iOS WebSocket長鏈接的實現(xiàn)方法

更新時間：2018年11月01日 13:46:36 作者：suiling

WebSocket是HTML5一種新的協(xié)議，它實現(xiàn)了瀏覽器與服務(wù)器全雙工通信，本篇文章介紹了iOS WebSocket長鏈接的使用，有一定的參考價值，感興趣的小伙伴們可以參考一下

WebSocket

WebSocket 是 HTML5 一種新的協(xié)議。它實現(xiàn)了瀏覽器與服務(wù)器全雙工通信，能更好的節(jié)省服務(wù)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(shù)據(jù)，但是它和 HTTP 最大不同是：WebSocket 是一種雙向通信協(xié)議.

由于項目需要創(chuàng)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(yīng)該是目前最好的關(guān)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(chuàng)建一個長鏈接,如果需要多個就多次創(chuàng)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(dāng)前工程安裝

pod install

導(dǎo)入頭文件后即可使用.

為求穩(wěn)定,我的做法是copy的FaceBook里SocketRocket庫到項目里. --> SocketRocket地址

1.首先創(chuàng)建一個名為 WebSocketManager 的單例類,

+(instancetype)shared;

2.創(chuàng)建一個枚舉,分別表示W(wǎng)ebSocket的鏈接狀態(tài)

typedef NS_ENUM(NSUInteger,WebSocketConnectType){
  WebSocketDefault = 0,  //初始狀態(tài),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(chuàng)建連接

//建立長連接
- (void)connectServer;

4.處理連接成功的結(jié)果;

-(void)webSocketDidOpen:(RMWebSocket *)webSocket; //連接成功回調(diào)

5.處理連接失敗的結(jié)果

- (void)webSocket:(SRWebSocket *)webSocket didFailWithError:(NSError *)error;//連接失敗回調(diào)

6.接收消息

///接收消息回調(diào),需要提前和后臺約定好消息格式.
- (void)webSocket:(SRWebSocket *)webSocket didReceiveMessageWithString:(nonnull NSString *)string

7.關(guān)閉連接

- (void)webSocket:(SRWebSocket *)webSocket didCloseWithCode:(NSInteger)code reason:(NSString *)reason wasClean:(BOOL)wasClean;///關(guān)閉連接回調(diào)的代理

8.為保持長鏈接的連接狀態(tài),需要定時向后臺發(fā)送消息,就是俗稱的:心跳包.

需要創(chuàng)建一個定時器,固定時間發(fā)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(tài),未連接
  WebSocketConnect,   //已連接
  WebSocketDisconnect  //連接后斷開
};
@class WebSocketManager;
@protocol WebSocketManagerDelegate 
 <nsobject>
 
- (void)webSocketManagerDidReceiveMessageWithString:(NSString *)string;
@end
NS_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(guān)閉長連接
- (void)sendDataToServer:(NSString *)data;//發(fā)送數(shù)據(jù)給服務(wù)器
@end
NS_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(wǎng)絡(luò)的時候檢測網(wǎng)絡(luò)定時器
@property (nonatomic, assign) NSTimeInterval reConnectTime; //重連時間
@property (nonatomic, strong) NSMutableArray *sendDataArray; //存儲要發(fā)送給服務(wù)端的數(shù)據(jù)
@property (nonatomic, assign) BOOL isActivelyClose;  //用于判斷是否主動關(guān)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(zhí)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(xiàn)掉線自動重連，要注意以下幾點");
  DLog(@"1.判斷當(dāng)前網(wǎng)絡(luò)環(huán)境，如果斷網(wǎng)了就不要連了，等待網(wǎng)絡(luò)到來，在發(fā)起重連");
  DLog(@"3.連接次數(shù)限制，如果連接失敗了，重試10次左右就可以了");
  
  //判斷網(wǎng)絡(luò)環(huán)境
  if (AFNetworkReachabilityManager.sharedManager.networkReachabilityStatus == AFNetworkReachabilityStatusNotReachable){ //沒有網(wǎng)絡(luò)
  
    [self noNetWorkStartTestingTimer];//開啟網(wǎng)絡(luò)檢測定時器
  }else{ //有網(wǎng)絡(luò)
  
    [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(guān)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(guān)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(wǎng)絡(luò)環(huán)境
  if (AFNetworkReachabilityManager.sharedManager.networkReachabilityStatus == AFNetworkReachabilityStatusNotReachable){ //沒有網(wǎng)絡(luò)
    [self noNetWorkStartTestingTimer];//開啟網(wǎng)絡(luò)檢測
  }else{ //有網(wǎng)絡(luò)
    NSLog(@"關(guān)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(shù)據(jù)--> %@",pongData);
}
#pragma mark - NSTimer
//初始化心跳
- (void)initHeartBeat{
  //心跳沒有被關(guān)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(shù)級增長
      weakSelf.reConnectTime = 2;
    }else{
      weakSelf.reConnectTime *= 2;
    }
  });
  
}
//發(fā)送心跳
- (void)senderheartBeat{
  //和服務(wù)端約定好發(fā)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(wǎng)絡(luò)的時候開始定時 -- 用于網(wǎng)絡(luò)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(wǎng)絡(luò)
- (void)noNetWorkStartTesting{
  //有網(wǎng)絡(luò)
  if(AFNetworkReachabilityManager.sharedManager.networkReachabilityStatus != AFNetworkReachabilityStatusNotReachable)
  {
    //關(guān)閉網(wǎng)絡(luò)檢測定時器
    [self destoryNetWorkStartTesting];
    //開始重連
    [self reConnectServer];
  }
}
//取消網(wǎng)絡(luò)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(guān)閉長連接
- (void)RMWebSocketClose{
  self.isActivelyClose = YES;
  self.isConnect = NO;
  self.connectType = WebSocketDefault;
  if(self.webSocket)
  {
    [self.webSocket close];
    _webSocket = nil;
  }
  
  //關(guān)閉心跳定時器
  [self destoryHeartBeat];
  
  //關(guān)閉網(wǎng)絡(luò)檢測定時器
  [self destoryNetWorkStartTesting];
}
//發(fā)送數(shù)據(jù)給服務(wù)器
- (void)sendDataToServer:(NSString *)data{
  [self.sendDataArray addObject:data];
  
  //[_webSocket sendString:data error:NULL];
  
  //沒有網(wǎng)絡(luò)
  if (AFNetworkReachabilityManager.sharedManager.networkReachabilityStatus == AFNetworkReachabilityStatusNotReachable)
  {
    //開啟網(wǎng)絡(luò)檢測定時器
    [self noNetWorkStartTestingTimer];
  }
  else //有網(wǎng)絡(luò)
  {
    if(self.webSocket != nil)
    {
      // 只有長連接OPEN開啟狀態(tài)才能調(diào) 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(fā)送數(shù)據(jù)
//          [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(shù)據(jù)");
      }
      else if (self.webSocket.readyState == RM_CLOSING || self.webSocket.readyState == RM_CLOSED) //斷開連接
      {
        //調(diào)用 reConnectServer 方法重連,連接成功后 繼續(xù)發(fā)送數(shù)據(jù)
        [self reConnectServer];
      }
    }
    else
    {
      [self connectServer]; //連接服務(wù)器
    }
  }
}
@end
</rmwebsocketdelegate>

注意點

我們在發(fā)送消息之前,也就是調(diào)用 senderheartBeat/ sendDataToServer:方法之前，一定要判斷當(dāng)前scoket是否連接，如果不是連接狀態(tài)，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(tài),如果已經(jīng)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(nèi)容，希望對大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。

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