加载本机库

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