Develop Reference

How can I write a public file for my service to pick up on Android?

I have two parts to this question: 1) what is the best solution to my need, and 2) how do I do this?
1) I have a client app which sends bundles to a service app. the bundles can break the limit on bundle size, so I need to write the actual request out and read it in on the service side. Because of this, I can't write to my private internal storage. I've used these pages heavily, and haven't had luck: http://developer.android.com/guide/topics/data/data-storage.html
http://developer.android.com/training/basics/data-storage/files.html
My current understanding is that my best path is to use this to get a public dir:
File innerDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
I then add in my filename:
String fileName = String.valueOf(request.timestamp + "_avoidRoute"+count+++".ggr");
Combing these two results in the full file path:
/storage/emulated/0/Download/GroundGuidance/Route/1425579692169_avoidRoute1.ggr
Which I write to disk like this:
fos = context.openFileOutput(fullPath, Context.MODE_WORLD_WRITEABLE);
fos.write(routeString.getBytes());
fos.close();
When I try to write this to disk I get the error
java.lang.IllegalArgumentException: File /storage/emulated/0/Download/GroundGuidance/Route/1425579692169_avoidRoute1.ggr contains a path separator
Of course it does - I need it to have a path. I've searched online for solutions to this error which tell me to us FileOutputStream to write a full path. I did, but while my app doesn't error and appears to create the file, I'm also not able to view it on my phone in Windows Explorer, leading me to believe that it is creating a file with private permissions. So this brings me to my post and two questions:
1) Is there a different approach I should be trying to take to share large amounts of data between my client and service apps?
2) If not, what am I missing?
Thanks all for reading and trying to help!

Combing these two results in the full file path:
/storage/emulated/0/Download/GroundGuidance/Route/1425579692169_avoidRoute1.ggr
Which I write to disk like this:
fos = context.openFileOutput(fullPath, Context.MODE_WORLD_WRITEABLE);
This is not an appropriate use of Context's openFileOutput() method as that does not take a full path, but rather a filename within an app's private storage area.
If you are going to develop a full path yourself, as you have, then use
fos = new FileOutputStream(fullPath)
The Sharing permission setting is not applicable to the External Storage, though you will need a manifest permission to write (and implicitly read) on your creator, and the one for reading on your consumer.
Or, instead of constructing a full path, you could use your private storage with a filename and Context.MODE_WORLD_WRITEABLE (despite the being deprecated as an advisory) and pass the absolute path of the result to the other app to use with new FileInputStream(path).
Or you could use any of the other data interchange methods - content providers, local sockets, etc.

Outputting a txt file to a folder in internal memory in android

I am in need to create a text file where the input is taken from the user.
I am trying to save the txt file in a folder(folder should be created even if it is not there)
My code is as follows,
FileOutputStream fileos = null;
if (FreeMemory() != 0) {
FileOutputStream fos=null;
try {
File path=new File(getFilesDir(),"sri");
if(!path.exists()){
path.mkdir();
}
File mypath=new File(path,"myfile.txt");
if (!mypath.exists()) {
fos = new FileOutputStream( mypath);
String text="Write Hii";
fos.write(text.getBytes());
fos.close();
}
}catch(Exception e){
}
}
The "path" variable gives this path: "/data/data/com.example.gm/files/sri"
I navigated to this path in my device: Android-->Data-->com.example.gm-->files-->
but the folder "sri" is not created and even the file also. Am I navigating to th ecorrect path ? I am not able to find out the file in the device.
I searched for the folder by installing "Astro File Manager" app too. But, couldn't find it. I am not getting any Exception when writing to the folder. The code must be correct. But where is the folder and file? Please anyone help me in solving this.
I want to save the txt file in internal memory of my device.
Whats wrong with my code? Please suggest me the solution.
I have gone through many trails and finally approached stackoverflow.
Thanks for any help!!

The data in the internal storage is not accessible out side the application owning it, so any third party application like file browser or Astro File Manager will not be able to see the files. The application with root access will only be able to access the files in the internal memory. I believe you should programmatically verify if the file is created. getFilesDir() will give the internal memory location allocated to that app.

Have you give the permission in manifiest file
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

ANDROID internal storage file delete/exist not working for me

First of all, I want to know if making a file without extension is okay. For example, making a file with ".txt" extendsion will make it a txt file on a computer, but I don't know it matters in android. And I noticed that when working on eclipse, I could deleted a fild with the extensions but couldn't delete a file without a extension.
I want my program to delete a file in the internal storage (com.name.application folder) but it's not working for me.
I make a file with
FileOutputStream fos = openFileOutput(FileName, MODE_PRIVATE);
write with
bos = new BufferedOutpuStream(openFileOutput(FileName,Context.MODE_APPEND)
bos.write(newVocabFile.getBytes());
and I want to delete with
FILE file = new File(fileName);
fild.delete();
I did researches on google and applied different methods to my codes, but every method did not work for me. Because .delete() does not work properly, .exist() does not work either. I tired making the mile with and without extension but both ways did not work either.
I really need to get through this in order to finish my application. Please help me

You have a typo on this line
FILE file = new File(fileName);
fild.delete();
It should be
File file = new File(fileName);
file.delete();

Get preloaded file in android

I'm new to android development and I am working on a little project. What I am having some issue with is getting access to preloaded files.
In my app, I have an XML file that I preloaded (I just simply put it in my src folder in a package). How do I access them in my classes? I need to get a File object pointing to this file so that I can use it as I would I/O files. It seems like this should be trivial, but alas I am stuck.
Lets say the file is located under: com.app.preloadedFiles/file1.XML
I've tried something along the lines of this, but have had no success:
URL dir_url = ClassLoader.getSystemResource("preloadedFiles/file1.XML");
FIle file = new File(dir_url.toURI());

I solved this in my app by getting an InputStream to the file -- something like:
myContext.getAssets().open(fileName);
//read the data and store it in a variable
Then, if you truly need to do File related opterations with it, you can write it to a private (or public) directory and do your operations from you newly written file. Something like:
File storageDir = myContext.getDir(directoryName, Context.MODE_PRIVATE);
File myFile = new File(storageDir + File.separator + fileName);
//then, write the data to the file and manipulate it -- store the name for access via File later

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(...).