public class AddArticle extends AppCompatActivity {
private static final int COD_FOTO = 20;

private static final String CARPETA_PRINCIPAL = "Hipack/";
private static final String CARPETA_IMAGEN = "HipackImages";
private static final String DIRECTORIO_IMAGEN = CARPETA_PRINCIPAL + CARPETA_IMAGEN;
private String path;
File fileImagen;
Bitmap bitmap;

private ImageView imgProducto;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_add_article);
    setTitle("Agregar Artículo");

    imgProducto = (ImageView)findViewById(R.id.imageProductoAddA);
}


public void tomarFoto(View vista){
    File miFile = new File(Environment.getExternalStorageDirectory(), DIRECTORIO_IMAGEN);
    boolean isCreada = miFile.exists();
    String nombreImagen = "";

    if (!isCreada){
        isCreada = miFile.mkdirs();
    } if (isCreada){
        nombreImagen = (System.currentTimeMillis()/1000) + ".jpg";
    }

        fileImagen = new File(Environment.getExternalStorageDirectory(), nombreImagen + ".jpg");

        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(fileImagen)); // Aqui me da el error
        startActivityForResult(intent, COD_FOTO);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    switch (requestCode){
        case COD_FOTO:
            MediaScannerConnection.scanFile(this, new String[]{path}, null,
                    new MediaScannerConnection.OnScanCompletedListener() {
                        @Override
                        public void onScanCompleted(String path, Uri uri) {
                            Log.i("Ruta de almacenamiento", "Path: "+path);
                        }
                    });
            bitmap = BitmapFactory.decodeFile(path);
            imgProducto.setImageBitmap(bitmap);
            break;
        }
    }
}

E/AndroidRuntime: FATAL EXCEPTION: main
              Process: com.example.humberto.hipackpro2, PID: 31387
              java.lang.IllegalStateException: Could not execute method for android:onClick
                  at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:389)
                  at android.view.View.performClick(View.java:6305)
                  at android.view.View$PerformClick.run(View.java:24840)
                  at android.os.Handler.handleCallback(Handler.java:790)
                  at android.os.Handler.dispatchMessage(Handler.java:99)
                  at android.os.Looper.loop(Looper.java:164)
                  at android.app.ActivityThread.main(ActivityThread.java:6501)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
               Caused by: java.lang.reflect.InvocationTargetException
                  at java.lang.reflect.Method.invoke(Native Method)
                  at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:384)
                  at android.view.View.performClick(View.java:6305)
                  at android.view.View$PerformClick.run(View.java:24840)
                  at android.os.Handler.handleCallback(Handler.java:790)
                  at android.os.Handler.dispatchMessage(Handler.java:99)
                  at android.os.Looper.loop(Looper.java:164)
                  at android.app.ActivityThread.main(ActivityThread.java:6501)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
               Caused by: android.os.FileUriExposedException: file:///storage/emulated/0/1537456175.jpg.jpg exposed beyond app through ClipData.Item.getUri()
                  at android.os.StrictMode.onFileUriExposed(StrictMode.java:1962)
                  at android.net.Uri.checkFileUriExposed(Uri.java:2356)
                  at android.content.ClipData.prepareToLeaveProcess(ClipData.java:942)
                  at android.content.Intent.prepareToLeaveProcess(Intent.java:9850)
                  at android.content.Intent.prepareToLeaveProcess(Intent.java:9835)
                  at android.app.Instrumentation.execStartActivity(Instrumentation.java:1612)
                  at android.app.Activity.startActivityForResult(Activity.java:4514)
                  at android.support.v4.app.BaseFragmentActivityApi16.startActivityForResult(BaseFragmentActivityApi16.java:54)
                  at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:68)
                  at android.app.Activity.startActivityForResult(Activity.java:4472)
                  at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:751)
                  at com.example.humberto.hipackpro2.AddArticle.tomarFoto(AddArticle.java:206) //Aqui me manda a la línea del código
                  at java.lang.reflect.Method.invoke(Native Method)
                  at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:384)
                  at android.view.View.performClick(View.java:6305)
                  at android.view.View$PerformClick.run(View.java:24840)
                  at android.os.Handler.handleCallback(Handler.java:790)
                  at android.os.Handler.dispatchMessage(Handler.java:99)
                  at android.os.Looper.loop(Looper.java:164)
                  at android.app.ActivityThread.main(ActivityThread.java:6501)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    super.onActivityResult(requestCode, resultCode, data);

    switch (requestCode) {
        case COD_FOTO:
            if (resultCode == RESULT_OK) {

                Uri uri = data.getData();
                String[] projection = {MediaStore.Images.Media.DATA};
                Cursor cursor = getContentResolver().query(uri, projection, null, null, null);
                cursor.moveToFirst();
                int columnIndex = cursor.getColumnIndex(projection[0]);
                String filepath = cursor.getString(columnIndex);
                cursor.close();

                bitmap = BitmapFactory.decodeFile(filepath);
                imgProducto.setImageBitmap(bitmap);
            }
            break;
        default:
            break;
    }
}