安卓数据保存登录状态

public class loginServe {    public static boolean saveUserInfo(Context context,String username,String password){        try {            File file = new File(context.getFilesDir(),"info.txt");            FileOutputStream fos = new FileOutputStream(file);            fos.write((username+"##"+password).getBytes());            fos.close();            return true;        } catch (Exception e) {            // TODO 自动生成 catch 块            e.printStackTrace();            return false;        }    }    //获取保存的数据    public static Map<String, String> getSaveUserInfo(Context context){        File file = new File(context.getFilesDir(),"info.txt");        try {            FileInputStream fis = new FileInputStream(file);            BufferedReader br = new BufferedReader(new InputStreamReader(fis));            String str = br.readLine();            String[] infos = str.split("##");            Map<String, String> map = new HashMap<String,String>();            map.put("username", infos[0]);            map.put("password", infos[1]);            return map;        } catch (Exception e) {            // TODO 自动生成 catch 块            e.printStackTrace();            return null;        }    }}

这是封装的一个保存数据的类

public class MainActivity extends Activity {   private static final String Tag = "MainActivity";   private EditText et_name;   private EditText et_password;   private CheckBox cb;   @Override   protected void onCreate(Bundle savedInstanceState) {      super.onCreate(savedInstanceState);      setContentView(R.layout.activity_main);      et_name = (EditText) findViewById(R.id.et_name);      et_password = (EditText) findViewById(R.id.et_psw);      cb = (CheckBox) findViewById(R.id.cb_remeber_name);      Map<String, String> map = loginServer.getSaveUserInfo(this);      if(map!=null){         et_name.setText(map.get("username"));         et_password.setText(map.get("password"));      }   }   //登录点击事件    public void login(View view){       String username = et_name.getText().toString().trim();       String password = et_password.getText().toString().trim();       if(TextUtils.isEmpty(username)||TextUtils.isEmpty(password)){          Toast.makeText(this, "用户名或者密码不能为空", Toast.LENGTH_SHORT).show();       }else {          //判断是否保存密码          if (cb.isChecked()) {             //保存用户密码            Log.i(Tag, "需要保存用户名密码");            boolean result = loginServer.saveUserInfo(this,username,password);            if(result){               Toast.makeText(this, "保存数据成功", Toast.LENGTH_SHORT).show();            }         }                //登录            if("wangzhixin".equals(username)&&("123".equals(password))){            Toast.makeText(this, "登录成功", Toast.LENGTH_SHORT).show();         } else{            Toast.makeText(this, "登录失败", Toast.LENGTH_SHORT).show();         }      }    }}