我怎样才能在检查php后显示android上的通知

I have a php.. Somebody will be login in my application by webview. And android application must check www.website.com/notification.php every 5 seconds.

 if notification php ==> echo 1 ; .. show notification.
 if notification php ==> echo 0 ; .. dont do anything..

I want to check 0 or 1 value by android..

You need to execute your network code in AsynchTask, dedicated thread or IntentService, here is an example code:

Thread networkThread = new Thread() {
   public void run() {
        HttpClient httpclient = new DefaultHttpClient();
        HttpGet httpGet = new HttpGet("http://www.website.com/notification.php");
        HttpResponse response = httpclient.execute(httppost);
        String result = EntityUtils.toString(httpresponse.getEntity());

        if("1".equals(result.trim()){
            showNotification(); // You have to implement this
        }
    }
}
networkThread.start();

Be aware, that making a network request every 5 seconds will drain the battery so quickly, because it will keep the GSM/3G active all the time.