一个android Timer，为何只执行了一次

public void getPaisong() {        final Handler handler = new Handler() {            public void handleMessage(Message msg) {                switch (msg.what) {                case 1: {                    // 初始化搜索模块，注册事件监听                    mSearch = new MKSearch();                    mSearch.init(app.mBMapMan, new MyMKSearchListener());                    jiexi();                    cou++;                    Toast.makeText(                            BMapApiDemoApp.mDemoApp.getApplicationContext(),                            "执行了"+cou+"一次！", Toast.LENGTH_LONG).show();                    }                    break;                }                super.handleMessage(msg);            }        };        TimerTask task = new TimerTask() {            public void run() {                Message message = new Message();                message.what = 1;                handler.sendMessage(message);            }        };        timer = new Timer(true);        timer.schedule(task, 5000); // 延时1000ms后执行，1000ms执行一次        // timer.cancel(); //退出计时器    }