CODEWITHSUNDEEP
androidandroid-ndknative
Rikki Tikki Tavi
Rikki Tikki Tavi

Reputation: 3139

UnsatisfiedLinkError implementing simple NDK setup

I found some similar questions, but their answers didn't help me. I went through this tutorial http://mindtherobot.com/blog/452/android-beginners-ndk-setup-step-by-step/ and get some problems with it.

My Android.mk file :

     LOCAL_PATH := $(call my-dir)
 MY_PATH := $(LOCAL_PATH)
 include $(call all-subdir-makefiles)

 include $(CLEAR_VARS)

 LOCAL_PATH := $(MY_PATH)

 LOCAL_LDLIBS := -llog -ldl
 LOCAL_MODULE    := ndkfoo
 LOCAL_SRC_FILES := ndkfoo.c

 include $(BUILD_SHARED_LIBRARY)

And my c-class ndkfoo.c :

    #include <jni.h>  
#include <string.h>  
#include <android/log.h>  
#include <string.h>
#include <jni.h>
jstring Java_com_example_ocrrecognise_ndkfoo_MainActivity_invokeNativeFunction(JNIEnv* env, jobject javaThis) {
  return (*env)->NewStringUTF(env, "Hello from native code!");
}

and MainActivity:

public class MainActivity extends Activity {
static {  
    System.loadLibrary("ndkfoo");  
} 
private native String invokeNativeFunction();  
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    final Button button = (Button) findViewById(R.id.button_id);
    button.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) 
        {
              try{
                  String hello = invokeNativeFunction();
                  Log.i("string func", hello);
              }catch (UnsatisfiedLinkError e)
              {
                  e.printStackTrace();
              }

              //new AlertDialog.Builder(MainActivity.this).setMessage(hello).show();
        }
    });

}

But I've got 

 No implementation found for native Lcom/example/ocrrecognise/MainActivity;.invokeNativeFunction ()Ljava/lang/String;
 java.lang.UnsatisfiedLinkError: invokeNativeFunction
    at com.example.ocrrecognise.MainActivity.invokeNativeFunction(Native Method)
    at com.example.ocrrecognise.MainActivity.access$0(MainActivity.java:14)
    at com.example.ocrrecognise.MainActivity$1.onClick(MainActivity.java:24)
    at android.view.View.performClick(View.java:2485)
    at android.view.View$PerformClick.run(View.java:9080)
    at android.os.Handler.handleCallback(Handler.java:587)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:123)
    at android.app.ActivityThread.main(ActivityThread.java:3687)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:507)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)

My in the ndkfoo.c I put right package name. Help with it please.

Upvotes: 2

Views: 553

Answers (2)

Sumeet Khullar
Sumeet Khullar

Reputation: 463

From the error

 No implementation found for native Lcom/example/ocrrecognise/MainActivity;.invokeNativeFunction

it appears that your main activity is in the package com.example.ocrrecognise. If you place it in package com_example_ocrrecognise_ndkfoo, it should work, since that is the prefix that you are using in declaring the function in your native code.

Upvotes: 1

Givi
Givi

Reputation: 3283

In what package your Activity is in? Please mind that is should be under com.example.ocrrecognise.ndkfoo. How did you compile your c code?

Did you put the compile .so file under /libs/armeabi in your project?

Upvotes: 2

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