Android 后台Service : 向服务器发送心跳包

[java] view plaincopyprint?

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 plaincopyprint?

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 plaincopyprint?

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 plaincopyprint?

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

运行效果：

来源：http://blog.csdn.net/vestigge/article/details/8563447