IOS客户端的APNS服务简介与实现

APNs －－Apple Push Notification Service

APNs 苹果推送服务器
Device 安装带有推送服务程序的iPhone手机
Provider 程序服务器，把需要推送的信息发给 APNs
DeviceToken 在Device第一次连接APNs时，由APNs生成的经过加密的连接认证信息。在以后的连接中，无论时Provider到APNs还是APNs到Device 都需要 DeviceToken作为认证。
Payload 需要推送的消息的主体内容。alert－alert消息的消息体，按键标题等badge－显示在程序icon右上角的数字，sound－声音提示文件的文件名，该声音资源文件要在程序包中。

整体流程大体分为五个步骤：
1: Device －－> 连接－－> APNs 获取 DeviceToken
2: Device－－>连接－－>Provider提供DeviceToken



3: Provider侦测需要push的消息生成Notification信息



4: Provider侦把要push的消息推送到APNs
5: APNs把该消息推送到手机



介绍完APNS的概况，下面再了解一下具体的实现方法:

注：先申请APNS的证书，再进行以下操作。

1. 将app注册notification里面, 并从APNS上获取测试机的deviceToken.

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

[[UIApplication sharedApplication] registerForRemoteNotificationTypes:(UIRemoteNotificationTypeBadge | UIRemoteNotificationTypeSound)];

// other codes here.

return YES;

}

- (void)application:(UIApplication *)application didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)deviceToken {

NSLog(@"deviceToken: %@", deviceToken);

}

- (void)application:(UIApplication *)application didFailToRegisterForRemoteNotificationsWithError:(NSError *)error {

NSLog(@"Error in registration. Error: %@", error);

}

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo

{

NSLog(@" 收到推送消息 ： %@",[[userInfo objectForKey:@"aps"] objectForKey:@"alert"]);

if ([[userInfo objectForKey:@"aps"] objectForKey:@"alert"]!=NULL) {

UIAlertView* alert = [[UIAlertView alloc] initWithTitle:@"推送通知"

message:[[userInfo objectForKey:@"aps"] objectForKey:@"alert"]

delegate:self

cancelButtonTitle:@" 关闭"

otherButtonTitles:@" 更新状态",nil];

[alert show];

[alert release];

}

}

启动程序，将app注册到通知项后，在console里面找到打印的deviceToken：

deviceToken: <6974ac11 870e09fa 00e2238e 8cfafc7d 2052e342 182f5b57 fabca445 42b72e1b>

2. 生成app在服务端需要的许可证
1）进入Provisioning Portal, 下载Certificates在development下的证书。
2） 找到需要测试的app id,然后enable它在development下的Apple Push Notification service: Development Push SSL Certificate。需要输入1）中的签名证书才可以生成一个aps_developer_identity.cer.
3) 双击aps_developer_identity.cer，会打开系统的key chain. 在My certificates下找到Apple Development Push Services。需要为certificate和它之下的private key各自export出一个.p12文件。(会出现设置密码过程)
4）需要将上面的2个.p12文件转成.pem格式：

openssl pkcs12 -clcerts -nokeys -out cert.pem -in cert.p12

openssl pkcs12 -nocerts -out key.pem -in key.p12

5）如果需要对 key不进行加密：

openssl rsa -in key.pem -out key.unencrypted.pem

6）然后就可以 合并两个.pem文件, 这个ck.pem就是服务端需要的证书了。

cat cert.pem key.unencrypted.pem > ck.pem

3. 服务端push通知到ANPS. 在cocoachina找到了两种方法:
1）php驱动。需要将ck.pem和php脚本放到server 上。全部的php代码是：

<?php

$deviceToken = '6974ac11 870e09fa 00e2238e 8cfafc7d 2052e342 182f5b57 fabca445 42b72e1b';

$pass = '123456'; // Passphrase for the private key (ck.pem file)

// Get the parameters from http get or from command line

$message = $_GET['message'] or $message = $argv[1] or $message = 'A test message from worldcup';

$badge = (int)$_GET['badge'] or $badge = (int)$argv[2];

$sound = $_GET['sound'] or $sound = $argv[3];

// Construct the notification payload

$body = array();

$body['aps'] = array('alert' => $message);

if ($badge)

$body['aps']['badge'] = $badge;

if ($sound)

$body['aps']['sound'] = $sound;

/* End of Configurable Items */

$ctx = stream_context_create();

stream_context_set_option($ctx, 'ssl', 'local_cert', 'ck.pem');

// assume the private key passphase was removed.

stream_context_set_option($ctx, 'ssl', 'passphrase', $pass);

// connect to apns

$fp = stream_socket_client('ssl://gateway.sandbox.push.apple.com:2195', $err, $errstr, 60, STREAM_CLIENT_CONNECT, $ctx);

if (!$fp) {

print "Failed to connect $err $errstr\n";

return;

}

else {

print "Connection OK\n<br/>";

}

// send message

$payload = json_encode($body);

$msg = chr(0) . pack("n",32) . pack('H*', str_replace(' ', '', $deviceToken)) . pack("n",strlen($payload)) . $payload;

print "Sending message :" . $payload . "\n";

fwrite($fp, $msg);

fclose($fp);

?>

请 求一次 http://127.0.0.1/apns/apns.php?message=A%20test%20message%20from%20localhost&badge=2&sound=received5.caf就 会向APNS进行一次推送。我的请求结果如下：

Connection OK

Sending message :{"aps":{"alert":"A test message from localhost","badge":2,"sound":"received5.caf"}}

参考文章
http://blog.sina.com.cn/s/blog_46e3e7db0100roqt.html http://www.cocoachina.com/iphonedev/sdk/2010/0610/1668.html
（图片来源－－apple 开发文档）