我试图将图片desert.png从android上传到php服务器，但它对我不起作用，它给了我这个错误日志： E /错误：（1450）：/ debug.png：打开失败：EROFS（只读文件系统） 这是我的代码：
/**
* Background Async Task to upload file
* */
class UploadFileToURL extends AsyncTask<String, String, String> {
/**
* Before starting background thread
* Show Progress Bar Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
showDialog(progress_bar_type);
}
/**
* Uploading file in background thread
* */
@Override
protected String doInBackground(String... f_url) {
int count;
try {
URL url = new URL(f_url[0]);
URLConnection conection = url.openConnection();
conection.connect();
// this will be useful so that you can show a tipical 0-100% progress bar
int lenghtOfFile = conection.getContentLength();
Log.i("lenghtOfFile",lenghtOfFile+"");
// download the file
InputStream input = new BufferedInputStream(url.openStream(), 8192);
Log.i("InputStream","InputStream");
// Output stream
OutputStream output = new FileOutputStream("desert.png");
Log.i("OutputStream","OutputStream");
Bitmap bitmap = BitmapFactory.decodeResource(getResources(),R.drawable.desert);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 90, stream); //compress to which format you want.
byte [] byte_arr = stream.toByteArray();
byte data[] = new byte[1024];
long sentByte = 0;
while ((count = input.read(byte_arr)) != -1) {
output.write(byte_arr, 0, count);
sentByte += count;
// passed=passedTime -previosTime ;
// previosTime = passed ;
// publishing the progress....
// After this onProgressUpdate will be called
publishProgress(""+(int)((sentByte*100)/lenghtOfFile));
Log.i("log_lenghtOfFile",lenghtOfFile+"" );
Log.i("log_total",sentByte+"" );
Log.i("log_ourcentage",(int)((sentByte*100)/lenghtOfFile)+"" );
// Log.i("log_Debit",passedTime +"" );
// writing data to file
output.write(data, 0, count);
}
// flushing output
output.flush();
// closing streams
output.close();
input.close();
} catch (Exception e) {
Log.e("Error: ", e.getMessage());
}
return null;
}
/**
* Updating progress bar
* */
protected void onProgressUpdate(String... progress) {
// setting progress percentage
pDialog.setProgress(Integer.parseInt(progress[0]));
}
/**
* After completing background task
* Dismiss the progress dialog
* **/
@Override
protected void onPostExecute(String file_url) {
// dismiss the dialog after the file was downloaded
dismissDialog(progress_bar_type);
// Displaying downloaded image into image view
// Reading image path from sdcard
// String imagePath = Environment.getExternalStorageDirectory().toString() + "/downloadedfile.jpg";
// setting downloaded into image view
// my_image.setImageDrawable(Drawable.createFromPath(imagePath));
}
}