ios MQTT协议的实际应用

1，创建单视图项目，pod search mqtt找到一个库，然后在项目目录下pod init 出Podfile

2，pod install 安装mqtt库

3，主要代码：

#import "MQTTClient.h"
设置<MQTTSessionDelegate>

//初始化一个传输类型的实例

MQTTCFSocketTransport *transport = [[MQTTCFSocketTransport alloc] init];

transport.host = @"localhost";

transport.port = 1883;

//创建一个任务

MQTTSession *session = [[MQTTSession alloc] init];

//设置任务的传输类型

session.transport = transport;

//设置任务的代理为当前类

session.delegate = self;

//设置登录账号

session.clientId = @"lichanghong";

BOOL isSucess =   [session connectAndWaitTimeout:30];  //this is part of the synchronous API

if(isSucess){

　//以下部分是订阅一个主题

[session subscribeToTopic:@"topic" atLevel:2 subscribeHandler:^(NSError *error, NSArray<NSNumber *> *gQoss){

if (error) {

NSLog(@"Subscription failed %@", error.localizedDescription);

} else {

NSLog(@"Subscription sucessfull! Granted Qos: %@", gQoss);

}

}];

}

//发送数据  this is part of the asynchronous API

[session publishAndWaitData:[@"hello" dataUsingEncoding:NSUTF8StringEncoding]

onTopic:@"topic"

retain:NO

qos:MQTTQosLevelAtLeastOnce];

//主动和服务端断开

[session disconnect];

//取消订阅主题

[session unsubscribeTopic:@"topic" unsubscribeHandler:^(NSError *error) {

}];

- (void)newMessage:(MQTTSession *)session data:(NSData *)data onTopic:(NSString *)topic qos:(MQTTQosLevel)qos retained:(BOOL)retained mid:(unsigned int)mid

{

NSLog(@"data=%@",[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding]);

//    NSLog(@"%@",[NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil]);

}

4，服务端（php在ubuntu16.04环境下的服务器）

0)安装了composer管理php包

1）composer init创建包配置文件composer.json

发现composer太难配置，弃之。。。。

简单测试方法：

1，http://www.open-open.com/lib/view/open1384352514336.html

2，http://www.codes51.com/article/detail_2674947.html

任选其一，推荐第二个。

ubuntu安装mqtt的ppa方法：

https://launchpad.net/~mosquitto-dev/+archive/ubuntu/mosquitto-ppa

php的无法运行起来，在ubuntu16.04找不到mosquitto.so,解决方案：

 
sudo pecl install Mosquitto-alpha

and created mosquitto.ini in

/etc/php5/mods-available/mosquitto.ini

and add this code

extension=mosquitto.so