WebSocket 是 HTML5 一種新的協議。它實現了瀏覽器與服務器全雙工通信，能更好的節省服務器資源和帶寬并達到實時通訊，它建立在 TCP 之上，同 HTTP 一樣通過 TCP 來傳輸數據，但是它和 HTTP 最大不同是：WebSocket 是一種雙向通信協議.
由于項目需要創建一個聊天室,需要通過長鏈接,和后臺保持通訊,進行聊天,并且實時進行熱點消息的推送.
目前Facebook的SocketRocket應該是目前最好的關于SocketRocket使用的框架了.而且簡單易用.
使用
一般一個項目在啟動后的某個時機會啟動創建一個長鏈接,如果需要多個就多次創建.如果只要一個就可以封裝為一個單例,全局使用.
可以使用podpod管理庫, 在podfile中加入
pod 'SocketRocket'
在使用命令行工具cd到當前工程 安裝
pod install
導入頭文件后即可使用.
為求穩定,我的做法是copy的FaceBook里SocketRocket庫到項目里. --> SocketRocket地址
1.首先創建一個名為 WebSocketManager 的單例類,
+(instancetype)shared;
2.創建一個枚舉,分別表示WebSocket的鏈接狀態
typedef NS_ENUM(NSUInteger,WebSocketConnectType){ WebSocketDefault = 0, //初始狀態,未連接,不需要重新連接 WebSocketConnect, //已連接 WebSocketDisconnect //連接后斷開,需要重新連接};3.創建連接
//建立長連接- (void)connectServer;
4.處理連接成功的結果;
-(void)webSocketDidOpen:(RMWebSocket *)webSocket; //連接成功回調
5.處理連接失敗的結果
- (void)webSocket:(SRWebSocket *)webSocket didFailWithError:(NSError *)error;//連接失敗回調
6.接收消息
///接收消息回調,需要提前和后臺約定好消息格式.- (void)webSocket:(SRWebSocket *)webSocket didReceiveMessageWithString:(nonnull NSString *)string
7.關閉連接
- (void)webSocket:(SRWebSocket *)webSocket didCloseWithCode:(NSInteger)code reason:(NSString *)reason wasClean:(BOOL)wasClean;///關閉連接回調的代理
8.為保持長鏈接的連接狀態,需要定時向后臺發送消息,就是俗稱的:心跳包.
需要創建一個定時器,固定時間發送消息.
9.鏈接斷開情況處理:
首先判斷是否是主動斷開,如果是主動斷開就不作處理.
如果不是主動斷開鏈接,需要做重新連接的邏輯.
具體代碼如下:
WebSocketManager.h 中的代碼
#import <foundation foundation="" h=""> #import "RMWebSocket.h"typedef NS_ENUM(NSUInteger,WebSocketConnectType){ WebSocketDefault = 0, //初始狀態,未連接 WebSocketConnect, //已連接 WebSocketDisconnect //連接后斷開};@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; //是否連接@property (nonatomic, assign) WebSocketConnectType connectType;+(instancetype)shared;- (void)connectServer;//建立長連接- (void)reConnectServer;//重新連接- (void)RMWebSocketClose;//關閉長連接- (void)sendDataToServer:(NSString *)data;//發送數據給服務器@endNS_ASSUME_NONNULL_END </websocketmanagerdelegate> </nsobject></foundation>WebSocketManager.m 中的代碼
#import "WebSocketManager.h"@interface WebSocketManager ()<rmwebsocketdelegate> @property (nonatomic, strong) NSTimer *heartBeatTimer; //心跳定時器@property (nonatomic, strong) NSTimer *netWorkTestingTimer; //沒有網絡的時候檢測網絡定時器@property (nonatomic, assign) NSTimeInterval reConnectTime; //重連時間@property (nonatomic, strong) NSMutableArray *sendDataArray; //存儲要發送給服務端的數據@property (nonatomic, assign) BOOL isActivelyClose; //用于判斷是否主動關閉長連接，如果是主動斷開連接，連接失敗的代理中，就不用執行 重新連接方法@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;}//建立長連接- (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///開始連接-(void)webSocketDidOpen:(RMWebSocket *)webSocket{ NSLog(@"socket 開始連接"); self.isConnect = YES; self.connectType = WebSocketConnect; [self initHeartBeat];///開始心跳 }///連接失敗-(void)webSocket:(RMWebSocket *)webSocket didFailWithError:(NSError *)error{ NSLog(@"連接失敗"); self.isConnect = NO; self.connectType = WebSocketDisconnect; DLog(@"連接失敗，這里可以實現掉線自動重連，要注意以下幾點"); DLog(@"1.判斷當前網絡環境，如果斷網了就不要連了，等待網絡到來，在發起重連"); DLog(@"3.連接次數限制，如果連接失敗了，重試10次左右就可以了"); //判斷網絡環境 if (AFNetworkReachabilityManager.sharedManager.networkReachabilityStatus == AFNetworkReachabilityStatusNotReachable){ //沒有網絡 [self noNetWorkStartTestingTimer];//開啟網絡檢測定時器 }else{ //有網絡 [self reConnectServer];//連接失敗就重連 }}///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]; }}///關閉連接-(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(@"被關閉連接，code:%ld,reason:%@,wasClean:%d",code,reason,wasClean); [self destoryHeartBeat]; //斷開連接時銷毀心跳 //判斷網絡環境 if (AFNetworkReachabilityManager.sharedManager.networkReachabilityStatus == AFNetworkReachabilityStatusNotReachable){ //沒有網絡 [self noNetWorkStartTestingTimer];//開啟網絡檢測 }else{ //有網絡 NSLog(@"關閉連接"); _webSocket = nil; [self reConnectServer];//連接失敗就重連 }}///ping-(void)webSocket:(RMWebSocket *)webSocket didReceivePong:(NSData *)pongData{ NSLog(@"接受pong數據--> %@",pongData);}#pragma mark - NSTimer//初始化心跳- (void)initHeartBeat{ //心跳沒有被關閉 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]; }) }//重新連接- (void)reConnectServer{ if(self.webSocket.readyState == RM_OPEN){ return; } if(self.reConnectTime > 1024){ //重連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(@"正在重連......"); if(weakSelf.reConnectTime == 0){ //重連時間2的指數級增長 weakSelf.reConnectTime = 2; }else{ weakSelf.reConnectTime *= 2; } }); }//發送心跳- (void)senderheartBeat{ //和服務端約定好發送什么作為心跳標識，盡可能的減小心跳包大小 WS(weakSelf); dispatch_main_async_safe(^{ if(weakSelf.webSocket.readyState == RM_OPEN){ [weakSelf sendPing:nil]; } });}//沒有網絡的時候開始定時 -- 用于網絡檢測- (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]; });}//定時檢測網絡- (void)noNetWorkStartTesting{ //有網絡 if(AFNetworkReachabilityManager.sharedManager.networkReachabilityStatus != AFNetworkReachabilityStatusNotReachable) { //關閉網絡檢測定時器 [self destoryNetWorkStartTesting]; //開始重連 [self reConnectServer]; }}//取消網絡檢測- (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; } });}//關閉長連接- (void)RMWebSocketClose{ self.isActivelyClose = YES; self.isConnect = NO; self.connectType = WebSocketDefault; if(self.webSocket) { [self.webSocket close]; _webSocket = nil; } //關閉心跳定時器 [self destoryHeartBeat]; //關閉網絡檢測定時器 [self destoryNetWorkStartTesting];}//發送數據給服務器- (void)sendDataToServer:(NSString *)data{ [self.sendDataArray addObject:data]; //[_webSocket sendString:data error:NULL]; //沒有網絡 if (AFNetworkReachabilityManager.sharedManager.networkReachabilityStatus == AFNetworkReachabilityStatusNotReachable) { //開啟網絡檢測定時器 [self noNetWorkStartTestingTimer]; } else //有網絡 { if(self.webSocket != nil) { // 只有長連接OPEN開啟狀態才能調 send 方法，不然會Crash if(self.webSocket.readyState == RM_OPEN) {// if (self.sendDataArray.count > 0)// {// NSString *data = self.sendDataArray[0]; [_webSocket sendString:data error:NULL]; //發送數據// [self.sendDataArray removeObjectAtIndex:0];//// } } else if (self.webSocket.readyState == RM_CONNECTING) //正在連接 { DLog(@"正在連接中，重連后會去自動同步數據"); } else if (self.webSocket.readyState == RM_CLOSING || self.webSocket.readyState == RM_CLOSED) //斷開連接 { //調用 reConnectServer 方法重連,連接成功后 繼續發送數據 [self reConnectServer]; } } else { [self connectServer]; //連接服務器 } }}@end</rmwebsocketdelegate>注意點
我們在發送消息之前,也就是調用 senderheartBeat/ sendDataToServer:方法之前，一定要判斷當前scoket是否連接，如果不是連接狀態，程序則會crash。
iOS手機屏幕息屏或者回主頁的時候有可能會造成鏈接斷開,我這邊的處理是在回到屏幕的時候,判斷狀態,如果已經斷開,就重新連接.
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]; }}以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持VEVB武林網。
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