CODEWITHSUNDEEP
javaandroiddatabasetextsavestate
Niamh Doyle
Niamh Doyle

Reputation: 1949

How to write to and read from a text file in Android?

I'm developing a Dictionary app. There is a Favourite button on the app that allows users to:

So far, I have coded as follows:

UPDATED CODE:

//Writing lines to myFavourite.txt
    btnAddFavourite = (ImageButton) findViewById(R.id.btnAddFavourite);
    btnAddFavourite.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // Writing the content
                try {
                // opening myFavourite.txt for writing
                  OutputStreamWriter out = new OutputStreamWriter(openFileOutput("myFavourite.txt", MODE_APPEND));
                // writing the ID of the added word to the file
                  out.write(mCurrentWord);  
                // closing the file
                  out.close();
                } catch (java.io.IOException e) {
                  //doing something if an IOException occurs.
                }
                Toast toast = Toast.makeText(ContentView.this, R.string.messageWordAddedToFarvourite, Toast.LENGTH_SHORT);
                toast.show();
            }
        });

    //Reading lines from myFavourite.txt
    btnAddFavourite.setOnLongClickListener(new View.OnLongClickListener() {         

            @Override
            public boolean onLongClick(View v) {

             //trying opening the myFavourite.txt
               try {
             // opening the file for reading
                InputStream instream = openFileInput("myFavourite.txt");

             // if file the available for reading
                if (instream != null) {
            // prepare the file for reading
                InputStreamReader inputreader = new InputStreamReader(instream);
                BufferedReader buffreader = new BufferedReader(inputreader);

            String line;

            // reading every line of the file into the line-variable, on line at the time
            try {
                while ((line = buffreader.readLine()) != null) {
                  // do something with the settings from the file
                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

          }

          // closing the file again
          try {
            instream.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        } catch (java.io.FileNotFoundException e) {

          // ding something if the myFavourite.txt does not exits
        }
        return false;

        }});
        }

However, the Favourite button does not work with the above code lines.

The file myFavourite.txt does exits (in data/data/my_project/files in Eclipse) but it only contains one recently added word. Furthermore, the app is force-closed when the Favourite button is long-clicked.

What have I been doing wrong? I am very grateful if you guys can help me solve this problem. Thank you very much.

========

EDIT

Thank you very much for your help. I updated my code to reflect your comments and prompts. By now, there have been some improvements: The Favourite words have been written to the file myFavourite.txt like word2 word2 word3... (though I want them to appear in new lines).

However, the Favourite list is still not loaded when the Favourite button is long-clicked.

In fact, my purpose is to make it possible to load the Favourite list inside the app and allow users to choose the word(s) to look up again.

Many thanks for your help.

Upvotes: 1

Views: 3393

Answers (2)

Horrorgoogle
Horrorgoogle

Reputation: 7868

Look this example which is simple to read text file in android.

Example

file must be kept in.

res/raw/ myFavourite.txt .

Same as your problem. How can I read a text file from the SD card in Android?

Another simple tutorial.How to read text file. http://android-er.blogspot.com/2010/07/display-text-file-in-resraw_01.html

Upvotes: 0

Anton Hansson
Anton Hansson

Reputation: 2171

On this line

OutputStreamWriter out = new OutputStreamWriter(openFileOutput("myFavourite.txt",0));

You are overwriting the file if it already exists every time you create the stream. What you want to do is to to pass MODE_APPEND instead of 0. Have a look at the documentation.

Regarding the long clicks, these lines

if (instream) {

and

while (( line = buffreader.readLine())) {

Shouldn't even compile. What you want is probably something like

if (instream.ready()) {

and

while ((line = buffreader.readLine()) != null) {
    // Use this line
}

Upvotes: 1

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