三秒变换标题

Handler handler = new Handler() {    @Override    public void handleMessage(Message msg) {        String str = (String) msg.obj;        tv.setText(str);    }};private Myadapter m;@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    tv = (TextView) findViewById(R.id.tv);    lv = (ListView) findViewById(R.id.lv);    m = new Myadapter();    lv.setAdapter(m);    new Myasny().execute(urlstr);    new Thread() {        private List<book.DataBean> data;        private String news_title;        @Override        public void run() {            String settext = Dao.Settext(str);            Gson g = new Gson();            final book bo = g.fromJson(settext, book.class);            data = bo.getData();            Timer t = new Timer();            TimerTask tt = new TimerTask() {                int i = 0;                @Override                public void run() {                    if (i <= data.size() - 1) {                        Message message = handler.obtainMessage();                        news_title = data.get(i).getNews_title();                        message.obj = news_title;                        handler.sendMessage(message);                        i++;                    } else if (i == data.size()) {                        i = 0;                        Message message = handler.obtainMessage();                        news_title = data.get(i).getNews_title();                        message.obj = news_title;                        handler.sendMessage(message);                        i++;                    }                }            };            t.schedule(tt, 0, 3000);        }    }.start();