Android 后台Service : 向服务器发送心跳包

1. public class HeartbeatService extends Service implements Runnable  

2. {  

3.     private Thread          mThread;  

4.     public int              count           = 0;  

5.     private boolean         isTip           = true;  

6.     private static String   mRestMsg;  

7.     private static String   KEY_REST_MSG    = "KEY_REST_MSG";  

8.   

9.     @Override  

10.     public void run()  

11.     {  

12.         while (true)  

13.         {  

14.             try  

15.             {  

16.                 if (count > 1)  

17.                 {  

18.                     Log.i("@qi", "offline");  

19.                     count = 1;  

20.                     if (isTip)  

21.                     {  

22.                         //判断应用是否在运行  

23.                         ActivityManager am = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);  

24.                         List<RunningTaskInfo> list = am.getRunningTasks(3);  

25.                         for (RunningTaskInfo info : list)  

26.                         {  

27.                             if (info.topActivity.getPackageName().equals("org.yhn.demo"))  

28.                             {  

29.                                 //通知应用，显示提示“连接不到服务器”  

30.                                 Intent intent = new Intent("org.yhn.demo");  

31.                                 intent.putExtra("msg", true);  

32.                                 sendBroadcast(intent);  

33.                                 break;  

34.                             }  

35.                         }  

36.   

37.                         isTip = false;  

38.                     }  

39.                 }  

40.                 if (mRestMsg != "" && mRestMsg != null)  

41.                 {  

42.                     //向服务器发送心跳包  

43.                     sendHeartbeatPackage(mRestMsg);  

44.                     count += 1;  

45.                 }  

46.   

47.                 Thread.sleep(1000 * 3);  

48.             }  

49.             catch (InterruptedException e)  

50.             {  

51.                 e.printStackTrace();  

52.             }  

53.         }  

54.     }  

55.   

56.     private void sendHeartbeatPackage(String msg)  

57.     {  

58.         HttpGet httpGet = new HttpGet(msg);  

59.         DefaultHttpClient httpClient = new DefaultHttpClient();  

60.         // 发送请求  

61.         HttpResponse httpResponse = null;  

62.         try  

63.         {  

64.             httpResponse = httpClient.execute(httpGet);  

65.         }  

66.         catch (Exception e)  

67.         {  

68.             e.printStackTrace();  

69.         }  

70.         if (httpResponse == null)  

71.         {  

72.             return;  

73.         }  

74.   

75.         // 处理返回结果  

76.         final int responseCode = httpResponse.getStatusLine().getStatusCode();  

77.         if (responseCode == HttpStatus.SC_OK)  

78.         {  

79.             //只要服务器有回应就OK  

80.             count = 0;  

81.             isTip = true;  

82.         }  

83.         else  

84.         {  

85.             Log.i("@qi", "responseCode " + responseCode);  

86.         }  

87.   

88.     }  

89.   

90.     @Override  

91.     public IBinder onBind(Intent intent)  

92.     {  

93.         return null;  

94.     }  

95.   

96.   

97.     @Override  

98.     public void onCreate()  

99.     {  

100.         super.onCreate();  

101.     }  

102.   

103.   

104.   

105.     @Override  

106.     public void onDestroy()  

107.     {  

108.         super.onDestroy();  

109.     }  

110.   

111.     public void onStart(Intent intent, int startId)  

112.     {  

113.         Log.i("@qi", "service onStart");  

114.         //从本地读取服务器的URL，如果没有就用传进来的URL  

115.         mRestMsg = getRestMsg();  

116.         if (mRestMsg == null || mRestMsg == "")  

117.         {  

118.             mRestMsg = intent.getExtras().getString("url");  

119.         }  

120.         setRestMsg(mRestMsg);  

121.   

122.         mThread = new Thread(this);  

123.         mThread.start();  

124.         count = 0;  

125.   

126.         super.onStart(intent, startId);  

127.     }  

128.   

129.     public String getRestMsg()  

130.     {  

131.         SharedPreferences prefer = getSharedPreferences("settings.data", Context.MODE_PRIVATE);  

132.         Log.i("@qi", "getRestMsg() " + prefer.getString(KEY_REST_MSG, ""));  

133.         return prefer.getString(KEY_REST_MSG, "");  

134.     }  

135.   

136.     public void setRestMsg(String restMsg)  

137.     {  

138.         SharedPreferences prefer = getSharedPreferences("settings.data", Context.MODE_PRIVATE);  

139.         SharedPreferences.Editor editor = prefer.edit();  

140.         editor.putString(KEY_REST_MSG, restMsg);  

141.         editor.commit();  

142.     }  

143.   

144. }  

启动Service：

[java] view plaincopy

1. Intent serviceIntent = new Intent("HeartbeatService");  

2. serviceIntent.putExtra("url",url);  

3. startService(serviceIntent);  

最后别忘了注册Server和GET_TASKS

[html] view plaincopy

1. <service  

2.             android:name=".demo.HeartbeatService"  

3.             android:label="QServer"  

4.             android:persistent="true" >  

5.             <intent-filter>  

6.                 <action android:name="HeartbeatService" />  

7.             </intent-filter>  

8.         </service>  

[html] view plaincopy

1. <uses-permission android:name="android.permission.GET_TASKS" />  

运行效果：