iOS WebSocket长链接的实现方法
作者：suiling
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，本篇文章介绍了iOS WebSocket长链接的使用，有一定的参考价值，感兴趣的小伙伴们可以参考一下
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;
@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
@end
NS_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];
}
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。