Google Cloud Messaging (以下簡稱GCM)，廣泛運用於各種APP上
何謂GCM? 如下圖框中所示
這就是GCM的主要功用了。
廢話不多說，馬上進入主題
GCM 是由Google提供的服務之一，詳情請到 Google Cloud Messaging for Android 觀看
如何運作的呢? 大致上流程是
一、手機進入APP時向Google取得一組Registration ID (以下簡稱RegID)，再將RegID送回我們自己的Server上儲存
二、Server端廣播時，找出要廣播的RegID後，發向給Google GCM 的 Server
三、Google GCM Server幫我們向這些RegID發送訊息
實作部分
首先一定要有Google帳號～ 然後再到 Google Cloud Console
若之前無使用過Google的API 請新建一個專案(點擊 Create Project )囉～
然後會得到一組Project Number(若無找到，可以看網址上的一串數字也是專案號碼哦) 請將這組數字記下來 稍後會用到！！
之後 點選 APIs & auth 下的 APIs 找到 Google Cloud Messaging for Android 並把它改成ON的狀態
然後剛剛的APIs下有一個 Registered apps 點進去，點選上面的 REGISTER APP按鈕
輸入名稱，選擇類型 為 Android 下的 Accessing APIs via a web server
然後大力按下 Register 吧 快成功了 建立後會進入這個APP
如下圖，請把框中的API KEY記下來 等等會用到
然後開啟eclipsr吧～～～
再立馬開啟SDK Manager 安裝 Google Play Services
裝好之後建立一個Android 專案囉，至少要Android 2.3 以上
再來匯入jar檔
至SDK的安裝路徑 (..\sdk\extras\google\gcm\gcm-client\dist ) 下複製 gcm.jar
把他丟到傳案內的 libs 資料夾
再到 sdk\extras\google\google_play_services\libproject\google-play-services_lib\libs 路徑下
複製 google-play-services.jar 一樣丟到 libs
再到 \sdk\extras\google\gcm\samples\gcm-demo-client\src\com\google\android\gcm\demo\app
複製 ServerUtilities.java 、 GCMIntentService.java 、 CommonUtilities.java 到 專案下的 package
當然一開始會有錯誤
首先進入 CommonUtilities 修改使用參數
SERVER_URL -> 放置Server的IP位置
SENDER_ID -> Project Number
DISPLAY_MESSAGE_ACTION -> 填入完整的package名稱.DISPLAY_MESSAGE
package com.example.gcm_project; ... static final String SERVER_URL = "http://192.168.1.1:8080/gcm"; static final String SENDER_ID = "填入剛剛的Project Number"; static final String DISPLAY_MESSAGE_ACTION = "com.example.gcm_project.DISPLAY_MESSAGE"; ...
儲存
開啟 ServerUtilities 修改以下code
package com.example.gcm_project; import static com.example.gcm_project.CommonUtilities.SERVER_URL; import static com.example.gcm_project.CommonUtilities.TAG; import static com.example.gcm_project.CommonUtilities.displayMessage; ...
儲存後還是會有錯誤，由於使用一些gcm的string
以下code請加入string.xml 中
...
<string name="error_config">Please set the %1$s constant and recompile the app.</string>
<string name="already_registered">Device is already registered on server.</string>
<string name="gcm_registered">From GCM: device successfully registered!</string>
<string name="gcm_unregistered">From GCM: device successfully unregistered!</string>
<string name="gcm_message">From GCM: you got message!</string>
<string name="gcm_error">From GCM: error (%1$s).</string>
<string name="gcm_recoverable_error">From GCM: recoverable error (%1$s).</string>
<string name="gcm_deleted">From GCM: server deleted %1$d pending messages!</string>
<string name="server_registering">Trying (attempt %1$d/%2$d) to register device on Demo Server.</string>
<string name="server_registered">From Demo Server: successfully added device!</string>
<string name="server_unregistered">From Demo Server: successfully removed device!</string>
<string name="server_register_error">Could not register device on Demo Server after %1$d attempts.</string>
<string name="server_unregister_error">Could not unregister device on Demo Server (%1$s).</string>
<string name="options_register">Register</string>
<string name="options_unregister">Unregister</string>
<string name="options_clear">Clear</string>
<string name="options_exit">Exit</string>
...
再來開啟 GCMIntentService 修改一些code
package com.example.gcm_project; import static com.example.gcm_project.CommonUtilities.SERVER_URL; import static com.example.gcm_project.CommonUtilities.displayMessage; ...
目前這 3 個檔案算完成，開始撰寫主程式囉～
開啟 MainActivity 修改code
GoogleCloudMessaging gcm;
private Context context;
private String strRegId;
private TextView tvRegisterMsg;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tvRegisterMsg = (TextView)findViewById(R.id.action_settings);
context = getApplicationContext();
gcm = GoogleCloudMessaging.getInstance(this);
setGCM_RegID();
}
// get GCM Reg ID and Save to our server (use ServerUtilities.java)
public void setGCM_RegID() {
registerReceiver(mHandleMessageReceiver, new IntentFilter(
DISPLAY_MESSAGE_ACTION));
// register with Google.
new AsyncTask<Void, String, String>() {
@Override
protected String doInBackground(Void... params) {
String msg = "";
try {
if (gcm == null) {
gcm = GoogleCloudMessaging.getInstance(context);
}
strRegId = gcm.register(SENDER_ID);
msg = "Device registered, registration id=" + strRegId;
// send id to our server
boolean registered = ServerUtilities.register(context,
strRegId);
} catch (IOException ex) {
msg = "Error :" + ex.getMessage();
}
return msg;
}
@Override
protected void onPostExecute(String msg) {
// tvRegisterMsg.append(msg + "\n");
}
}.execute(null, null, null);
}
@Override
protected void onDestroy() {
super.onDestroy();
unregisterReceiver(mHandleMessageReceiver); // 在Activity
// 消滅時才unregister
}
// Create a broadcast receiver to get message and show on screen
private final BroadcastReceiver mHandleMessageReceiver = new BroadcastReceiver() {
private final static String MY_MESSAGE = "com.stu.phonebook.DISPLAY_MESSAGE";
@Override
public void onReceive(Context context, Intent intent) {
if (MY_MESSAGE.equals(intent.getAction())) {
final String newMessage = intent.getExtras().getString(
EXTRA_MESSAGE);
tvRegisterMsg.setText(newMessage);
}
}
};
...
修改所需要的權限～記得替換掉package的名稱哦 還有把全形" ＜ "改成半形的
開啟 AndroidManifest.xml
...
＜permission
android:name="com.example.gcm_project.permission.C2D_MESSAGE"
android:protectionLevel="signature" /＞
＜uses-permission android:name="com.example.gcm_project.permission.C2D_MESSAGE" /＞
＜uses-permission android:name="android.permission.INTERNET" /＞
＜uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" /＞
＜uses-permission android:name="android.permission.GET_ACCOUNTS" /＞
＜uses-permission android:name="android.permission.WAKE_LOCK" /＞
＜uses-permission android:name="android.permission.VIBRATE" /＞
於application中新增一個 receiver
...
＜receiver
android:name="com.google.android.gcm.GCMBroadcastReceiver"
android:permission="com.google.android.c2dm.permission.SEND" ＞
＜intent-filter＞
＜action android:name="com.google.android.c2dm.intent.RECEIVE" /＞
＜action android:name="com.google.android.c2dm.intent.REGISTRATION" /＞
＜category android:name="com.example.gcm_project" /＞
＜/intent-filter＞
＜/receiver＞
＜service android:name=".GCMIntentService" /＞
然後呢～需要建個收regId的 php 至於怎麼做...就收到存資料庫吧 很簡單
主要是要傳送GCM怎麼送呢～下面這個PHP 小範例 看一下吧
<?php
// 這支程式就是將自己模擬成 client 端,
// 發送 POST 給 Google GCM server
// function sendModifyGCM($regID){
$regID = array();
array_push($regID, $_GET["regId"]);
$apiKey = "google給你的那組key~~";
// Set POST variables
$url = 'https://android.googleapis.com/gcm/send';
$message = $_GET['message'];
$fields = array('registration_ids' => $regID,
'data' => array( 'message' => $message)
);
$headers = array('Content-Type: application/json',
'Authorization: key='.$apiKey
);
// Open connection
$ch = curl_init();
// Set the url, number of POST vars, POST data
curl_setopt( $ch, CURLOPT_URL, $url );
curl_setopt( $ch, CURLOPT_POST, true );
curl_setopt( $ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt( $ch, CURLOPT_HTTPHEADER, $headers);
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
// Disabling SSL Certificate support temporarly
// curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
// 發送的訊息內容轉成 JSON 格式
curl_setopt( $ch, CURLOPT_POSTFIELDS, json_encode( $fields ) );
// 傳送到 Google GCM server,
// 並接收回傳結果
$result = curl_exec($ch);
// Close connection
if ($result === FALSE) {
die('Curl failed: ' . curl_error($ch));
}
curl_close($ch);
echo 'result =='.$result; // 這裡只是讓您知道訊息發送結果是否成功
// }
然後就～直接去測試吧！
GET 一組regId跟 message給他吧～
正常來說～沒意外的話 就能看到手機彈出來囉 記得把app刷進手機！
Sample code
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