java.lang.NullPointerException: Attempt to get length of null array

[ajinkya976]

Only media button is working for me.

When i click picture on camera button, nothing is happening on click of tick.

On click of scan button also nothing is happening.

can someone please help on above 2 points.

below is my code.

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import android.Manifest;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import com.scanlibrary.ScanActivity;
import com.scanlibrary.ScanConstants;

import java.io.IOException;

public class MainActivity extends AppCompatActivity {

    ImageView scannedImage;
    private Button scanButton;
    private Button cameraButton;
    private Button mediaButton;
    private static final int REQUEST_CODE = 99;
    private static final int STORAGE_CODE = 100;
    private static final int MY_WRITE_EXTERNAL_STORAGE = 101;
    private static final int MY_READ_EXTERNAL_STORAGE = 102;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        scannedImage = findViewById(R.id.scannedImage);
        scanButton = (Button) findViewById(R.id.scanButton);
        scanButton.setOnClickListener(new ScanButtonClickListener());
        cameraButton = (Button) findViewById(R.id.cameraButton);
        cameraButton.setOnClickListener(new ScanButtonClickListener(ScanConstants.OPEN_CAMERA));
        mediaButton = (Button) findViewById(R.id.mediaButton);
        mediaButton.setOnClickListener(new ScanButtonClickListener(ScanConstants.OPEN_MEDIA));

        if (checkSelfPermission(Manifest.permission.CAMERA)
                != PackageManager.PERMISSION_GRANTED) {
            requestPermissions(new String[]{Manifest.permission.CAMERA,Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.READ_EXTERNAL_STORAGE},
                    STORAGE_CODE);
        }

    }

    private class ScanButtonClickListener implements View.OnClickListener {

        private int preference;

        public ScanButtonClickListener(int preference) {
            this.preference = preference;
        }

        public ScanButtonClickListener() {
        }

        @Override
        public void onClick(View v) {
            startScan(preference);
        }
    }

    protected void startScan(int preference) {
        Intent intent = new Intent(this, ScanActivity.class);
        intent.putExtra(ScanConstants.OPEN_INTENT_PREFERENCE, preference);
        startActivityForResult(intent, REQUEST_CODE);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        try {
            super.onActivityResult(requestCode, resultCode, data);
            if (requestCode == REQUEST_CODE && resultCode == Activity.RESULT_OK) {
                Uri uri = data.getExtras().getParcelable(ScanConstants.SCANNED_RESULT);
                Bitmap bitmap = null;
                try {
                    bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), uri);
                    getContentResolver().delete(uri, null, null);
                    scannedImage.setImageBitmap(bitmap);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }catch (Exception e)
        {
            e.printStackTrace();
        }
    }

    private Bitmap convertByteArrayToBitmap(byte[] data) {
        return BitmapFactory.decodeByteArray(data, 0, data.length);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {

        switch (requestCode)
        {
            case STORAGE_CODE:{
                if(grantResults.length>0 && grantResults[0]==PackageManager.PERMISSION_GRANTED)
                {//permission was granted from popup
                    Toast.makeText(this,"Permission Granted...!",Toast.LENGTH_SHORT).show();
                }
                else
                {//permission was denied from popup
                    Toast.makeText(this,"Permission denied...!",Toast.LENGTH_SHORT).show();

                }
            }
        }
    }
}

When i click on CAMERA button i am getting below error.

W/System.err: java.lang.NullPointerException: Attempt to get length of null array
        at com.scanlibrary.PickImageFragment.clearTempImages(PickImageFragment.java:67)
        at com.scanlibrary.PickImageFragment.createImageFile(PickImageFragment.java:133)
        at com.scanlibrary.PickImageFragment.openCamera(PickImageFragment.java:117)
        at com.scanlibrary.PickImageFragment.handleIntentPreference(PickImageFragment.java:77)
        at com.scanlibrary.PickImageFragment.init(PickImageFragment.java:58)
        at com.scanlibrary.PickImageFragment.onCreateView(PickImageFragment.java:48)
        at android.app.Fragment.performCreateView(Fragment.java:2534)
        at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1303)
        at android.app.FragmentManagerImpl.addAddedFragments(FragmentManager.java:2431)
        at android.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2210)
        at android.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2166)
        at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2067)
        at android.app.FragmentManagerImpl.dispatchMoveToState(FragmentManager.java:3057)
W/System.err:     at android.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:3004)
        at android.app.FragmentController.dispatchActivityCreated(FragmentController.java:184)
        at android.app.Activity.performCreate(Activity.java:7822)
        at android.app.Activity.performCreate(Activity.java:7804)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1318)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3349)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3513)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2109)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7682)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:516)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)

can someone please help on above.

[mauclores]

See if this can help: https://github.com/jhansireddy/AndroidScannerDemo/issues/112#issuecomment-626151977