Brauche Hilfe beim Programmieren: Textdatei von der Sd Karte auslesen und im TextView anzeigen

1public class MainActivity extends Activity {
2 private TextView mTextInput;
3 private File f;
4 private Button mButton;
5
6 @Override
7 public void onCreate(Bundle savedInstanceState) {
8 super.onCreate(savedInstanceState);
9 setContentView(R.layout.main);
10
11 mTextInput = (TextView) findViewById(R.id.textRead);
12
13 f = new File(Environment.getExternalStorageDirectory()+"/test.txt");
14
15 mButton = (Button) findViewById(R.id.data_load);
16 mButton.setEnabled(f.exists());
17 }
18 public void onButtonClick (View view) {
19 switch (view.getId()) {
20 case R.id.data_load:
21 try {
22 FileInputStream fileIn =
23 new FileInputStream(f);
24 loadData(fileIn);
25
26 } catch (FileNotFoundException e) {
27 e.printStackTrace();
28 }
29 break;
30 }
31 }
32 private void loadData(FileInputStream fileIn) {
33 BufferedReader fileInBuffer = new BufferedReader (new InputStreamReader(fileIn));
34 String text = "";
35 String line;
36 try {
37 while ((line = fileInBuffer.readLine()) != null) {
38 text += line;
39 }
40 } catch (IOException e) {
41 e.printStackTrace();
42 } finally {
43 try {
44 fileInBuffer.close();
45 } catch (IOException e) {
46 e.printStackTrace();
47 }
48 }
49 mTextInput.setText(text);
50 }
51}

1<Button
2 android:id="@+id/data_load"
3 android:layout_width="100dp"
4 android:layout_height="wrap_content"
5 android:layout_gravity="center_horizontal"
6 android:text="@string/load" />

1<Button
2 android:onClick="compassStart"
3 android:id="@+id/data_load"
4 android:layout_width="100dp"
5 android:layout_height="wrap_content"
6 android:onClick="loadStart"
7 android:layout_gravity="center_horizontal"
8 android:text="@string/load" />

1public void loadStart(final View View) {
2 try {
3 FileInputStream fileIn =
4 new FileInputStream(f);
5 loadData(fileIn);
6 } catch (FileNotFoundException e) {
7 e.printStackTrace();
8 }
9 break;
10 }

1public void loadStart(final View View) {
2 FileInputStream fileIn;
3 try {
4 fileIn = new FileInputStream(f);
5 loadData(fileIn);
6 } catch (FileNotFoundException e) {
7 e.printStackTrace();
8 }
9 }
10 private void loadData(FileInputStream fileIn) {
11 BufferedReader fileInBuffer = new BufferedReader (new InputStreamReader(fileIn));
12 String text = "";
13 String line;
14 try {
15 while ((line = fileInBuffer.readLine()) != null) {
16 text += line;
17 }
18 } catch (IOException e) {
19 e.printStackTrace();
20 } finally {
21 try {
22 fileInBuffer.close();
23 } catch (IOException e) {
24 e.printStackTrace();
25 }
26 }
27 mTextInput.setText(text);
28}
29}