Android C2DM学习——云端推送

女爷i 2023-10-10 11:08 7阅读 0赞

## 一．基础知识 ##

当我们开发需要和服务器交互的应用程序时，基本上都需要获取服务器端的数据，比如《地震及时通》就需要及时获取服务器上最新的地震信息。要获取服务器上不定时更新的信息一般来说有两种方法，第一种是客户端使用Pull（拉）的方式，隔一段时间就去服务器上获取信息，看是否有更新的信息出现。第二种就是服务器使用Push（推送）的方式，当服务器端有新信息了，则把最新的信息Push到客户端上。

虽然Pull和Push两种方式都能实现获取服务器端更新信息的功能，但是明显来说Push is better than pull。因为Pull方式更费客户端的网络流量，更主要的是费电量。

Android从2.2版本开始增加了Cloud to Device Messaging（[C2DM][]）框架，在系统中支持了Push功能，基于Android平台使用Push功能更加简单了。虽然C2DM目前还处在实验室阶段，不过小规模的使用应该没问题

下面我们就来体验一下Android的C2DM功能。

## 二．C2DM框架 ##

使用Android的C2DM功能有几个要求：

1. 需要Android2.2及以上的系统版本。

2. 使用C2DM功能的Android设备上需要设置好Google的账户。

3. 需要在[这里][Link 1]注册使用C2DM功能的用户邮箱账号（最好为C2DM单独注册一个Gmail邮箱账号）。

我们接下来C2DM的一个完整过程，这里借用一下Google官方推出的Chrome To Phone过程图来说明下。

![0_1310033311Jzf9.gif][]

图1 C2DM操作过程图

要使用C2DM来进行Push操作，基本上要使用以下6个步骤：

（1）注册：Android设备把使用C2DM功能的用户账户（比如android.c2dm.demo@gmail.com）和App名称发送给C2DM服务器。

（2）C2DM服务器会返回一个registration\_id值给Android设备，设备需要保存这个registration\_id值。

（3）Android设备把获得的registration\_id和C2DM功能的用户账户（android.c2dm.demo@gmail.com）发送给自己的服务器，不过一般用户账户信息因为和服务器确定好的，所以不必发送。

这样Android设备就完成了C2DM功能的注册过程，接下来就可以接收C2DM服务器Push过来的消息了。

（4）服务器获得数据。这里图中的例子Chrome To Phone，服务器接收到Chrome浏览器发送的数据。数据也可以是服务器本地产生的。这里的服务器是Google AppEngine（很好的一项服务，可惜在国内被屏了），要换成自己的服务器。服务器还要获取注册使用C2DM功能的用户账户（android.c2dm.demo@gmail.com）的ClientLogin权限Auth。

（5）服务器把要发送的数据和registration\_id一起，并且头部带上获取的Auth，使用POST的方式发送给C2DM服务器。

（6）C2DM服务器会以Push的方式把数据发送给对应的Android设备，Android设备只要在程序中按之前和服务器商量好的格式从对应的key中获取数据即可。

这样我们就大概明白了C2DM的工作流程，下面我们就结合一个实例来具体的说明以上6个步骤。

## 三．实例开发 ##

我们要创建的程序名称为AndroidC2DMDemo，包名为com.ichliebephone.c2dm。

开始之前我们先去C2DM网页上注册一下使用C2DM功能的用户账户。

![0_1310033516Nnpp.gif][]

图2 应用程序名

其中应用程序名要填写带包名的完整名称，比如这里为om.ichliebephone.c2dm. AndroidC2DMDemo。

![0_1310033540ZjRg.gif][]

图3 C2DM用户账户注册

这里的contact邮箱使用一个你能接收到邮件的邮箱即可，下面的Role（sender）account邮箱最好单独注册一个Gmail邮箱来使用C2DM服务。[我们这里使用的是专门注册的android.c2dm.deno@gmail.com][android.c2dm.deno_gmail.com]邮箱。

提交后，过一段时间就会收到Google发送过来的确认邮件，然后你就可以使用C2DM的Push服务了。

介绍了这么多，我们先来快速完成一个实例，只完成Android设备端的注册部分，不包含向服务器发送registration\_id和服务器向C2DM服务器发送数据的具体代码，这部分只是用Ubuntu下的curl命令来模拟，主要是快速亲自体验一下Push的结果。

创建一个Android工程AndroidC2DMDemo，并且包含进Google的开源例子[Chrome To Phone][]中的c2dm包com.google.android.c2dm，包中包含三个Java类，分别为：

第一个类为C2DMBaseReceiver：

**\[java\]** [ view plain][view plain] [copy][view plain] [print][view plain] [?][view plain]

1.  /\*
2.   \* Copyright 2010 Google Inc.
3.   \*
4.   \* Licensed under the Apache License, Version 2.0 (the "License");
5.   \* you may not use this file except in compliance with the License.
6.   \* You may obtain a copy of the License at
7.   \*
8.   \* http://www.apache.org/licenses/LICENSE-2.0
9.   \*
10.  \* Unless required by applicable law or agreed to in writing, software
11.  \* distributed under the License is distributed on an "AS IS" BASIS,
12.  \* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13.  \* See the License for the specific language governing permissions and
14.  \* limitations under the License.
15.  \*/
16. 
17. package com.google.android.c2dm;
18. 
19. import java.io.IOException;
20. 
21. import android.app.AlarmManager;
22. import android.app.IntentService;
23. import android.app.PendingIntent;
24. import android.content.Context;
25. import android.content.Intent;
26. import android.os.PowerManager;
27. import android.util.Log;
28. 
29. /\*\*
30.  \* Base class for C2D message receiver. Includes constants for the
31.  \* strings used in the protocol.
32.  \*/
33. /\*\*
34.  \* 接收和处理C2DM消息的基类
35.  \* \*/
36. public abstract class C2DMBaseReceiver extends IntentService \{
37. //和C2DM Push的Intent内容相关 
38. //重新向C2DM服务器注册 
39. private static final String C2DM\_RETRY = "com.google.android.c2dm.intent.RETRY";
40. //向C2DM服务器注册后的回调处理 
41. public static final String REGISTRATION\_CALLBACK\_INTENT = "com.google.android.c2dm.intent.REGISTRATION";
42. //接收到C2DM服务器的推送消息 
43. private static final String C2DM\_INTENT = "com.google.android.c2dm.intent.RECEIVE";
44. 
45. // Logging tag 
46. private static final String TAG = "C2DM";
47. 
48. // Extras in the registration callback intents. 
49. //向C2DM注册返回的intent中包含的key 
50. public static final String EXTRA\_UNREGISTERED = "unregistered";
51. public static final String EXTRA\_ERROR = "error";
52. public static final String EXTRA\_REGISTRATION\_ID = "registration\_id";
53. //向C2DM注册出错的原因 
54. public static final String ERR\_SERVICE\_NOT\_AVAILABLE = "SERVICE\_NOT\_AVAILABLE";
55. public static final String ERR\_ACCOUNT\_MISSING = "ACCOUNT\_MISSING";
56. public static final String ERR\_AUTHENTICATION\_FAILED = "AUTHENTICATION\_FAILED";
57. public static final String ERR\_TOO\_MANY\_REGISTRATIONS = "TOO\_MANY\_REGISTRATIONS";
58. public static final String ERR\_INVALID\_PARAMETERS = "INVALID\_PARAMETERS";
59. public static final String ERR\_INVALID\_SENDER = "INVALID\_SENDER";
60. public static final String ERR\_PHONE\_REGISTRATION\_ERROR = "PHONE\_REGISTRATION\_ERROR";
61. 
62. // wakelock 
63. private static final String WAKELOCK\_KEY = "C2DM\_LIB";
64. 
65. private static PowerManager.WakeLock mWakeLock;
66. private final String senderId;
67. 
68. /\*\*
69.  \* The C2DMReceiver class must create a no-arg constructor and pass the 
70.  \* sender id to be used for registration.
71.  \*/
72. public C2DMBaseReceiver(String senderId) \{
73. // senderId is used as base name for threads, etc. 
74. super(senderId);
75. this.senderId = senderId;
76. \}
77. //下面几个是接收到C2DM Push过来的信息后的回调函数，都可以在继承的子类中处理 
78. /\*\*
79.  \* Called when a cloud message has been received.
80.  \*/
81. /\*\*
82.  \* 接收到C2DM服务器Push的消息后的回调函数，需要在继承的子类中处理
83.  \* \*/
84. protected abstract void onMessage(Context context, Intent intent);
85. 
86. /\*\*
87.  \* Called on registration error. Override to provide better
88.  \* error messages.
89.  \* 
90.  \* This is called in the context of a Service - no dialog or UI.
91.  \*/
92. /\*\*
93.  \* 出错的回调函数
94.  \* \*/
95. public abstract void onError(Context context, String errorId);
96. 
97. /\*\*
98.  \* Called when a registration token has been received.
99.  \*/
100. /\*\*
101.  \* 注册后的回调函数
102.  \* \*/
103. public void onRegistered(Context context, String registrationId) throws IOException \{
104. // registrationId will also be saved 
105. \}
106. 
107. /\*\*
108.  \* Called when the device has been unregistered.
109.  \*/
110. /\*\*
111.  \* 取消注册的回调函数
112.  \* \*/
113. public void onUnregistered(Context context) \{
114. \}
115. 
116. //IntentService的方法 
117. @Override
118. public final void onHandleIntent(Intent intent) \{
119. try \{
120. Context context = getApplicationContext();
121. if (intent.getAction().equals(REGISTRATION\_CALLBACK\_INTENT)) \{
122. handleRegistration(context, intent);//处理注册后的回调 
123. \} else if (intent.getAction().equals(C2DM\_INTENT)) \{
124. onMessage(context, intent);//处理C2DM Push消息的回调 
125. \} else if (intent.getAction().equals(C2DM\_RETRY)) \{
126. C2DMessaging.register(context, senderId); //重新注册 
127. \}
128. \} finally \{
129. // Release the power lock, so phone can get back to sleep. 
130. // The lock is reference counted by default, so multiple 
131. // messages are ok. 
132. 
133. // If the onMessage() needs to spawn a thread or do something else, 
134. // it should use it's own lock. 
135. mWakeLock.release();
136. \}
137. \}
138. 
139. 
140. /\*\*
141.  \* Called from the broadcast receiver. 
142.  \* Will process the received intent, call handleMessage(), registered(), etc.
143.  \* in background threads, with a wake lock, while keeping the service 
144.  \* alive. 
145.  \*/
146. static void runIntentInService(Context context, Intent intent) \{
147. if (mWakeLock == null) \{
148. // This is called from BroadcastReceiver, there is no init. 
149. PowerManager pm =
150. (PowerManager) context.getSystemService(Context.POWER\_SERVICE);
151. mWakeLock = pm.newWakeLock(PowerManager.PARTIAL\_WAKE\_LOCK,
152. WAKELOCK\_KEY);
153. \}
154. mWakeLock.acquire();
155. 
156. // Use a naming convention, similar with how permissions and intents are 
157. // used. Alternatives are introspection or an ugly use of statics. 
158. String receiver = context.getPackageName() + ".C2DMReceiver";
159. intent.setClassName(context, receiver);
160. 
161. context.startService(intent);
162. 
163. \}
164. 
165. //处理注册后的回调 
166. private void handleRegistration(final Context context, Intent intent) \{
167. final String registrationId = intent.getStringExtra(EXTRA\_REGISTRATION\_ID);
168. String error = intent.getStringExtra(EXTRA\_ERROR);
169. String removed = intent.getStringExtra(EXTRA\_UNREGISTERED);
170. Log.v(TAG, "handleRegistration");
171. //打印出接收到的registraton\_id 
172. Log.v(TAG, "dmControl: registrationId = " \+ registrationId +
173. ", error = " \+ error + ", removed = " \+ removed);
174. if (Log.isLoggable(TAG, Log.DEBUG)) \{
175. Log.d(TAG, "dmControl: registrationId = " \+ registrationId +
176. ", error = " \+ error + ", removed = " \+ removed);
177. \}
178. if (removed != null) \{
179. // Remember we are unregistered 
180. C2DMessaging.clearRegistrationId(context);
181. onUnregistered(context);
182. return;
183. \} else if (error != null) \{
184. // we are not registered, can try again 
185. C2DMessaging.clearRegistrationId(context);
186. // Registration failed 
187. Log.e(TAG, "Registration error " \+ error);
188. onError(context, error);
189. if ("SERVICE\_NOT\_AVAILABLE".equals(error)) \{
190. long backoffTimeMs = C2DMessaging.getBackoff(context);
191. 
192. Log.d(TAG, "Scheduling registration retry, backoff = " \+ backoffTimeMs);
193. Intent retryIntent = new Intent(C2DM\_RETRY);
194. PendingIntent retryPIntent = PendingIntent.getBroadcast(context,
195. 0 /\*requestCode\*/, retryIntent, 0 /\*flags\*/);
196. 
197. AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM\_SERVICE);
198. am.set(AlarmManager.ELAPSED\_REALTIME,
199. backoffTimeMs, retryPIntent);
200. 
201. // Next retry should wait longer. 
202. backoffTimeMs \*= 2;
203. C2DMessaging.setBackoff(context, backoffTimeMs);
204. \}
205. \} else \{
206. try \{
207. onRegistered(context, registrationId);
208. C2DMessaging.setRegistrationId(context, registrationId);
209. \} catch (IOException ex) \{
210. Log.e(TAG, "Registration error " \+ ex.getMessage());
211. \}
212. \}
213. \}
214. \}

/*
     * Copyright 2010 Google Inc.
     *
     * Licensed under the Apache License, Version 2.0 (the "License");
     * you may not use this file except in compliance with the License.
     * You may obtain a copy of the License at
     *
     *   http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     */
    
    package com.google.android.c2dm;
    
    import java.io.IOException;
    
    import android.app.AlarmManager;
    import android.app.IntentService;
    import android.app.PendingIntent;
    import android.content.Context;
    import android.content.Intent;
    import android.os.PowerManager;
    import android.util.Log;
    
    /**
     * Base class for C2D message receiver. Includes constants for the
     * strings used in the protocol.
     */
    /**
     * 接收和处理C2DM消息的基类
     * */
    public abstract class C2DMBaseReceiver extends IntentService {
    	//和C2DM Push的Intent内容相关
    	//重新向C2DM服务器注册
        private static final String C2DM_RETRY = "com.google.android.c2dm.intent.RETRY";   
        //向C2DM服务器注册后的回调处理
        public static final String REGISTRATION_CALLBACK_INTENT = "com.google.android.c2dm.intent.REGISTRATION";  
        //接收到C2DM服务器的推送消息
        private static final String C2DM_INTENT = "com.google.android.c2dm.intent.RECEIVE";
    
        // Logging tag
        private static final String TAG = "C2DM";
    
        // Extras in the registration callback intents.
        //向C2DM注册返回的intent中包含的key
        public static final String EXTRA_UNREGISTERED = "unregistered";
        public static final String EXTRA_ERROR = "error";
        public static final String EXTRA_REGISTRATION_ID = "registration_id";
        //向C2DM注册出错的原因
        public static final String ERR_SERVICE_NOT_AVAILABLE = "SERVICE_NOT_AVAILABLE";
        public static final String ERR_ACCOUNT_MISSING = "ACCOUNT_MISSING";
        public static final String ERR_AUTHENTICATION_FAILED = "AUTHENTICATION_FAILED";
        public static final String ERR_TOO_MANY_REGISTRATIONS = "TOO_MANY_REGISTRATIONS";
        public static final String ERR_INVALID_PARAMETERS = "INVALID_PARAMETERS";
        public static final String ERR_INVALID_SENDER = "INVALID_SENDER";
        public static final String ERR_PHONE_REGISTRATION_ERROR = "PHONE_REGISTRATION_ERROR";
        
        // wakelock
        private static final String WAKELOCK_KEY = "C2DM_LIB";
    
        private static PowerManager.WakeLock mWakeLock;
        private final String senderId;
    
        /**
         * The C2DMReceiver class must create a no-arg constructor and pass the 
         * sender id to be used for registration.
         */
        public C2DMBaseReceiver(String senderId) {
            // senderId is used as base name for threads, etc.
            super(senderId);
            this.senderId = senderId;
        }
        //下面几个是接收到C2DM Push过来的信息后的回调函数，都可以在继承的子类中处理
        /**
         * Called when a cloud message has been received.
         */
        /**
         * 接收到C2DM服务器Push的消息后的回调函数，需要在继承的子类中处理
         * */
        protected abstract void onMessage(Context context, Intent intent);
    
        /**
         * Called on registration error. Override to provide better
         * error messages.
         *  
         * This is called in the context of a Service - no dialog or UI.
         */
        /**
         * 出错的回调函数
         * */
        public abstract void onError(Context context, String errorId);
    
        /**
         * Called when a registration token has been received.
         */
        /**
         * 注册后的回调函数
         * */
        public void onRegistered(Context context, String registrationId) throws IOException {
            // registrationId will also be saved
        }
    
        /**
         * Called when the device has been unregistered.
         */
        /**
         * 取消注册的回调函数
         * */
        public void onUnregistered(Context context) {
        }
    
        //IntentService的方法
        @Override
        public final void onHandleIntent(Intent intent) {
            try {
                Context context = getApplicationContext();
                if (intent.getAction().equals(REGISTRATION_CALLBACK_INTENT)) {
                    handleRegistration(context, intent);//处理注册后的回调
                } else if (intent.getAction().equals(C2DM_INTENT)) {
                    onMessage(context, intent);//处理C2DM Push消息的回调
                } else if (intent.getAction().equals(C2DM_RETRY)) {
                    C2DMessaging.register(context, senderId); //重新注册
                }
            } finally {
                //  Release the power lock, so phone can get back to sleep.
                // The lock is reference counted by default, so multiple 
                // messages are ok.
                
                // If the onMessage() needs to spawn a thread or do something else,
                // it should use it's own lock.
                mWakeLock.release();
            }
        }
    
        
        /**
         * Called from the broadcast receiver. 
         * Will process the received intent, call handleMessage(), registered(), etc.
         * in background threads, with a wake lock, while keeping the service 
         * alive. 
         */
        static void runIntentInService(Context context, Intent intent) {
            if (mWakeLock == null) {
                // This is called from BroadcastReceiver, there is no init.
                PowerManager pm = 
                    (PowerManager) context.getSystemService(Context.POWER_SERVICE);
                mWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, 
                        WAKELOCK_KEY);
            }
            mWakeLock.acquire();
           
            // Use a naming convention, similar with how permissions and intents are 
            // used. Alternatives are introspection or an ugly use of statics. 
            String receiver = context.getPackageName() + ".C2DMReceiver";
            intent.setClassName(context, receiver);
            
            context.startService(intent);
    
        }
        
        //处理注册后的回调
        private void handleRegistration(final Context context, Intent intent) {
            final String registrationId = intent.getStringExtra(EXTRA_REGISTRATION_ID);
            String error = intent.getStringExtra(EXTRA_ERROR);
            String removed = intent.getStringExtra(EXTRA_UNREGISTERED);
            Log.v(TAG, "handleRegistration");
            //打印出接收到的registraton_id
            Log.v(TAG, "dmControl: registrationId = " + registrationId +
                    ", error = " + error + ", removed = " + removed);
            if (Log.isLoggable(TAG, Log.DEBUG)) {
                Log.d(TAG, "dmControl: registrationId = " + registrationId +
                    ", error = " + error + ", removed = " + removed);
            }
            if (removed != null) {
                // Remember we are unregistered
                C2DMessaging.clearRegistrationId(context);
                onUnregistered(context);
                return;
            } else if (error != null) {
                // we are not registered, can try again
                C2DMessaging.clearRegistrationId(context);
                // Registration failed
                Log.e(TAG, "Registration error " + error);
                onError(context, error);
                if ("SERVICE_NOT_AVAILABLE".equals(error)) {
                    long backoffTimeMs = C2DMessaging.getBackoff(context);
                    
                    Log.d(TAG, "Scheduling registration retry, backoff = " + backoffTimeMs);
                    Intent retryIntent = new Intent(C2DM_RETRY);
                    PendingIntent retryPIntent = PendingIntent.getBroadcast(context, 
                            0 /*requestCode*/, retryIntent, 0 /*flags*/);
                    
                    AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
                    am.set(AlarmManager.ELAPSED_REALTIME,
                            backoffTimeMs, retryPIntent);
    
                    // Next retry should wait longer.
                    backoffTimeMs *= 2;
                    C2DMessaging.setBackoff(context, backoffTimeMs);
                } 
            } else {
                try {
                    onRegistered(context, registrationId);
                    C2DMessaging.setRegistrationId(context, registrationId);
                } catch (IOException ex) {
                    Log.e(TAG, "Registration error " + ex.getMessage());
                }
            }
        }
    }

第二个类为C2DMBroadcastReceiver：

**\[java\]** [ view plain][view plain] [copy][view plain] [print][view plain] [?][view plain]

1.  /\*
2.   \*/
3.  package com.google.android.c2dm;
4.  
5.  import android.app.Activity;
6.  import android.content.BroadcastReceiver;
7.  import android.content.Context;
8.  import android.content.Intent;
9.  
10. /\*\*
11.  \* Helper class to handle BroadcastReciver behavior.
12.  \* - can only run for a limited amount of time - it must start a real service 
13.  \* for longer activity
14.  \* - must get the power lock, must make sure it's released when all done.
15.  \* 
16.  \*/
17. /\*\*
18.  \* 帮助类，帮忙处理BroadcastReciver过程
19.  \* \*/
20. public class C2DMBroadcastReceiver extends BroadcastReceiver \{
21. 
22. @Override
23. public final void onReceive(Context context, Intent intent) \{
24. // To keep things in one place. 
25. C2DMBaseReceiver.runIntentInService(context, intent);
26. setResult(Activity.RESULT\_OK, null /\* data \*/, null /\* extra \*/);
27. \}
28. \}

/*
     */
    package com.google.android.c2dm;
    
    import android.app.Activity;
    import android.content.BroadcastReceiver;
    import android.content.Context;
    import android.content.Intent;
    
    /**
     * Helper class to handle BroadcastReciver behavior.
     * - can only run for a limited amount of time - it must start a real service 
     * for longer activity
     * - must get the power lock, must make sure it's released when all done.
     * 
     */
    /**
     * 帮助类，帮忙处理BroadcastReciver过程
     * */
    public class C2DMBroadcastReceiver extends BroadcastReceiver {
        
        @Override
        public final void onReceive(Context context, Intent intent) {
            // To keep things in one place.
            C2DMBaseReceiver.runIntentInService(context, intent);
            setResult(Activity.RESULT_OK, null /* data */, null /* extra */);        
        }
    }

第三个类为C2DMessaging：

**\[java\]** [ view plain][view plain] [copy][view plain] [print][view plain] [?][view plain]

代码中已添加了部分中文注释，可以先大概了解下，等整个工程建立完了在一起解释。

然后创建我们自己的包com.ichliebephone.c2dm，包含两个类，一个是工程的入口AndroidC2DMDemo：

**\[java\]** [ view plain][view plain] [copy][view plain] [print][view plain] [?][view plain]

1.  package com.ichliebephone.c2dm;
2.  
3.  import com.google.android.c2dm.C2DMessaging;
4.  
5.  import android.app.Activity;
6.  import android.os.Bundle;
7.  import android.util.Log;
8.  
9.  public class AndroidC2DMDemo extends Activity \{
10. /\*\* Called when the activity is first created. \*/
11. private static final String TAG = "AndroidC2DMDemo";
12. public static final String SENDER\_ID = "android.c2dm.demo@gmail.com"; //使用C2DM服务的用户账户 
13. public static final String MESSAGE\_KEY\_ONE = "msg"; //和服务器商量好的接收消息的键值key 
14. 
15. @Override
16. public void onCreate(Bundle savedInstanceState) \{
17. super.onCreate(savedInstanceState);
18. setContentView(R.layout.main);
19. 
20. Log.v(TAG, "Start");
21. //向C2DM服务器注册 
22. C2DMessaging.register(this, SENDER\_ID);
23. \}
24. 
25. 
26. \}

package com.ichliebephone.c2dm;
    
    import com.google.android.c2dm.C2DMessaging;
    
    import android.app.Activity;
    import android.os.Bundle;
    import android.util.Log;
    
    public class AndroidC2DMDemo extends Activity {
        /** Called when the activity is first created. */
    	private static final String TAG = "AndroidC2DMDemo";
    	public static final String SENDER_ID = "android.c2dm.demo@gmail.com"; //使用C2DM服务的用户账户
    	public static final String MESSAGE_KEY_ONE = "msg";   //和服务器商量好的接收消息的键值key
    	
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
            
            Log.v(TAG, "Start");
            //向C2DM服务器注册
            C2DMessaging.register(this, SENDER_ID);
        }
        
        
    }

很简单，就是开始向C2DM服务器进行注册。

另一个类为C2DMBaseReceiver的子类C2DMReceiver：

**\[java\]** [ view plain][view plain] [copy][view plain] [print][view plain] [?][view plain]

1.  package com.ichliebephone.c2dm;
2.  
3.  import java.io.IOException;
4.  
5.  import android.app.Notification;
6.  import android.app.NotificationManager;
7.  import android.app.PendingIntent;
8.  import android.content.Context;
9.  import android.content.Intent;
10. import android.os.Bundle;
11. import android.util.Log;
12. 
13. import com.google.android.c2dm.C2DMBaseReceiver;
14. //接收C2DM服务器Push的消息，包括注册返回的registration\_id消息，推送的数据消息等 
15. public class C2DMReceiver extends C2DMBaseReceiver\{
16. 
17. private static final String TAG="C2DMReceiver";
18. // 
19. public C2DMReceiver()
20. \{
21. super(AndroidC2DMDemo.SENDER\_ID);
22. \}
23. public C2DMReceiver(String senderId) \{
24. super(senderId);
25. // TODO Auto-generated constructor stub 
26. \}
27. //接收到Push消息的回调函数 
28. @Override
29. protected void onMessage(Context context, Intent intent) \{
30. // TODO Auto-generated method stub 
31. Log.v(TAG, "C2DMReceiver message");
32. Bundle extras = intent.getExtras();
33. if(extras!=null)\{
34. String msg = (String)extras.get(AndroidC2DMDemo.MESSAGE\_KEY\_ONE);
35. Log.v(TAG, "The received msg = "\+msg);
36. //在标题栏上显示通知 
37. NotificationManager notificationManager = (NotificationManager)getSystemService(NOTIFICATION\_SERVICE);
38. Notification notification = new Notification(R.drawable.icon, msg, System.currentTimeMillis());
39. PendingIntent contentIntent = PendingIntent.getActivity(this, 0, new Intent(this, AndroidC2DMDemo.class), 0);
40. notification.setLatestEventInfo(this, getString(R.string.app\_name), msg, contentIntent);
41. notificationManager.notify(0, notification);
42. 
43. \}
44. \}
45. 
46. @Override
47. public void onError(Context context, String errorId) \{
48. // TODO Auto-generated method stub 
49. Log.v(TAG, "C2DMReceiver error");
50. \}
51. 
52. @Override
53. public void onRegistered(Context context, String registrationId)
54. throws IOException \{
55. // TODO Auto-generated method stub 
56. super.onRegistered(context, registrationId);
57. Log.v(TAG, "C2DMReceiver Register");
58. \}
59. @Override
60. public void onUnregistered(Context context) \{
61. // TODO Auto-generated method stub 
62. super.onUnregistered(context);
63. Log.v(TAG, "C2DMReceiver UnRegister");
64. \}
65. \}

package com.ichliebephone.c2dm;
    
    import java.io.IOException;
    
    import android.app.Notification;
    import android.app.NotificationManager;
    import android.app.PendingIntent;
    import android.content.Context;
    import android.content.Intent;
    import android.os.Bundle;
    import android.util.Log;
    
    import com.google.android.c2dm.C2DMBaseReceiver;
    //接收C2DM服务器Push的消息，包括注册返回的registration_id消息，推送的数据消息等
    public class C2DMReceiver extends C2DMBaseReceiver{
    	
    	private static final String TAG="C2DMReceiver";
    	//
    	public C2DMReceiver()
    	{
    		super(AndroidC2DMDemo.SENDER_ID);
    	}
    	public C2DMReceiver(String senderId) {
    		super(senderId);
    		// TODO Auto-generated constructor stub
    	}
    	//接收到Push消息的回调函数
    	@Override
    	protected void onMessage(Context context, Intent intent) {
    		// TODO Auto-generated method stub
    		Log.v(TAG, "C2DMReceiver message");
    		Bundle extras = intent.getExtras();
    		if(extras!=null){
    			String msg = (String)extras.get(AndroidC2DMDemo.MESSAGE_KEY_ONE);
    			Log.v(TAG, "The received msg = "+msg);
    			//在标题栏上显示通知
    			NotificationManager notificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
    			Notification notification = new Notification(R.drawable.icon, msg, System.currentTimeMillis());
    			PendingIntent contentIntent = PendingIntent.getActivity(this, 0, new Intent(this, AndroidC2DMDemo.class), 0);
    			notification.setLatestEventInfo(this, getString(R.string.app_name), msg, contentIntent);
    			notificationManager.notify(0, notification);
    			
    		}
    	}
    
    	@Override
    	public void onError(Context context, String errorId) {
    		// TODO Auto-generated method stub
    		Log.v(TAG, "C2DMReceiver error");
    	}
    	
    	@Override
    	public void onRegistered(Context context, String registrationId)
    			throws IOException {
    		// TODO Auto-generated method stub
    		super.onRegistered(context, registrationId);
    		Log.v(TAG, "C2DMReceiver Register");
    	}
    	@Override
    	public void onUnregistered(Context context) {
    		// TODO Auto-generated method stub
    		super.onUnregistered(context);
    		Log.v(TAG, "C2DMReceiver UnRegister");
    	}	
    }

在这个类中我们主要在接收到Push的回调函数onMessage中对消息进行了接收，并且使用Notification的方式显示在状态栏上。

我们完整的工程目录是这样的：

![0_13100338384DtV.gif][]

图4 工程目录

最后我们还要在AndroidManifest.xml中增加对应的权限等内容:

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1.  <?xml version="1.0" encoding="utf-8"?>
2.  <manifest xmlns:android="http://schemas.android.com/apk/res/android"
3.  package="com.ichliebephone.c2dm"
4.  android:versionCode="1"
5.  android:versionName="1.0">
6.  <uses-sdk android:minSdkVersion="8" />
7.  
8.  
9.  
10. <permission android:name="com.ichliebephone.c2dm.permission.C2D\_MESSAGE"
11. android:protectionLevel="signature"></permission>
12. <uses-permission android:name="com.ichliebephone.c2dm.permission.C2D\_MESSAGE"/>
13. 
14. 
15. <uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
16. 
17. 
18. <uses-permission android:name="android.permission.INTERNET" />
19. 
20. 
21. <uses-permission android:name="android.permission.WAKE\_LOCK" />
22. <uses-permission android:name="android.permission.GET\_ACCOUNTS" />
23. <uses-permission android:name="android.permission.USE\_CREDENTIALS" />
24. 
25. <application android:icon="@drawable/icon" android:label="@string/app\_name">
26. <activity android:name=".AndroidC2DMDemo"
27. android:label="@string/app\_name">
28. <intent-filter>
29. <action android:name="android.intent.action.MAIN" />
30. <category android:name="android.intent.category.LAUNCHER" />
31. </intent-filter>
32. </activity>
33. 
34. 
38. 
41. <service android:name=".C2DMReceiver" />
42. 
43. 
45. 
46. <receiver android:name="com.google.android.c2dm.C2DMBroadcastReceiver"
47. android:permission="com.google.android.c2dm.permission.SEND">
48. 
49. 
50. <intent-filter>
51. <action android:name="com.google.android.c2dm.intent.RECEIVE" />
52. <category android:name="com.ichliebephone.c2dm" />
53. </intent-filter>
54. 
55. 
56. <intent-filter>
57. <action android:name="com.google.android.c2dm.intent.REGISTRATION" />
58. <category android:name="com.ichliebephone.c2dm" />
59. </intent-filter>
60. </receiver>
61. </application>
62. </manifest>

<?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.ichliebephone.c2dm"
          android:versionCode="1"
          android:versionName="1.0">
        <uses-sdk android:minSdkVersion="8" />
    
    	
    	
    	<permission android:name="com.ichliebephone.c2dm.permission.C2D_MESSAGE"
    		android:protectionLevel="signature"></permission>
    	<uses-permission android:name="com.ichliebephone.c2dm.permission.C2D_MESSAGE"/>
    	
    	
    	<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
    	
    	
    	<uses-permission android:name="android.permission.INTERNET" />
    	
    	
        <uses-permission android:name="android.permission.WAKE_LOCK" />
        <uses-permission android:name="android.permission.GET_ACCOUNTS" />
        <uses-permission android:name="android.permission.USE_CREDENTIALS" />
        
        <application android:icon="@drawable/icon" android:label="@string/app_name">
            <activity android:name=".AndroidC2DMDemo"
                      android:label="@string/app_name">
                <intent-filter>
                    <action android:name="android.intent.action.MAIN" />
                    <category android:name="android.intent.category.LAUNCHER" />
                </intent-filter>
            </activity>
    		
    		
                 
            <service android:name=".C2DMReceiver" />
                    
             
            
            <receiver android:name="com.google.android.c2dm.C2DMBroadcastReceiver"
                      android:permission="com.google.android.c2dm.permission.SEND">
                
                
                <intent-filter>
                    <action android:name="com.google.android.c2dm.intent.RECEIVE" />
                    <category android:name="com.ichliebephone.c2dm" />
                </intent-filter>
                
                
                <intent-filter>
                    <action android:name="com.google.android.c2dm.intent.REGISTRATION" />
                    <category android:name="com.ichliebephone.c2dm" />
                </intent-filter>
            </receiver>
        </application>
    </manifest>

因为C2DM功能只有2.2及以上的Android系统才支持，因此创建一个2.2及以上的AVD，然后在”设置->账户与同步”里还要设置好Google Account，如下图所示：

![0_13100339312b59.gif][]

图5 设置Android设备中的Google账户

然后就可以运行程序了，我们会在DDMS输出中看到获得的registration\_id：

![0_1310033964pTr3.gif][]

图6 获得的registration\_id

如果第一次运行没有出现，试着再运行一次。

有了registration\_id，我们的服务器端就可以向C2DM端发送需要Push的数据了，这里进行简单化处理下，在Ubuntu下直接使用curl命令来模拟服务器功能向C2DM发送数据。

我们先来获取C2DM的ClientLogin权限Auth，在Ubuntu终端下输入：

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1.  lingaohe@lingaohe-laptop:~$ curl -d "accountType=HOSTED\_OR\_GOOGLE&Email=android.c2dm.demo@gmail.com&Passwd=androidc2dmdemo&service=ac2dm&source=bupt-c2dmdemo-1.0" https://www.google.com/accounts/ClientLogin

lingaohe@lingaohe-laptop:~$ curl -d "accountType=HOSTED_OR_GOOGLE&Email=android.c2dm.demo@gmail.com&Passwd=androidc2dmdemo&service=ac2dm&source=bupt-c2dmdemo-1.0" https://www.google.com/accounts/ClientLogin

这个表示以POST的方式向[https://www.google.com/accounts/ClientLogin][https_www.google.com_accounts_ClientLogin]发送数据，其中把Email和Passwd换成你自己在C2DM网页上注册的邮箱号和密码。

如果你的邮箱已在C2DM网页上注册，并且密码没有错误的话就会返回需要的Auth内容：

**\[plain\]** [ view plain][view plain] [copy][view plain] [print][view plain] [?][view plain]

1.  SID=DQAAAKYAAADcTtHbBBNcZJEOfkfVRycD\_ZOIidwsQ3UwIY7cSrYWaY6uhlfo0l9gRPB-mQxP4K2T5tWiG--vWVmSTeq5p8SPwgnsYvfzj7bkNiPPIy4xRimVVfBmAHnZgLohw7gHMKi5DS6kK-Ut5tNzdTkI0I2tUDF0ryQ7MnPpI6Sj-gUCyBXmvKatHHDnNTTV78XdGIx7FYej1DyqGsPsYo3bCstHgltjv3cd2Hs7D4yrpUWHZw
2.  LSID=DQAAAKgAAABCpaoUE4XvxM24Cofntw1IUGx5fKxX-m7aqTL0zhunP0OjzJ2sn9ywmPa1BMZ2cF2IchuxHFLVzaSQfydAmiHZJGXLgaUorpIN6yz1e0VFWKmS6j4wGjZOos3QoJ9rkha0jKbOiHfBesADjxk-qjJ24TJ0RL-xkZHQyzS69YlA1KyzqIKjAMCzgqaDfCwhqxylJzizJksO2h8xpAFXZ38d\_grm8XYZtzejiCiAMAR65A
3.  Auth=DQAAAKoAAACRF4pgYULnXULoWgbwfdqmMiRhfZYa1l-LW\_rwGD7cofov4L4c2bVrtCOXbEbkju\_hhqdAonpMkrb5icptt28fU8c-s-u1y2MXNYDxPIdQzfA2t6oI3NTmyj35MpsR1NKL4TN7ZVEn6z9NueuiKAqLHukZYh1YMGkGC8M6rVvA7AWPW36064XCQED7KLVNp\_pGT00lrni7UdZKZWEy0FT-EVR-OxDyHWw6C-5Kmfkisw

SID=DQAAAKYAAADcTtHbBBNcZJEOfkfVRycD_ZOIidwsQ3UwIY7cSrYWaY6uhlfo0l9gRPB-mQxP4K2T5tWiG--vWVmSTeq5p8SPwgnsYvfzj7bkNiPPIy4xRimVVfBmAHnZgLohw7gHMKi5DS6kK-Ut5tNzdTkI0I2tUDF0ryQ7MnPpI6Sj-gUCyBXmvKatHHDnNTTV78XdGIx7FYej1DyqGsPsYo3bCstHgltjv3cd2Hs7D4yrpUWHZw
    LSID=DQAAAKgAAABCpaoUE4XvxM24Cofntw1IUGx5fKxX-m7aqTL0zhunP0OjzJ2sn9ywmPa1BMZ2cF2IchuxHFLVzaSQfydAmiHZJGXLgaUorpIN6yz1e0VFWKmS6j4wGjZOos3QoJ9rkha0jKbOiHfBesADjxk-qjJ24TJ0RL-xkZHQyzS69YlA1KyzqIKjAMCzgqaDfCwhqxylJzizJksO2h8xpAFXZ38d_grm8XYZtzejiCiAMAR65A
    Auth=DQAAAKoAAACRF4pgYULnXULoWgbwfdqmMiRhfZYa1l-LW_rwGD7cofov4L4c2bVrtCOXbEbkju_hhqdAonpMkrb5icptt28fU8c-s-u1y2MXNYDxPIdQzfA2t6oI3NTmyj35MpsR1NKL4TN7ZVEn6z9NueuiKAqLHukZYh1YMGkGC8M6rVvA7AWPW36064XCQED7KLVNp_pGT00lrni7UdZKZWEy0FT-EVR-OxDyHWw6C-5Kmfkisw

返回的内容包括SID，LSID和Auth三个部分，其中Auth是我们需要的内容。

有了Auth和registration\_id值后，我们就可以继续用curl命令模拟我们自己服务器的功能向C2DM发送要推送的数据：

**\[plain\]** [ view plain][view plain] [copy][view plain] [print][view plain] [?][view plain]

1.  lingaohe@lingaohe-laptop:~$ curl -H "Authorization:GoogleLogin auth=DQAAAKoAAACRF4pgYULnXULoWgbwfdqmMiRhfZYa1l-LW\_rwGD7cofov4L4c2bVrtCOXbEbkju\_hhqdAonpMkrb5icptt28fU8c-s-u1y2MXNYDxPIdQzfA2t6oI3NTmyj35MpsR1NKL4TN7ZVEn6z9NueuiKAqLHukZYh1YMGkGC8M6rVvA7AWPW36064XCQED7KLVNp\_pGT00lrni7UdZKZWEy0FT-EVR-OxDyHWw6C-5Kmfkisw" -d "registration\_id=APA91bGUBoSvt3G5Ny9t0IGLmIKAKYX6G6VHwSQHh3tP2fqcaQ0N4GPdKh5B3RDUHFCFF06YwT8ifOP\_cOy5BAWyCLHL8d8NpuIW9AqXt9h2JSBVF2MitZA&collapse\_key=1&data.msg=ichliebejiajia" https://android.apis.google.com/c2dm/send

lingaohe@lingaohe-laptop:~$ curl -H "Authorization:GoogleLogin auth=DQAAAKoAAACRF4pgYULnXULoWgbwfdqmMiRhfZYa1l-LW_rwGD7cofov4L4c2bVrtCOXbEbkju_hhqdAonpMkrb5icptt28fU8c-s-u1y2MXNYDxPIdQzfA2t6oI3NTmyj35MpsR1NKL4TN7ZVEn6z9NueuiKAqLHukZYh1YMGkGC8M6rVvA7AWPW36064XCQED7KLVNp_pGT00lrni7UdZKZWEy0FT-EVR-OxDyHWw6C-5Kmfkisw" -d "registration_id=APA91bGUBoSvt3G5Ny9t0IGLmIKAKYX6G6VHwSQHh3tP2fqcaQ0N4GPdKh5B3RDUHFCFF06YwT8ifOP_cOy5BAWyCLHL8d8NpuIW9AqXt9h2JSBVF2MitZA&collapse_key=1&data.msg=ichliebejiajia" https://android.apis.google.com/c2dm/send

其中发送的数据部分为data.msg=ichliebejiajia，表示发送的数据内容为ichliebejiajia，键值为msg，键值得和Android终端上的程序统一好，以便终端上可以获取。如果发送成功，会返回一个id值，比如：

**\[plain\]** [ view plain][view plain] [copy][view plain] [print][view plain] [?][view plain]

1.  id=0:1308623423080544%6c5c15c200000031
2.  lingaohe@lingaohe-laptop:~$

id=0:1308623423080544%6c5c15c200000031
    lingaohe@lingaohe-laptop:~$

这时我们的服务器就已经把数据发送给C2DM服务器了，Android设备上一会就能接收到C2DM服务器Push的数据。

在我们的例子中我们可以看到DDMS中打印出的消息：

![0_1310034130esNp.gif][]

图7 获取到的Push数据

同时Android模拟器的状态栏上会有对应的通知显示：

![0_1310034169uvv8.gif][]

图8 Android模拟器接收到的Push数据

这样我们就快速实现了下Android的C2DM框架的Push功能。进一步的具体解释说明及服务器端的代码处理我们以后再学习。

文章对应的完整代码例子下载地址：

[http://download.csdn.net/source/3425855][http_download.csdn.net_source_3425855]

[C2DM]: http://code.google.com/android/c2dm/index.html
[Link 1]: http://code.google.com/android/c2dm/signup.html
[0_1310033311Jzf9.gif]: http://hi.csdn.net/attachment/201107/7/0_1310033311Jzf9.gif
[0_1310033516Nnpp.gif]: http://hi.csdn.net/attachment/201107/7/0_1310033516Nnpp.gif
[0_1310033540ZjRg.gif]: http://hi.csdn.net/attachment/201107/7/0_1310033540ZjRg.gif
[android.c2dm.deno_gmail.com]: mailto:我们这里使用的是专门注册的android.c2dm.deno@gmail.com
[Chrome To Phone]: http://code.google.com/p/chrometophone/
[view plain]: http://blog.csdn.net/ichliebephone/article/details/6591071#
[0_13100338384DtV.gif]: http://hi.csdn.net/attachment/201107/7/0_13100338384DtV.gif
[0_13100339312b59.gif]: http://hi.csdn.net/attachment/201107/7/0_13100339312b59.gif
[0_1310033964pTr3.gif]: http://hi.csdn.net/attachment/201107/7/0_1310033964pTr3.gif
[https_www.google.com_accounts_ClientLogin]: https://www.google.com/accounts/ClientLogin
[0_1310034130esNp.gif]: http://hi.csdn.net/attachment/201107/7/0_1310034130esNp.gif
[0_1310034169uvv8.gif]: http://hi.csdn.net/attachment/201107/7/0_1310034169uvv8.gif
[http_download.csdn.net_source_3425855]: http://download.csdn.net/source/3425855