unable to decode stream java.io.FileNotFoundExcept

问题:

hello i'm trying to save pictures taken on my application, but when i try to access the memory to place the data, an error comes out

unable to decode stream java.io.FileNotFoundException /storage/emulated/0 open failed:ENOENT(No such file or directory)

this is my code.

            Camera.PictureCallback mPictureCallback = new Camera.PictureCallback() {

        public void onPictureTaken(byte[] data, Camera camera) {
            // TODO Auto-generated method stub
            if (data != null){
                //Intent mIntent = new Intent();
                //mIntent.putExtra("image",imageData);

                mCamera.stopPreview();
                mPreviewRunning = false;
                mCamera.release();

                 try{
                     BitmapFactory.Options opts = new BitmapFactory.Options();
                     Bitmap bitmap= BitmapFactory.decodeByteArray(data, 0, data.length,opts);
                     bitmap = Bitmap.createScaledBitmap(bitmap, 300, 300, false);
                     int width = bitmap.getWidth();
                     int height = bitmap.getHeight();
                     int newWidth = 300;
                     int newHeight = 300;

                     // calculate the scale - in this case = 0.4f
                     float scaleWidth = ((float) newWidth) / width;
                     float scaleHeight = ((float) newHeight) / height;

                     // createa matrix for the manipulation
                     Matrix matrix = new Matrix();
                     // resize the bit map
                     matrix.postScale(scaleWidth, scaleHeight);
                     // rotate the Bitmap
                     matrix.postRotate(-90);
                     Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0,
                             width, height, matrix, true);
                     Camera_local_db.image.setImageBitmap(resizedBitmap);

                 }catch(Exception e){
                     e.printStackTrace();
                 }
               // StoreByteImage(mContext, imageData, 50,"ImageName");
                //setResult(FOTO_MODE, mIntent);
                setResult(585);
                finish();
            }       
        }
    };


    Camera.PictureCallback jpegCallback = new Camera. PictureCallback() {
    @Override
    public void onPictureTaken(byte[] data, Camera camera) {


        File dir_image2 = new  File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM),"dddd.jpg");
        dir_image2.mkdirs();  //AGAIN CHOOSING FOLDER FOR THE PICTURE(WHICH IS LIKE A SURFACEVIEW 
                                //SCREENSHOT)
        if (!dir_image2.mkdirs()) {
            Log.e(TAG, "Directory not created");
        }


        File tmpFile = new File(dir_image2,"TempGhost.jpg"); //MAKING A FILE IN THE PATH                 
                        //dir_image2(SEE RIGHT ABOVE) AND NAMING IT "TempGhost.jpg" OR ANYTHING ELSE
        try {//SAVING
            FileOutputStream fos = new FileOutputStream(tmpFile);
            fos.write(data);
            fos.close();
            //grabImage();
        } catch (FileNotFoundException e) {
            Toast.makeText(getApplicationContext(),"Error",Toast.LENGTH_LONG).show();
        } catch (IOException e) {
            Toast.makeText(getApplicationContext(),"Error",Toast.LENGTH_LONG).show();
        }
        //String path = Environment.getExternalStoragePublicDirectory(    Environment.DIRECTORY_MOVIES); File file = new File(path, "/" + dir_image2);
        //String path = (Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM)+  
          //      File.separator+"TempGhost.jpg");//<---

        BitmapFactory.Options options = new BitmapFactory.Options();//<---
        options.inPreferredConfig = Bitmap.Config.ARGB_8888;//<---
        bmp1 = BitmapFactory.decodeFile(tmpFile.toString(), options);//<---
        //THE LINES ABOVE READ THE FILE WE SAVED BEFORE AND CONVERT IT INTO A BitMap
        Camera_local_db.image.setImageBitmap(bmp1);
        //camera_image.setImageBitmap(bmp1); //SETTING THE BitMap AS IMAGE IN AN IMAGEVIEW(SOMETHING
                                    //LIKE A BACKGROUNG FOR THE LAYOUT)
       // TakeScreenshot();//CALLING THIS METHOD TO TAKE A SCREENSHOT

    }
    };

回答1:

You need to write to external storage, make sure you added the permission:

<manifest ...>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    ...
</manifest>

Checks if external storage is available for read and write:

public boolean isExternalStorageWritable() {
    String state = Environment.getExternalStorageState();
    if (Environment.MEDIA_MOUNTED.equals(state)) {
        return true;
    }
    return false;
}

Use the root of the public directory instead of using the root of Android.

If you want to save public files on the external storage, use the getExternalStoragePublicDirectory()

public File getAlbumStorageDir(String albumName) {
    // Get the directory for the user's public pictures directory. 
    File file = new File(Environment.getExternalStoragePublicDirectory(
            Environment.DIRECTORY_DCIM), albumName);
    if (!file.mkdirs()) {
        Log.e(LOG_TAG, "Directory not created");
    }
    return file;
}

If you want to save files that are private to your app, use the getExternalFilesDir()

public File getAlbumStorageDir(Context context, String albumName) {
    // Get the directory for the app's private pictures directory. 
    File file = new File(context.getExternalFilesDir(
            Environment.DIRECTORY_DCIM), albumName);
    if (!file.mkdirs()) {
        Log.e(LOG_TAG, "Directory not created");
    }
    return file;
}

More information on the link http://developer.android.com/training/basics/data-storage/files.html

回答2:

I had the same error, and the only problem was the permission in android manifest.

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />


<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

回答3:

First, you are writing the image to a different location than you are reading it from. Rather than rebuild path, use the tmpFile value that you already have.

Second, do not use getRootDirectory() to get the DCIM directory. Use getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM).

Third, use Log methods to log exceptions, rather than just display a Toast, as you may miss the Toast and you do not get the stack trace associated with your exception.

回答4:

I solved using this:

private static final int WRITE_PERMISSION = 0x01;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    requestWritePermission();
}

@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
    if(requestCode == WRITE_PERMISSION){
        if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            Log.d(LOG_TAG, "Write Permission Failed");
            Toast.makeText(this, "You must allow permission write external storage to your mobile device.", Toast.LENGTH_SHORT).show();
            finish();
        }
    }
}

private void requestWritePermission(){
    if(checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE)!=PackageManager.PERMISSION_GRANTED){
        ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},WRITE_PERMISSION);
    }
}

回答5:

Add this permission in Android Manifest.

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

If it fails with this permission is present already, then you need to check your app's target SDK level. If it is targetSdkVersion => 23, then you need to request permissions at Run Time. Here