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Read a file, if it doesn't exist then create

Honestly, I've searched a lot do this task so I ended up trying various methods but nothing worked until I ended up on this code. It works for me perfectly like it should, so I do not want to change my code.
The help I need is to put this code in a such a way that it begins to read a file, but if it the file doesn't exist then it will create a new file.
Code for saving data:
String data = sharedData.getText().toString();
try {
fos = openFileOutput(FILENAME, MODE_PRIVATE);
fos.write(data.getBytes());
fos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Code for loading data:
FileInputStream fis = null;
String collected = null;
try {
fis = openFileInput(FILENAME);
byte[] dataArray = new byte [fis.available()];
while (fis.read(dataArray) != -1){
collected = new String(dataArray);
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
try {
fis.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
So If I add the saving data code in to the "FileNotFoundException" catch of the loading data part then could I achieve what I want?

Add
File file = new File(FILENAME);
if(!file.exists())
{
file.createNewFile()
// write code for saving data to the file
}
above
fis = openFileInput(FILENAME);
This will check if there exists a File for the given FILENAME and if it doesn't it will create a new one.

If you're working on Android, why don't you use the API's solution for saving files?
Quoting:
String filename = "myfile";
String string = "Hello world!";
FileOutputStream outputStream;
try {
outputStream = openFileOutput(filename, Context.MODE_PRIVATE);
outputStream.write(string.getBytes());
outputStream.close();
} catch (Exception e) {
e.printStackTrace();
}
You should really read the whole document, they explain pretty well the basic ways of creating or accessing files, you can also check the different ways of storing data.
But regarding your original question:
So If I add the saving data code in to the "FileNotFoundException"
catch of the loading data part then could I achieve what I want?
Yes, you could achieve it.

Try this one:
public static void readData() throws IOException
{
File file = new File(path, filename);
if (!file.isFile() && !file.createNewFile()){
throw new IOException("Error creating new file: " + file.getAbsolutePath());
}
BufferedReader r = new BufferedReader(new FileReader(file));
try {
// ...
// read data
// ...
}finally{
r.close();
}
}
Ref: Java read a file, if it doesn't exist create it

How can I write into text file for android application?

I want to write some information about users to reuse them but I cannot create a text file so I cannot read it, too. Before starting to read, I want to accomplish writing to text file.
I wrote the user permission into manifest file.
Also, my code for writing into text file as in below:
public static void writeFile(String item, String fileName) throws IOException {
BufferedWriter out;
try {
FileWriter fileWriter= new FileWriter(Environment.getExternalStorageDirectory().getPath()+"/"+fileName);
out = new BufferedWriter(fileWriter);
out.write(item);
out.close();
}catch (FileNotFoundException e) {
e.printStackTrace();
}catch (IOException e) {
e.printStackTrace();
}
}
So can anyone say the problem? Thank you.

As far I understood, you may want to use sharedpreferences, take a look: Simple Example Sharedpreferences
You can store and retrieve data easily...
Anyway...
Make sure your manifest contains:
1. android:name="android.permission.READ_EXTERNAL_STORAGE
2. android:name="android.permission.WRITE_EXTERNAL_STORAGE
String string1 = "Hey you";
FileOutputStream fos ;
try {
fos = new FileOutputStream("/sdcard/filename.txt", true);
FileWriter fWriter;
try {
fWriter = new FileWriter(fos.getFD());
fWriter.write("hi");
fWriter.close();
} catch (Exception e) {
e.printStackTrace();
} finally {
fos.getFD().sync();
fos.close();
}
} catch (Exception e) {
e.printStackTrace();
}

How to write to a textfile in one Activity & read that file in another Activity?

I am able to write and then read a text file in the SAME activity, but I am unable to read a text file after writing to it from another Activity.
Ex: Activity A creates and writes to a text file. Activity B reads that text file.
I use this code to write to the text file in Activity A:
FileOutputStream fos = null;
OutputStreamWriter osw = null;
try
{
fos = openFileOutput("user_info.txt", Context.MODE_WORLD_WRITEABLE);
osw = new OutputStreamWriter(fos);
osw.write("text here");
osw.close();
fos.close();
}
catch (FileNotFoundException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
And then I use this code to try and read the same text file created by Activity A, but I get a FileNotFoundException:
try
{
FileInputStream fis = openFileInput("user_info.txt");
InputStreamReader isr = new InputStreamReader(fis);
BufferedReader buff = new BufferedReader(isr);
String line;
while((line = buff.readLine()) != null)
{
Toast.makeText(this, line, Toast.LENGTH_LONG).show();
}
}
catch (FileNotFoundException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
Does anyone know why I am getting the FileNotFoundException?
Is it a path issue?

Don't really know how is built your application, but, the error you get does seem like a path issue, are you sure both Activities are in the same folder ?
If not, you'll need to set either an abolute path (like : "/home/user/text.txt") for the text file or a relative path (like : "../text.txt").
If you're not sure, try to print the current path for the Activity using some command like
new File(".").getAbsolutePath();
And, although I can't say I'm expert with Android, are you sure you need the Context.MODE_WORLD_WRITEABLE for your file ? If no other application than yours is reading or writing from/to it, it should not be necessary, right ?

it is surealy a path issue.
you can write like this
fpath=Environment.getExternalStorageDirectory().getAbsolutePath()+"/"+"yourdirectory";
File custdir=new File(fpath);
if(!custdir.exists())
{
custdir.mkdirs();
}
File savedir=new File(custdir.getAbsolutePath());
File file = new File(savedir, filename);
if(file.exists())
{
file.delete();
}
FileOutputStream fos;
byte[] data = texttosave.getBytes();
try {
fos = new FileOutputStream(file);
fos.write(data);
fos.flush();
fos.close();
Toast.makeText(getBaseContext(), "File Saved", Toast.LENGTH_LONG).show();
finish();
} catch (FileNotFoundException e) {
Toast.makeText(getBaseContext(), "Error File Not Found", Toast.LENGTH_LONG).show();
Log.e("fnf", ""+e.getMessage());
// handle exception
} catch (IOException e) {
// handle exception
Toast.makeText(getBaseContext(), "Error IO Exception", Toast.LENGTH_LONG).show();
}
and you can read like
String locatefile=Environment.getExternalStorageDirectory().getAbsolutePath()+"/"+"yourdirectory"+"/filename";
try {
br=new BufferedReader(new FileReader(locatefile));
while((text=br.readLine())!=null)
{
body.append(text);
body.append("\n");
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

Reading my Serialized Object from File in Android

This is my first attempt at serializing/deserializing objects on any platform and, to put it mildly, I'm confused.
After implementing Serializable to my game object I output it to a file thus:
public void saveGameState(){
ByteArrayOutputStream bos = new ByteArrayOutputStream();
try {
ObjectOutput out = new ObjectOutputStream(bos);
out.writeObject(theGame);//theGame is an instance of the custom class
//TGame which stores game info.
byte[] buf = bos.toByteArray();
FileOutputStream fos = this.openFileOutput(filename,
Context.MODE_PRIVATE);
fos.write(buf);
fos.close();
} catch(IOException ioe) {
Log.e("serializeObject", "error", ioe);
}
File f =this.getDir(filename, 0);
Log.v("FILE",f.getName());
}
This seems to work, in that I get no exceptions raised. I can only know for sure when I deserialize it. Which is where things go pear shaped.
public God loadSavedGame(){
TGame g=null;
InputStream instream = null;
try {
instream = openFileInput(filename);
} catch (FileNotFoundException e) {
e.printStackTrace();
return null;
}
try {
ObjectInputStream ois = new ObjectInputStream(instream);
try {
g= (TGame) ois.readObject();
return g;
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return null;
}
} catch (StreamCorruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return null;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return null;
}
}
I got the basis of this code from here Android Java -- Deserializing a file on the Android platform and tried to modify it for my app. When running I get
05-31 23:30:45.493: ERROR/copybit(1279): copyBits failed (Invalid argument)
When the output should be loaded and the saved game start up from when it was saved.
Any help would be appreciated.

The error you've shown is not at all related to serialization: its actually a video display error. I'd suggest looking at the object BEFORE you serialize to make sure its not null, and I'd also suggest serializing to a file on the SD card to make sure you actually had data output (so use new FileOutputStream("/mnt/sdcard/serializationtest") as the output stream and new FileInputStream("/mnt/sdcard/serializationtest") as the input stream) while you are debugging; you can switch back to the context methods after it works, but make sure your sdcard is plugged in while you are doing this.
Finally, modify your logging to look like this:
try {
ObjectInputStream ois = new ObjectInputStream(instream);
try {
g= (TGame) ois.readObject();
return g;
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
android.util.Log.e("DESERIALIZATION FAILED (CLASS NOT FOUND):"+e.getMessage(), e);
e.printStackTrace();
return null;
}
} catch (StreamCorruptedException e) {
android.util.Log.e("DESERIALIZATION FAILED (CORRUPT):"+e.getMessage(), e);
// TODO Auto-generated catch block
e.printStackTrace();
return null;
} catch (IOException e) {
android.util.Log.e("DESERIALIZATION FAILED (IO EXCEPTION):"+e.getMessage(), e);
// TODO Auto-generated catch block
e.printStackTrace();
return null;
}
and see what error gets returned. I expect the serialization is failing somehow.

To seralize or deserialize anything you can use SIMPLE api. It is very easy to use. Download the file and use it in your program
Have a look here
http://simple.sourceforge.net/download/stream/doc/tutorial/tutorial.php#deserialize
Thanks Deepak

I have created below class to do the save and retrieve object.
public class SerializeUtil {
public static <T extends Serializable> void saveObjectToFile(Context context, T object, String fileName){
try {
FileOutputStream fos = context.openFileOutput(fileName, Context.MODE_PRIVATE);
ObjectOutputStream os = new ObjectOutputStream(fos);
os.writeObject(object);
os.close();
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
public static<T extends Serializable> T getObjectFromFile(Context context, String fileName){
T object = null;
try {
FileInputStream fis = context.openFileInput(fileName);
ObjectInputStream is = new ObjectInputStream(fis);
object = (T) is.readObject();
is.close();
fis.close();
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
return object;
}
public static void removeSerializable(Context context, String filename) {
context.deleteFile(filename);
}
}

save more than one pic with different names in sdcard

Im doing a program where u can draw your signature on the phone. Right now it saves one image but I would like to save more than one image since there are more than one customer that needs to sign their package. very thankful for any kind of help.
public void save() {
File sdImageMainDirectory = new File("/sdcard/mySignatures");
sdImageMainDirectory.mkdirs();
String nameFile = "newpic";
FileOutputStream out = null;
try {
out = new FileOutputStream(sdImageMainDirectory.toString() +"/" + nameFile + ".jpg");
mBitmap.compress(Bitmap.CompressFormat.JPEG, 100, out);
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
out.flush();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
out.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
out=null;
}

Rather obviously, you need to change the filename to something unique for each one. Numbering them sequentially would work. Or you let the user enter a name, and validate it for legality.