Develop Reference

Check if a file has been written to in Android

I have a question about Android programming. Basically, I am unsure of where to check where my file is, and if I wrote to it correctly. I want to locate where the file is, and I also want to know whether or not I wrote to it correctly. Below is the code I have come up with:
String lsNow = "testing";
try {
fos = openFileOutput("output.txt", Context.MODE_APPEND);
fos.write(lsNow.getBytes());
fos.close();
}
catch{
...
}
Where can I find output.txt? Might anyone know how to check this all out? if so, that would be great! I am using an emulator by the way. If I were to do this on a real Android, how would one approach this also? (Just for future reference)

You Test it in Two ways
Using File Explorer
Go to DDMS perspective--> Open File Explorer-->location of the file
Pragrammatically by using exits() method
File file = new File(context.getFilesDir(), filename);
if(file.exists())

Using openFileOutput(...) means the file will be written to internal storage on the Android device in an area which is secure from access by other apps.
If you want to make sure the file is written correctly then make sure your catch block handles any failures (if it is called then the file writing has failed).
To access the file once it has been written use openFileInput(...).

FileNotFoundException in an Android app: can't find the route to copy the file

Good afternoon everyone,
I'm having a problem here with an CSV file that I wanna use to fill a dynamic table in Android.
I placed the file in the "data" folder of my emulator, and I did the following declaration to create my file variable:
file = new File("/data/Motors.csv");
I used a CSVReader class posted on another thread from this page (Link to the class) and also declared the following line to do the parse:
readerCSV = new CSVReader(new FileReader(file),';','"',0);
In the last line, the programmer to be able to create the variable has to send as parameters a Reader (Or a FileReader, it doesn't make a difference), the separator char, the quote char and the number of how many lines the CSV reader has to skip.
The problem comes that no matter in which directory (Not even in the root directory, which Java tells me that it's "/" through the file.getAbsolutePath(); method) it always gets to the point when the program throws the FileNotFoundException and I'm getting a bit frustrated because I have 2 days already with this problem.
If someone could please help me to get a bit of orientation of what I should do to get the file from the right directory... It would be a lot of help and I can go further with the code I have to finish.
Many thanks in advance!!!!
EDIT
I found a solution to open my file:
I have used 2 file variables: one gets the rout of the External Storage Directory (see first answer in the following link) and the other is declared as a new file, like the following lines in the code:
route = Environment.getExternalStorageDirectory();
file = new File(route,"Motors.csv");
Later I used again the CSV reader class that I found, where the first parameter is from the FileReader type (Sorry #Rajesh, but I couldn't use your alternative because you passed a FileDescription parameter from the AssetManager to the CSV reader class and then I had to change the whole class and that didn't help my problem at all).
Now I don't get the exception at all!!

There are various Storage Options in Android. Files can be stored in internal and external storages. If the CSV file is a static resource, you could think of bundling the file in the "assets" folder of your project.
If you are using the "assets" route, the following code segment can get you a CSVReader.
AssetManager am = getAssets();
AssetFileDescriptor afd = am.openFd ("Motors.csv");
FileDescriptor fd = afd.getFileDescriptor();
readerCSV = new CSVReader(fd, ';','"',0);
The above code snippet doesn't perform error/exception handling, please remember to take care of that. You need to copy the Motors.csv file to the "assets" folder within the project.

Android - reading a text file from Assets seems to include a LOT of junk before/after the actual data?

I package a text file with my Android App (in Assets) which I read within the App itself.
To avoid this file being compressed, it's named 'mytestfile.mp3' and until recently, that worked just fine.
In one of the recent SDK/ADT changes, it seems something 'odd' is happening when reading from Assets and I'm open to ideas as to what it is...
I use code something like this
AssetFileDescriptor descriptor = getAssets().openFd("mytextfile.mp3");
BufferedReader f = new BufferedReader(new FileReader(descriptor.getFileDescriptor()));
String line = f.readLine();
while (line != null) {
// do stuff
Log.d("TAG",line);
}
What I'm now seeing from the Log is rather odd - if the file contained something like this
Fred
Barney
Wilma
I'm seeing huge amounts of nonsense like this in the log
��ߴ�!�c�W���6�f����m�>ߩ���'�����6�#6���l0��mp�
followed - eventually by my text content
Fred
Barney
Wilma
followed by another metric tonne of gibberish - some of which looks like this
����������4�u?'����������������������������������������res/drawable-mdpi/icon.pngPK��������|v?,������������'�����������������������������res/layout-land/dialog_color_picker.xmlPK��������|v?1�!�����t2�������������������������������classes.dexPK��������|v?թVڝ����5���������������������������������META-INF/MANIFEST.MFPK��������|v?�v������j���������������������������������META-INF/CERT.SFPK��������|v?W7#�]�������������������������������������META-INF/CERT.RSAPK������������������������
As you can see, that appears to be raw binary content from the APK (and nothing to do with the text file)??
Is this a recent packaging issue or am I missing something? I'm using ADT15 but I've not tried the recent upgrade just yet!?
p.s. I've upgraded to the latest SDK/ADT and this problem persists - obviously I'd like to escalate it with whoever is at fault (no idea if the problem is Eclipse/ADT/ANT or Android centered) and so I'll start a bounty for ideas...

This is because AssetFileDescriptor.getFileDescriptor() is for your .apk and not the mytextfile.mp3 file inside the .apk. To work with AssetFileDescriptor you need to take e.g. AssetFileDescriptor.getStartOffset() into account as well, which is the offset to the actual file i.e. mytextfile.mp3 in your case.
But there's an easy solution to your problem. Use AssetManager.open(String) instead, which will give you an InputStream to the mytextfile.mp3 file. Like this:
InputStream inputStream = getAssets().open("mytextfile.mp3");
BufferedReader f = new BufferedReader(new InputStreamReader(inputStream));
// ...

Eclipse/ADT occasionally gets the resources corrupted. Try doing a project clean and rebuild to see if that fixes it.

I had the same problem with my app. Try using Apache Commons IO's FileUtils.
This adds another 100kb to your apk, but make File handling much easier.
And if you store the file as myfile.txt instead of .mp3, does it give the same output?
And did you create the file with a Windows or Linux/Unix System? (And with what application?)
/edit: This works for me:
AssetManager am = this.getAssets();
InputStream is = am.open("mytextfile.mp3");
InputStreamReader inputStreamReader = new InputStreamReader(is);
BufferedReader f = new BufferedReader(inputStreamReader);
String line = f.readLine();
while (line != null) {
// do stuff
Log.d("TAG", line);
line = f.readLine();
}

Getting File from /res/raw

I need your help, may be this question is very easy for you.
I have a file in /res/raw folder. For example, it's id is R.raw.myFile. I need to get "File" object. Such as i can do with file on sdcard
File file = new File("/sdcard/myFolder/myFile");
How I can do this?
By the way, sorry for my english if there are some mistakes.
I need "File" object. Not stream.

Use this
InputStream inputStream = getResources().openRawResource(R.raw.filename);

Android Reading Text File Line-by-Line From Res/Raw In Emulator, InvocationException On OpenRawResource

I've found through research on google that that I can read a text file by storing it in my res/raw folder and then accessing it through getResources().openRawResource(R.raw.words);
In a class WordHelper I the constructor provides throws an InvocationException on this line of code:
istream = getResources().openRawResource(R.raw.words);
Which is the one most examples seem to use without a problem, I will then go on to do this
isreader = new InputStreamReader(istream);
myReader = new BufferedReader(isreader);
once everything is working and then use the readLine() method.
All descriptions of InvocationException such as getCause are null, I definately have the file in the res/raw/words.txt.
Thanks for reading.

I got the same problem and solved it using isreader = new InputStreamReader(istream, "UTF8");