java.lang.ExceptionInInitializerError in Android Project

Question

I'm trying to create an Android Application that can record a video and, during recording, it should capture frames in order to process them. But when I try to run my app on my emulator (using Eclipse Juno, OpenCV4Android ver. 2.4.5, and android-ndk), I have this result in my logcat:

05-13 18:15:34.555: D/dalvikvm(1595): Trying to load lib /data/app-lib/com.example.provavideocapture-1/libjniVideoCapture.so 0x40ce89b0
05-13 18:15:34.555: E/dalvikvm(1595): dlopen("/data/app-lib/com.example.provavideocapture-1/libjniVideoCapture.so") failed: Cannot load library: soinfo_link_image(linker.cpp:1635): could not load library "libopencv_java.so" needed by "libjniVideoCapture.so"; caused by load_library(linker.cpp:745): library "libopencv_java.so" not found
05-13 18:15:34.555: W/dalvikvm(1595): Exception Ljava/lang/UnsatisfiedLinkError; thrown while initializing Lcom/example/provavideocapture/MainActivity;
05-13 18:15:34.555: W/dalvikvm(1595): Class init failed in newInstance call (Lcom/example/provavideocapture/MainActivity;)
05-13 18:15:34.555: D/AndroidRuntime(1595): Shutting down VM
05-13 18:15:34.555: W/dalvikvm(1595): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
05-13 18:15:34.575: E/AndroidRuntime(1595): FATAL EXCEPTION: main
05-13 18:15:34.575: E/AndroidRuntime(1595): java.lang.ExceptionInInitializerError
05-13 18:15:34.575: E/AndroidRuntime(1595):     at java.lang.Class.newInstanceImpl(Native Method)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at java.lang.Class.newInstance(Class.java:1319)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at android.app.Instrumentation.newActivity(Instrumentation.java:1054)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2097)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at android.os.Looper.loop(Looper.java:137)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at android.app.ActivityThread.main(ActivityThread.java:5041)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at java.lang.reflect.Method.invokeNative(Native Method)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at java.lang.reflect.Method.invoke(Method.java:511)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at dalvik.system.NativeStart.main(Native Method)
05-13 18:15:34.575: E/AndroidRuntime(1595): Caused by: java.lang.UnsatisfiedLinkError: Cannot load library: soinfo_link_image(linker.cpp:1635): could not load library "libopencv_java.so" needed by "libjniVideoCapture.so"; caused by load_library(linker.cpp:745): library "libopencv_java.so" not found
05-13 18:15:34.575: E/AndroidRuntime(1595):     at java.lang.Runtime.loadLibrary(Runtime.java:371)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at java.lang.System.loadLibrary(System.java:535)
05-13 18:15:34.575: E/AndroidRuntime(1595):     at com.example.provavideocapture.MainActivity.<clinit>(MainActivity.java:21)
05-13 18:15:34.575: E/AndroidRuntime(1595):     ... 15 more

It is my code:

1) MainActivity.java

package com.example.provavideocapture;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    TextView myTextField = (TextView)findViewById(R.id.myTextField);
    myTextField.setText(stringFromJNICPP()); 
}

public native String stringFromJNICPP();

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

}

2) jniVideoCapture.cpp

#include <jni.h>
#include <string.h>
#include <android/log.h>
#include <opencv2/opencv.hpp>

extern "C" {
JNIEXPORT jstring JNICALL Java_com_example_provavideocapture_MainActivity_stringFromJNICPP(JNIEnv * env, jobject obj);
};

    JNIEXPORT jstring JNICALL Java_com_example_provavideocapture_MainActivity_stringFromJNICPP(JNIEnv * env, jobject obj){

/*VideoCapture cap(0); //open the default camera
if (!cap.isOpened()) //check if we succedeed
    return -1;

Mat edges;
namedWindow("edges",1);
for(;;){
    Mat frame;
    cap>>frame;
    cvtColor(frame,edges,CV_BGR2GRAY);
    GaussianBlur(edges,edges,Size(7,7),1.5,1.5);
    Canny(edges,edges,0,30,3);
    imshow("edges",edges);
    if(waitKey(30)>=0) break;
}*/
return env->NewStringUTF("Hello From CPP");

}

3) Android.mk

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

include ../../Desktop/Android/OpenCV-2.4.5-android-sdk/sdk/native/jni/OpenCV.mk

LOCAL_MODULE    := jniVideoCapture
LOCAL_C_INCLUDES += $(LOCAL_PATH)
LOCAL_LDLIBS     += -llog -ldl
LOCAL_SRC_FILES := jniVideoCapture.cpp


include $(BUILD_SHARED_LIBRARY)

I've tried to copy manually in the dir libs of the project the library libopencv_java.so, taking it from an opencv tutorial project, and I've loaded it with the jniVideoCapture in the MainActivity, but without better results, because when I run the project, the library is automatically removed from libs/.

How can I fix this problem?

Answer 1

Just add line:

OPENCV_LIB_TYPE:=STATIC

right after:

include $(CLEAR_VARS)

You just didn't link (statically) opencv library to your project - this is a mistake.