WebSocket
WebSocket 是 HTML5 一种新的协议。它实现了浏览器与服务器全双工通信，能更好的节省服务器资源和带宽并达到实时通讯，它建立在 TCP 之上，同 HTTP 一样通过 TCP 来传输数据，但是它和 HTTP 最大不同是：WebSocket 是一种双向通信协议.
由于项目需要创建一个聊天室,需要通过长链接,和后台保持通讯,进行聊天,并且实时进行热点消息的推送.
目前Facebook的SocketRocket应该是目前最好的关于SocketRocket使用的框架了.而且简单易用.
使用
一般一个项目在启动后的某个时机会启动创建一个长链接,如果需要多个就多次创建.如果只要一个就可以封装为一个单例,全局使用.
可以使用podpod管理库, 在podfile中加入
pod 'SocketRocket'
在使用命令行工具cd到当前工程 安装
pod install
导入头文件后即可使用.
为求稳定,我的做法是copy的FaceBook里SocketRocket库到项目里. --> SocketRocket地址
1.首先创建一个名为 WebSocketManager 的单例类,
+(instancetype)shared;
2.创建一个枚举,分别表示WebSocket的链接状态
typedef NS_ENUM(NSUInteger,WebSocketConnectType){ WebSocketDefault = 0, //初始状态,未连接,不需要重新连接 WebSocketConnect, //已连接 WebSocketDisconnect //连接后断开,需要重新连接};
3.创建连接
//建立长连接- (void)connectServer;
4.处理连接成功的结果;
-(void)webSocketDidOpen:(RMWebSocket *)webSocket; //连接成功回调
5.处理连接失败的结果
- (void)webSocket:(SRWebSocket *)webSocket didFailWithError:(NSError *)error;//连接失败回调
6.接收消息
///接收消息回调,需要提前和后台约定好消息格式.- (void)webSocket:(SRWebSocket *)webSocket didReceiveMessageWithString:(nonnull NSString *)string
7.关闭连接
- (void)webSocket:(SRWebSocket *)webSocket didCloseWithCode:(NSInteger)code reason:(NSString *)reason wasClean:(BOOL)wasClean;///关闭连接回调的代理
8.为保持长链接的连接状态,需要定时向后台发送消息,就是俗称的:心跳包.
需要创建一个定时器,固定时间发送消息.
9.链接断开情况处理:
首先判断是否是主动断开,如果是主动断开就不作处理.
如果不是主动断开链接,需要做重新连接的逻辑.
具体代码如下:
WebSocketManager.h 中的代码
#import<foundation foundation="" h="">#import "RMWebSocket.h"typedef NS_ENUM(NSUInteger,WebSocketConnectType){ WebSocketDefault = 0, //初始状态,未连接 WebSocketConnect, //已连接 WebSocketDisconnect //连接后断开};@class WebSocketManager;@protocol WebSocketManagerDelegate <nsobject>- (void)webSocketManagerDidReceiveMessageWithString:(NSString *)string;@endNS_ASSUME_NONNULL_BEGIN@interface WebSocketManager : NSObject@property (nonatomic, strong) RMWebSocket *webSocket;@property(nonatomic,weak) id <websocketmanagerdelegate nbsp=""> delegate;@property (nonatomic, assign) BOOL isConnect; //是否连接@property (nonatomic, assign) WebSocketConnectType connectType;+(instancetype)shared;- (void)connectServer;//建立长连接- (void)reConnectServer;//重新连接- (void)RMWebSocketClose;//关闭长连接- (void)sendDataToServer:(NSString *)data;//发送数据给服务器@endNS_ASSUME_NONNULL_END </websocketmanagerdelegate> </nsobject></foundation>
WebSocketManager.m 中的代码
#import "WebSocketManager.h"@interface WebSocketManager ()<rmwebsocketdelegate>@property (nonatomic, strong) NSTimer *heartBeatTimer; //心跳定时器@property (nonatomic, strong) NSTimer *netWorkTestingTimer; //没有网络的时候检测网络定时器@property (nonatomic, assign) NSTimeInterval reConnectTime; //重连时间@property (nonatomic, strong) NSMutableArray *sendDataArray; //存储要发送给服务端的数据@property (nonatomic, assign) BOOL isActivelyClose; //用于判断是否主动关闭长连接，如果是主动断开连接，连接失败的代理中，就不用执行 重新连接方法@end@implementation WebSocketManager+(instancetype)shared{ static WebSocketManager *_instance = nil; static dispatch_once_t onceToken; dispatch_once(&onceToken, ^{ _instance = [[self alloc]init]; }); return _instance;}- (instancetype)init{ self = [super init]; if(self){ self.reConnectTime = 0; self.isActivelyClose = NO; self.sendDataArray = [[NSMutableArray alloc] init]; } return self;}//建立长连接- (void)connectServer{ self.isActivelyClose = NO; self.webSocket.delegate = nil; [self.webSocket close]; _webSocket = nil;// self.webSocket = [[RMWebSocket alloc] initWithURL:[NSURL URLWithString:@"https://dev-im-gateway.runxsports.com/ws/token=88888888"]]; self.webSocket = [[RMWebSocket alloc] initWithURL:[NSURL URLWithString:@"ws://chat.workerman.net:7272"]]; self.webSocket.delegate = self; [self.webSocket open];}- (void)sendPing:(id)sender{ [self.webSocket sendPing:nil error:NULL];}#pragma mark --------------------------------------------------#pragma mark - socket delegate///开始连接-(void)webSocketDidOpen:(RMWebSocket *)webSocket{ NSLog(@"socket 开始连接"); self.isConnect = YES; self.connectType = WebSocketConnect; [self initHeartBeat];///开始心跳}///连接失败-(void)webSocket:(RMWebSocket *)webSocket didFailWithError:(NSError *)error{ NSLog(@"连接失败"); self.isConnect = NO; self.connectType = WebSocketDisconnect; DLog(@"连接失败，这里可以实现掉线自动重连，要注意以下几点"); DLog(@"1.判断当前网络环境，如果断网了就不要连了，等待网络到来，在发起重连"); DLog(@"3.连接次数限制，如果连接失败了，重试10次左右就可以了"); //判断网络环境 if (AFNetworkReachabilityManager.sharedManager.networkReachabilityStatus == AFNetworkReachabilityStatusNotReachable){ //没有网络 [self noNetWorkStartTestingTimer];//开启网络检测定时器 }else{ //有网络 [self reConnectServer];//连接失败就重连 }}///接收消息-(void)webSocket:(RMWebSocket *)webSocket didReceiveMessageWithString:(NSString *)string{ NSLog(@"接收消息---- %@",string); if ([self.delegate respondsToSelector:@selector(webSocketManagerDidReceiveMessageWithString:)]) { [self.delegate webSocketManagerDidReceiveMessageWithString:string]; }}///关闭连接-(void)webSocket:(RMWebSocket *)webSocket didCloseWithCode:(NSInteger)code reason:(NSString *)reason wasClean:(BOOL)wasClean{ self.isConnect = NO; if(self.isActivelyClose){ self.connectType = WebSocketDefault; return; }else{ self.connectType = WebSocketDisconnect; } DLog(@"被关闭连接，code:%ld,reason:%@,wasClean:%d",code,reason,wasClean); [self destoryHeartBeat]; //断开连接时销毁心跳 //判断网络环境 if (AFNetworkReachabilityManager.sharedManager.networkReachabilityStatus == AFNetworkReachabilityStatusNotReachable){ //没有网络 [self noNetWorkStartTestingTimer];//开启网络检测 }else{ //有网络 NSLog(@"关闭连接"); _webSocket = nil; [self reConnectServer];//连接失败就重连 }}///ping-(void)webSocket:(RMWebSocket *)webSocket didReceivePong:(NSData *)pongData{ NSLog(@"接受pong数据--> %@",pongData);}#pragma mark - NSTimer//初始化心跳- (void)initHeartBeat{ //心跳没有被关闭 if(self.heartBeatTimer) { return; } [self destoryHeartBeat]; dispatch_main_async_safe(^{ self.heartBeatTimer = [NSTimer timerWithTimeInterval:10 target:self selector:@selector(senderheartBeat) userInfo:nil repeats:true]; [[NSRunLoop currentRunLoop]addTimer:self.heartBeatTimer forMode:NSRunLoopCommonModes]; })}//重新连接- (void)reConnectServer{ if(self.webSocket.readyState == RM_OPEN){ return; } if(self.reConnectTime > 1024){ //重连10次 2^10 = 1024 self.reConnectTime = 0; return; } WS(weakSelf); dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(self.reConnectTime *NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ if(weakSelf.webSocket.readyState == RM_OPEN && weakSelf.webSocket.readyState == RM_CONNECTING) { return; } [weakSelf connectServer]; // CTHLog(@"正在重连......"); if(weakSelf.reConnectTime == 0){ //重连时间2的指数级增长 weakSelf.reConnectTime = 2; }else{ weakSelf.reConnectTime *= 2; } });}//发送心跳- (void)senderheartBeat{ //和服务端约定好发送什么作为心跳标识，尽可能的减小心跳包大小 WS(weakSelf); dispatch_main_async_safe(^{ if(weakSelf.webSocket.readyState == RM_OPEN){ [weakSelf sendPing:nil]; } });}//没有网络的时候开始定时 -- 用于网络检测- (void)noNetWorkStartTestingTimer{ WS(weakSelf); dispatch_main_async_safe(^{ weakSelf.netWorkTestingTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:weakSelf selector:@selector(noNetWorkStartTesting) userInfo:nil repeats:YES]; [[NSRunLoop currentRunLoop] addTimer:weakSelf.netWorkTestingTimer forMode:NSDefaultRunLoopMode]; });}//定时检测网络- (void)noNetWorkStartTesting{ //有网络 if(AFNetworkReachabilityManager.sharedManager.networkReachabilityStatus != AFNetworkReachabilityStatusNotReachable) { //关闭网络检测定时器 [self destoryNetWorkStartTesting]; //开始重连 [self reConnectServer]; }}//取消网络检测- (void)destoryNetWorkStartTesting{ WS(weakSelf); dispatch_main_async_safe(^{ if(weakSelf.netWorkTestingTimer) { [weakSelf.netWorkTestingTimer invalidate]; weakSelf.netWorkTestingTimer = nil; } });}//取消心跳- (void)destoryHeartBeat{ WS(weakSelf); dispatch_main_async_safe(^{ if(weakSelf.heartBeatTimer) { [weakSelf.heartBeatTimer invalidate]; weakSelf.heartBeatTimer = nil; } });}//关闭长连接- (void)RMWebSocketClose{ self.isActivelyClose = YES; self.isConnect = NO; self.connectType = WebSocketDefault; if(self.webSocket) { [self.webSocket close]; _webSocket = nil; } //关闭心跳定时器 [self destoryHeartBeat]; //关闭网络检测定时器 [self destoryNetWorkStartTesting];}//发送数据给服务器- (void)sendDataToServer:(NSString *)data{ [self.sendDataArray addObject:data]; //[_webSocket sendString:data error:NULL]; //没有网络 if (AFNetworkReachabilityManager.sharedManager.networkReachabilityStatus == AFNetworkReachabilityStatusNotReachable) { //开启网络检测定时器 [self noNetWorkStartTestingTimer]; } else //有网络 { if(self.webSocket != nil) { // 只有长连接OPEN开启状态才能调 send 方法，不然会Crash if(self.webSocket.readyState == RM_OPEN) {// if (self.sendDataArray.count > 0)// {// NSString *data = self.sendDataArray[0]; [_webSocket sendString:data error:NULL]; //发送数据// [self.sendDataArray removeObjectAtIndex:0];//// } } else if (self.webSocket.readyState == RM_CONNECTING) //正在连接 { DLog(@"正在连接中，重连后会去自动同步数据"); } else if (self.webSocket.readyState == RM_CLOSING || self.webSocket.readyState == RM_CLOSED) //断开连接 { //调用 reConnectServer 方法重连,连接成功后 继续发送数据 [self reConnectServer]; } } else { [self connectServer]; //连接服务器 } }}@end</rmwebsocketdelegate>
注意点
我们在发送消息之前,也就是调用 senderheartBeat/ sendDataToServer:方法之前，一定要判断当前scoket是否连接，如果不是连接状态，程序则会crash。
iOS手机屏幕息屏或者回主页的时候有可能会造成链接断开,我这边的处理是在回到屏幕的时候,判断状态,如果已经断开,就重新连接.
在 AppDelegate 中:
- (void)applicationDidBecomeActive:(UIApplication *)application { // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface. if ([WebSocketManager shared].connectType == WebSocketDisconnect) { [[WebSocketManager shared] connectServer]; }}
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