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POandroid FileInputStream crashes
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copied!<p>I am an amateur programmer developing for android. I am just trying get the basics down right now, but I am having an error and I don't know why.</p> <p>I am creating a activity that has a save and a load button, which using the <code>fileOutputStream</code> and <code>fileInputStream</code> to achieve this task.</p> <p>The problem I am having is if I hit the load button the first time I use the activity, my application crashes. Can anyone help me with how to skip the load section if the file hasn't been created yet? What should I use within my if statement. </p> <p>Thanks a ton, here is my code:</p> <pre><code>import android.app.Activity; import android.content.Context; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; public class InternalData extends Activity implements OnClickListener { String FILENAME = "InternalString"; EditText sharedData; TextView dataResults; FileOutputStream fos; String d; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.sharedpreferences); Button save = (Button) findViewById(R.id.bSave); Button load = (Button) findViewById(R.id.bLoad); sharedData = (EditText) findViewById(R.id.etSharedPrefs); dataResults = (TextView) findViewById(R.id.tvLoadSharedPrefs); save.setOnClickListener(this); load.setOnClickListener(this); try { fos = openFileOutput(FILENAME, Context.MODE_PRIVATE); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public void onClick(View v) { // TODO Auto-generated method stub switch (v.getId()) { case R.id.bSave: d = sharedData.getText().toString(); try { fos.write(d.getBytes()); fos.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } break; case R.id.bLoad: FileInputStream fis = null; try { if (openFileInput(FILENAME) != null){ fis = openFileInput(FILENAME); byte[] data = new byte[fis.available()]; while(fis.read(data) != -1){ String readData = new String(data); dataResults.setText(readData); }} } 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(); } } break; } } } </code></pre> <p>Thanks for the help Lukas, I have updated my code, and I was wondering if you could look it over to make sure I am using the AsyncTask properly. Thanks again!</p> <pre><code>public class InternalData extends Activity implements OnClickListener { String FILENAME = "InternalString"; EditText sharedData; TextView dataResults; FileOutputStream fos; String d; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.sharedpreferences); Button save = (Button) findViewById(R.id.bSave); Button load = (Button) findViewById(R.id.bLoad); sharedData = (EditText) findViewById(R.id.etSharedPrefs); dataResults = (TextView) findViewById(R.id.tvLoadSharedPrefs); save.setOnClickListener(this); load.setOnClickListener(this); } public void onClick(View v) { // TODO Auto-generated method stub switch (v.getId()) { case R.id.bSave: d = sharedData.getText().toString(); try { fos = openFileOutput(FILENAME, Context.MODE_PRIVATE); fos.write(d.getBytes()); fos.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } break; case R.id.bLoad: AsyncTask<String, Integer, String> dat = new loadInternalData().execute(FILENAME); break; } } public class loadInternalData extends AsyncTask<String, Integer, String> { @Override protected String doInBackground(String... params) { // TODO Auto-generated method stub FileInputStream fis = null; String collected = null; try { fis = openFileInput(FILENAME); byte[] data = new byte[fis.available()]; while (fis.read(data) != -1){ collected = new String(data); } } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ try { fis.close(); return collected; } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return collected; } @Override protected void onPostExecute( String result ) { super.onPostExecute(result); Log.i( "InteralStorage", "onPostExecute(): " + result ); dataResults.setText( result ); } } </code></pre> <p>}</p>

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