android - 我怎样才能保持每 5 秒请求一次页面而不耗尽电池电量？

Question

我正在开发的 android 应用程序需要每 5 秒在我的服务器上请求一个页面，但我担心这会消耗大量电池，有没有更简单的方法？我目前的方法是每 5 秒循环一次的服务:

protected void onHandleIntent(Intent intent) {
      while (true){

          long endTime = System.currentTimeMillis() + 5*1000;
          while (System.currentTimeMillis() < endTime) {
              synchronized (this) {
                  try {
                      wait(endTime - System.currentTimeMillis());


                    HttpClient httpclient = new DefaultHttpClient();
                    HttpPost httppost = new HttpPost("http://www.***.***/***/request_sms.php");
                    String HTML = "";
                    try {
                        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
                        nameValuePairs.add(new BasicNameValuePair("id", "1"));
                        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

                        HttpResponse response = httpclient.execute(httppost);
                        HTML = EntityUtils.toString(response.getEntity());
                    } catch (ClientProtocolException e) {} catch (IOException e) {} 


                        if(HTML.indexOf("[NO TEXTS]") > 0) {
                        } else {
                            Vector<String> all_sms = getBetweenAll(HTML, "<sms>", "<sms>");
                            for(int i = 0, size = all_sms.size(); i < size; i++) {
                                String from = getBetween(all_sms.get(i), "<from>", "</from>");
                                String to = getBetween(all_sms.get(i), "<to>", "</to>");
                                String msg = getBetween(all_sms.get(i), "<msg>", "</msg>");
                                String sent = getBetween(all_sms.get(i), "<sent>", "</sent>");
                                String HTML1 = "";
                                HttpClient httpclient1 = new DefaultHttpClient();
                                HttpPost httppost1 = new HttpPost("http://www.***.***/***/add_sms.php");
                                try {
                                    List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
                                    nameValuePairs.add(new BasicNameValuePair("from", from));
                                    nameValuePairs.add(new BasicNameValuePair("to", to));
                                    nameValuePairs.add(new BasicNameValuePair("msg", msg));
                                    nameValuePairs.add(new BasicNameValuePair("sent", sent));
                                    httppost1.setEntity(new UrlEncodedFormEntity(nameValuePairs));

                                    HttpResponse response1 = httpclient1.execute(httppost1);
                                    HTML1 = EntityUtils.toString(response1.getEntity());
                                    HN.post(new DisplayToast(HTML1)); 
                                } catch (ClientProtocolException e) {} catch (IOException e) {} 

                            }
                        }


                      } catch (Exception e) {
                  }
              }
          }

        }


  }

Answer 1

为什么需要每 5 秒检查一次？您最好让服务器向设备推送通知(通过 c2dm)，告知何时有更新可用。如果您持续轮询服务器，无论您如何实现，都会耗尽电池电量。