SharedPreferences轻量级储存

public class MainActivity extends Activity {private TextView tv;     private int time=5;     private Handler handler=new Handler();     @Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);tv = (TextView) findViewById(R.id.tv);    SharedPreferences preferences = getSharedPreferences("b", MODE_PRIVATE);    Editor edit = preferences.edit();      boolean b = preferences.getBoolean("flag", false);    if(b){      Intent intent = new Intent(MainActivity.this,LoginActivity.class);  startActivity(intent);    }else{    edit.putBoolean("flag", true);    edit.commit();new Thread(){public void run() {while (true) {if(time>0){try {sleep(2000);time--;handler.postDelayed(new  Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubtv.setText("倒数"+time+"秒");if(time==0){//跳转LoginActivity  Intent intent = new Intent(MainActivity.this,LoginActivity.class);  startActivity(intent);return;}}}, 1000);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}     }} };        }.start();    }}     }