java.lang.UnsatisfiedLinkError: dalvik.system.PathClassLoader 找不到“liblivecamera.so.so”

Question

I am working on camera application. When I debug the application, it crashes and says

java.lang.UnsatisfiedLinkError: dalvik.system.PathClassLoader[DexPathList[[zip file "/data/app/org.tensorflow.lite.examples.detection-kuQobL0-J_-5EsHI7x5ShQ==/base.apk"],nativeLibraryDirectories=[/data/app/org.tensorflow.lite.examples.detection-kuQobL0-J_-5EsHI7x5ShQ==/lib/arm64, /data/app/org.tensorflow.lite.examples.detection-kuQobL0-J_-5EsHI7x5ShQ==/base.apk,/lib/arm64-v8a, /system/lib64. /vendor/lib64]]] couldn't find "liblibcamera.so.so"

It is showing this error at this line of code:-

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

My complete cameraview.java code

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.hardware.Camera;
import android.hardware.Camera.Size;
import android.os.Handler;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class CameraView extends SurfaceView implements Camera.PreviewCallback, SurfaceHolder.Callback,
        OCRThread.TextRegionsListener {

    private final List<Rect> regions = new ArrayList<>();

    private Camera mCamera;
    private byte[] mVideoSource;
    private Bitmap mBackBuffer;
    private OCRThread ocrThread;

    private Paint focusPaint;
    private Rect focusRect;

    private Paint paintText;

    private float horizontalRectRation;
    private float verticalRectRation;


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

    public CameraView(final Context context) {
        this(context, null);
    }

    public CameraView(final Context context, final AttributeSet attributes) {
        super(context, attributes);
        getHolder().addCallback(this);
        setWillNotDraw(false);
        focusPaint = new Paint();
        focusPaint.setColor(0xeed7d7d7);
        focusPaint.setStyle(Paint.Style.STROKE);
        focusPaint.setStrokeWidth(2);
        focusRect = new Rect(0, 0, 0, 0);

        paintText = new Paint();
        paintText.setColor(0xeeff0000);
        paintText.setStyle(Paint.Style.STROKE);
        paintText.setStrokeWidth(4);

        ocrThread = new OCRThread(context);
        horizontalRectRation = 1.0f;
        verticalRectRation = 1.0f;
    }

    public void setShowTextBounds(final boolean show) {
        regions.clear();
        ocrThread.setRegionsListener(show ? this : null);
        invalidate();
    }

    public void makeOCR(final OCRThread.TextRecognitionListener listener) {
        ocrThread.setTextRecognitionListener(listener);
    }

    public native void decode(final Bitmap pTarget, final byte[] pSource);


    @Override
    protected void onDraw(final Canvas canvas) {
        if (focusRect.width() > 0) {
            canvas.drawRect(focusRect, focusPaint);
        }
        if (mCamera != null) {
            mCamera.addCallbackBuffer(mVideoSource);
            drawTextBounds(canvas);
        }
    }

    private void drawTextBounds(final Canvas canvas) {
        for (Rect region : regions) {
            canvas.drawRect(region.left * horizontalRectRation, region.top * verticalRectRation,
                    region.right * horizontalRectRation, region.bottom * verticalRectRation, paintText);
        }
    }

    @Override
    public void onPreviewFrame(final byte[] bytes, final Camera camera) {
        decode(mBackBuffer, bytes);
        ocrThread.updateBitmap(mBackBuffer);
    }

    @Override
    public void surfaceCreated(final SurfaceHolder surfaceHolder) {
        try {
            mCamera = Camera.open(Camera.CameraInfo.CAMERA_FACING_BACK);
            mCamera.setDisplayOrientation(90);
            mCamera.setPreviewDisplay(surfaceHolder);
            mCamera.setPreviewCallbackWithBuffer(this);
            startOcrThread();
        } catch (IOException eIOException) {
            mCamera.release();
            mCamera = null;
            throw new IllegalStateException();
        }
    }

    private void startOcrThread() {
        ocrThread.start();
    }

    @Override
    public void surfaceChanged(final SurfaceHolder surfaceHolder, final int format, final int width, final int height) {
        mCamera.stopPreview();
        Size lSize = findBestResolution();
        updateTextRectsRatio(width, height, lSize);
        PixelFormat lPixelFormat = new PixelFormat();
        PixelFormat.getPixelFormatInfo(mCamera.getParameters()
                .getPreviewFormat(), lPixelFormat);
        int lSourceSize = lSize.width * lSize.height * lPixelFormat.bitsPerPixel / 8;
        mVideoSource = new byte[lSourceSize];
        mBackBuffer = Bitmap.createBitmap(lSize.width, lSize.height,
                Bitmap.Config.ARGB_8888);
        Camera.Parameters lParameters = mCamera.getParameters();
        lParameters.setPreviewSize(lSize.width, lSize.height);
        mCamera.setParameters(lParameters);
        mCamera.addCallbackBuffer(mVideoSource);
        mCamera.startPreview();
    }

    private Size findBestResolution() {
        List<Size> lSizes = mCamera.getParameters().getSupportedPreviewSizes();
        Size lSelectedSize = mCamera.new Size(0, 0);
        for (Size lSize : lSizes) {
            if ((lSize.width >= lSelectedSize.width) && (lSize.height >= lSelectedSize.height)) {
                lSelectedSize = lSize;
            }
        }
        if ((lSelectedSize.width == 0) || (lSelectedSize.height == 0)) {
            lSelectedSize = lSizes.get(0);
        }
        return lSelectedSize;
    }

    private void updateTextRectsRatio(final int width, final int height, final Size cameraSize) {
        verticalRectRation = ((float) height) / cameraSize.width;
        horizontalRectRation = ((float) width) / cameraSize.height;
    }

    @Override
    public void surfaceDestroyed(final SurfaceHolder surfaceHolder) {
        if (mCamera != null) {
            mCamera.stopPreview();
            mCamera.release();
            mCamera = null;
            mVideoSource = null;
            mBackBuffer = null;
            stopOcrThread();
        }
    }

    private void stopOcrThread() {
        boolean retry = true;
        ocrThread.cancel();
        ocrThread.setRegionsListener(null);
        while (retry) {
            try {
                ocrThread.join();
                retry = false;
            } catch (InterruptedException e) {
            }
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (event.getAction() == MotionEvent.ACTION_DOWN) {
            float x = event.getX();
            float y = event.getY();

            Rect touchRect = new Rect(
                    (int) (x - 100),
                    (int) (y - 100),
                    (int) (x + 100),
                    (int) (y + 100));

            final Rect targetFocusRect = new Rect(
                    touchRect.left * 2000 / this.getWidth() - 1000,
                    touchRect.top * 2000 / this.getHeight() - 1000,
                    touchRect.right * 2000 / this.getWidth() - 1000,
                    touchRect.bottom * 2000 / this.getHeight() - 1000);

            doTouchFocus(targetFocusRect);
            focusRect = touchRect;
            invalidate();

            Handler handler = new Handler();
            handler.postDelayed(new Runnable() {

                @Override
                public void run() {
                    focusRect = new Rect(0, 0, 0, 0);
                    invalidate();
                }
            }, 1000);
        }
        return false;
    }

    private void doTouchFocus(final Rect tfocusRect) {
        try {
            final List<Camera.Area> focusList = new ArrayList<Camera.Area>();
            Camera.Area focusArea = new Camera.Area(tfocusRect, 1000);
            focusList.add(focusArea);

            Camera.Parameters para = mCamera.getParameters();
            para.setFocusAreas(focusList);
            para.setMeteringAreas(focusList);
            mCamera.setParameters(para);
            mCamera.autoFocus(myAutoFocusCallback);
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

    Camera.AutoFocusCallback myAutoFocusCallback = new Camera.AutoFocusCallback() {

        @Override
        public void onAutoFocus(boolean arg0, Camera arg1) {
            if (arg0) {
                mCamera.cancelAutoFocus();
            }
        }
    };

    /**
     * {@inheritDoc}
     */
    @Override
    public void onTextRegionsRecognized(final List<Rect> textRegions) {
        regions.clear();
        regions.addAll(textRegions);
        invalidate();
    }
}

``

Answer 1

Your problem is the statement:

static {
        System.loadLibrary("libcamera.so");
}

System.loadLibrary is a Java method for loading a library in a platform-independant way, which means you don't have to specify the platform specific filename of the library, but instead you need to use the library name so without lib at the beginning and .so at the end. Java will make it platform specific for Linux by adding both.

So you have to change it to

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

and it will work and load libcamera.so (if this library is included in your app).