我有一个Android应用程序，它在某些手机上崩溃了，而在其他手机上却崩溃了。它的下载量约为5,000，到目前为止，已收到约50个崩溃报告。但是，根据我从用户那里获得的评分/评论（说是强制崩溃）来看，我认为受影响用户的百分比实际上要高得多。
由于该问题不会影响我的手机，因此我无法重现该错误并进行调试。
该应用程序从相机拍摄照片，在其上叠加一个位图，然后将生成的图像保存到SD卡。
下面是我的onPictureTaken PictureCallback方法的代码。
private Camera.PictureCallback mPicture = new Camera.PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
captureBtn.setVisibility(ImageButton.INVISIBLE);
File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
if (pictureFile == null){
return;
}
BitmapFactory.Options options = new BitmapFactory.Options();
Bitmap mutableBitmap = null;
Bitmap finalBitmap = null;
byte[] byteArray = null;
try {
mutableBitmap = BitmapFactory.decodeByteArray(data, 0, data.length, options).copy(Bitmap.Config.RGB_565, true);
Matrix matrix = new Matrix();
int width = mutableBitmap.getWidth();
int height = mutableBitmap.getHeight();
int newWidth = overlayView.getDrawable().getBounds().width();
int newHeight = overlayView.getDrawable().getBounds().height();
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
matrix.postScale(scaleWidth, scaleHeight);
matrix.postRotate(90);
Bitmap resizedBitmap = Bitmap.createBitmap(mutableBitmap, 0, 0, mutableBitmap.getWidth(), mutableBitmap.getHeight(), matrix, true);
finalBitmap = resizedBitmap.copy(Bitmap.Config.RGB_565, true);
Canvas canvas = new Canvas(finalBitmap);
Bitmap overlayBitmap = null;
if (mWeaponType == wep1) {
overlayBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.wep1);
} else if (mWeaponType == wep2) {
overlayBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.wep2);
}
if (overlayBitmap != null) {
matrix = new Matrix();
matrix.postRotate(90);
Bitmap resizedOverlay = Bitmap.createBitmap(overlayBitmap, 0, 0, overlayBitmap.getWidth(), overlayBitmap.getHeight(), matrix, true);
canvas.drawBitmap(resizedOverlay, 0, 0, new Paint());
canvas.scale(50, 0);
canvas.save();
//finalBitmap is the image with the overlay on it
// rotate image to save in landscape mode
matrix = new Matrix();
matrix.postRotate(270);
finalBitmap = Bitmap.createBitmap(finalBitmap, 0, 0, finalBitmap.getWidth(), finalBitmap.getHeight(), matrix,
true);
// convert final bitmap to byte array
ByteArrayOutputStream stream = new ByteArrayOutputStream();
finalBitmap.compress(Bitmap.CompressFormat.PNG, 100, stream);
byteArray = stream.toByteArray();
}
}
catch(OutOfMemoryError e) {
//fail
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(byteArray);
fos.close();
// Notify system that SD card has been updated
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://"+ Environment.getExternalStorageDirectory())));
Log.i(TAG, "Picture saved, intent broadcast that SD has been updated");
} catch (FileNotFoundException e) {
Log.d(TAG, "File not found: " + e.getMessage());
} catch (IOException e) {
Log.d(TAG, "Error accessing file: " + e.getMessage());
} catch (NullPointerException e) {
}
finally {
mCamera.startPreview();
captureBtn.setVisibility(ImageButton.VISIBLE);
}
}
};
我得到一个NullPointerException，如下所示：
java.lang.NullPointerException
at java.io.FileOutputStream.write(FileOutputStream.java:256)
at com.mypackage.MyActivity.onPictureTaken(MyActivity.java:215)
哪一个是
fos.write(byteArray);
线。
上面列出的
getOutputMediaFile方法如下：/** Create a File for saving an image or video */
private static File getOutputMediaFile(int type){
// To be safe, you should check that the SDCard is mounted
// using Environment.getExternalStorageState() before doing this.
File mediaStorageDir = Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES);
// Create the storage directory if it does not exist
if (! mediaStorageDir.exists()){
if (! mediaStorageDir.mkdirs()){
Log.d("HalfLife2 Booth", "failed to create directory");
return null;
}
}
// Create a media file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
File mediaFile;
if (type == MEDIA_TYPE_IMAGE){
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"IMG_"+ timeStamp + ".jpg");
} else if(type == MEDIA_TYPE_VIDEO) {
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"VID_"+ timeStamp + ".mp4");
} else {
return null;
}
return mediaFile;
}
我认为问题可能出在这里，试图获取输出媒体文件。我尝试更新该应用程序以使用：
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), "MyApp");
相反，一位用户报告了该问题已得到解决，但几位用户报告了该问题仍然存在。
有什么想法吗？当我无法重现或接近它时，我发现这是一个调试/修复的棘手问题。
最佳答案
确保以原始格式缩放图片。我发现某些手机型号上的原始图像很大。如果图像很大，我建议缩放图像，因为这样会使虚拟机的内存不足。
例：
imageRef = sd_card_path+"/"+ImageName;
BitmapFactory.Options resample = new BitmapFactory.Options();
resample.inJustDecodeBounds = true;
BitmapFactory.decodeFile(imageRef, resample);
int width = resample.outWidth;
int height = resample.outHeight;
if(width*height > utility.IMAGE_SIZE_MIN){
int imageSizef = (int)(width*height/utility.IMAGE_SIZE_MIN);
String imageSize = imageSizef+"";
resample.inSampleSize = Integer.parseInt(imageSize);
resample.inJustDecodeBounds = false;
image.setImageBitmap(BitmapFactory.decodeFile(imageRef , resample));
}else{
image.setImageBitmap(BitmapFactory.decodeFile(imageRef ));
}