Save Instance State if device is rotated

try {
		String MYFILE = "my_file";
		String strText = "My text";

                // MODE_APPEND, MODE_WORLD_READABLE, MODE_WORLD_WRITEABLE
		// create new file or rewrite existing
                FileOutputStream fos = openFileOutput(MYFILE, getApplicationContext().MODE_PRIVATE);
                // append to file
                FileOutputStream fos = openFileOutput(MYFILE, getApplicationContext().MODE_APPEND);

		fos.write(strText.getBytes());
		fos.close();					
	} catch (IOException e) {
		e.toString();
    }	

try {
// new file    
BufferedWriter out = new BufferedWriter(
    		new FileWriter("outfilename"));
    // append text 
   BufferedWriter out = new BufferedWriter(new FileWriter("outfilename", true));
    out.write("some text");
    out.close();
 } catch (IOException e) {
   e.toString();
}			

EditText hEditText;

// TextChanged in onCreate

hEditText = (EditText)findViewById(R.id.idEditText);

hEditText.addTextChangedListener(new TextWatcher() {

	public void afterTextChanged(Editable str) {

	}



	public void beforeTextChanged(CharSequence s, int start, int count,

			int after) {

	}



	public void onTextChanged(CharSequence sq, int start, int before,

			int count) {

	}

});

public class MainActivity extends Activity {
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	private static class SampleView extends View {

		// CONSTRUCTOR
		public SampleView(Context context) {
			super(context);
			setFocusable(true);

		}
	       private static void makePath(Path p) {
	            p.moveTo(10, 0);
	            p.cubicTo(100, -50, 200, 150, 300, 0);
	        }
		@Override
		protected void onDraw(Canvas canvas) {

			canvas.drawColor(Color.CYAN);
			Paint p = new Paint();
			// smooths
			p.setAntiAlias(true);
			p.setColor(Color.RED);
			p.setStyle(Paint.Style.STROKE); 
			p.setStrokeWidth(5);
			// opacity
			//p.setAlpha(0x80);
 
			p.setColor(Color.BLACK);
			Path mPath = new Path();
            makePath(mPath);
			canvas.drawPath(mPath, p); //(rectF, 90, 45, true, p);
		}

	}
}

    <LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
		android:orientation="vertical"
			android:gravity="top"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" >

        <ScrollView
            android:id="@+id/scrollView1"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" >

            <HorizontalScrollView
                android:id="@+id/horizontalScrollView1"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" >

 
            <LinearLayout
			    android:gravity="top"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content" >

                <ImageView
                    android:id="@+id/imageViewObrazekGeometrie"
                    android:layout_width="360dp"
                    android:layout_height="777dp"
                    android:src="@drawable/geometrie_vzorecky" />

            </LinearLayout>
            </HorizontalScrollView>
        </ScrollView>

    </LinearLayout>