stuart-d2
3/23/2014 - 5:53 PM

Writing to a File On Device Uses read and write methods to a file, also uses BufferedReader & BufferedWriter Opens a private file for writin

Writing to a File On Device Uses read and write methods to a file, also uses BufferedReader & BufferedWriter Opens a private file for writing, creates that file,
Checks whether file exists, if yes opens it, if no creates that file Text is red from file and displayed

ReadWriteToFileOnDevice
content_copyfile_download
package course.examples.DataManagement.FileInternal;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.LinearLayout;
import android.widget.TextView;
import course.examples.Files.FileWriteAndRead.R;

//Extend Activity
public class InternalFileWriteReadActivity extends Activity {

//String fileName is the writeable file the system looks for and opens
//If does not exists, it creates
	private final static String fileName = "TestFile.txt";
	private String TAG = "InternalFileWriteReadActivity";

	@Override
	public void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		setContentView(R.layout.main);
//LinearLayout created that will be later passed into the readFile m() to display the text
		LinearLayout ll = (LinearLayout) findViewById(R.id.linearLayout);

		// Check whether fileName already exists in directory used
		// by the openFileOutput() method.
		// If the text file doesn't exist, then create it now
		
		if (!getFileStreamPath(fileName).exists()) {

			try {

				writeFile();

			} catch (FileNotFoundException e) {
				Log.i(TAG, "FileNotFoundException");
			}
		}

		
		// Read the data from the text file and display it
		try {
			
			readFile(ll);

		} catch (IOException e) {
			Log.i(TAG, "IOException");
		}
	}

	private void writeFile() throws FileNotFoundException {

		FileOutputStream fos = openFileOutput(fileName, MODE_PRIVATE);

		PrintWriter pw = new PrintWriter(new BufferedWriter(
				new OutputStreamWriter(fos)));

		pw.println("Line 1: This is a test of the File Writing API");
		pw.println("Line 2: This is a test of the File Writing API");
		pw.println("Line 3: This is a test of the File Writing API");

		pw.close();

	}

	private void readFile(LinearLayout ll) throws IOException {

		FileInputStream fis = openFileInput(fileName);
		BufferedReader br = new BufferedReader(new InputStreamReader(fis));

		String line = "";

		while (null != (line = br.readLine())) {

			TextView tv = new TextView(this);
			tv.setTextSize(24);
			tv.setText(line);

			ll.addView(tv);

		}

		br.close();

	}

}

=======================================================================
// XML linear layout 
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/scrollView1"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <LinearLayout
        android:id="@+id/linearLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical" >
    </LinearLayout>

</ScrollView>