为什么这里使用openFileOutput总是导致程序崩溃

Question

这是代码，按下返回键后没有回到MainActivity，程序直接崩溃了

 public class SecondActivity extends Activity implements OnClickListener{

    private EditText edit;
    private Button button2;

    @Override
    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.second_layout);
        edit = (EditText) findViewById(R.id.edit);
        button2 = (Button) findViewById(R.id.button2);
        button2.setOnClickListener(this);
    }

    public void onClick(View v) {
        switch(v.getId()) {
        case R.id.button2:
            finish();
        }
    }

    protected void onDestroy() {
        super.onDestroy();
        String inputText = edit.getText().toString();
        save(inputText);
    }

    public void save(String inputText) {
        FileOutputStream out = null;
        BufferedWriter writer = null;
        try {
            out = openFileOutput("data", Context.MODE_PRIVATE);
            writer.write(inputText);
        } catch(IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if(writer != null) {
                    writer.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

Answer 1