IOS AsyncSocket☞TCP链接及使用

在互联网世界中，网络访问是必不可少的一部分，而对于程序员来说，网络编程却是一个比较复杂的存在，特别是socket处理方面。

构造自己的socket连接类：

• 为了简化类库中的内容，隐藏一些不关心的接口方法。
• 对类库做一层封装隔离，以个人习惯的方式呈现使用（可以方便库的更新替换，比如：asi到afn的http 库迁移）

基于以上两个原因，我们使用AsyncSocket封装自己的sokcet connection类。代码如下：

GJAsyncSocket.h:

#import <Foundation/Foundation.h>
#import "AsyncSocket.h"

@protocol GJAsyncSocketDelegate <NSObject>
//连接成功回调
-(void)GJAsyncSocketDelagateDidConnect;
//从服务器接收的数据
- (void)GJAsyncSocketDelagateDidReadData:(NSDictionary *)dic;
@end
@interface GJAsyncSocket : NSObject

@property (nonatomic, strong) AsyncSocket    *socket;       // socket
@property (nonatomic, strong) AsyncSocket    *recvSocket;   //socket地址
@property (nonatomic, copy  ) NSString       *socketHost;   // socket的Host
//socket 端口
@property (nonatomic, assign) UInt16         socketPort;    // socket的prot


@property (nonatomic,weak) id<GJAsyncSocketDelegate> delagate;
+ (ZHAsyncSocket *)sharedInstance;

/*
 * 设置地址和端口
 */
-(void)setHostAndPort:(NSString *)socketHost withPort:(UInt16)socketPort;
/*
 * socket连接
 */
-(void)socketConnectHost;
/*
 * 主动关闭切断socket
 */
-(void)cutOffSocket;
/*
 * 发送数据
 */
-(void)sendData:(NSData *)data withTag:(long)tag;
/*
 * 连接前的自检
 */
-(void)openClient;

@end

GJAsyncSocket.m:

#import "GJAsyncSocket.h"
#import <CommonCrypto/CommonHMAC.h>
#import <SystemConfiguration/SystemConfiguration.h>
#import <netdb.h>
#import <arpa/inet.h>

enum{
    SocketOfflineByServer,//服务器
    SocketOfflineByUser,//用户
};

#define k_DCS_IDENTIFY_FLAG     -10000
#define k_DCS_HEART_FLAG     -10001

@interface GJAsyncSocket()<AsyncSocketDelegate>

@property (nonatomic, strong) NSTimer   *connectTimer; // 计时器

@end

@implementation ZHAsyncSocket

+(ZHAsyncSocket *) sharedInstance
{
    static ZHAsyncSocket *sharedInstace = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        sharedInstace = [[self alloc] init];
      });
    return sharedInstace;
}

-(void)setHostAndPort:(NSString *)socketHost withPort:(UInt16)socketPort {
    self.socketHost = socketHost;
    self.socketPort = socketPort;
}

#pragma mark -  socket连接
-(void)socketConnectHost{
    self.socket  = [[AsyncSocket alloc] initWithDelegate:self];
    NSError *error = nil;
    [self.socket connectToHost:self.socketHost onPort:self.socketPort withTimeout:20 error:&error];
}

#pragma mark -- 连接前的自检
-(void)openClient{
    // 确保断开后再连，如果对一个正处于连接状态的socket进行连接，会出现崩溃
    // 在连接前先进行手动断开
    self.socket.userData = SocketOfflineByUser;
    [self cutOffSocket];
    
    self.socket.userData = SocketOfflineByServer;
    [self socketConnectHost];
}

#pragma mark -  主动关闭切断socket
-(void)cutOffSocket{
//    GJLog(@"关闭socket");
    
    self.socket.userData = SocketOfflineByUser;
    [self.connectTimer invalidate];
    self.connectTimer = nil;
    [self.socket setDelegate:nil];
    [self.socket disconnect];
    self.socket = nil;
}

#pragma mark  - 连接成功回调
-(void)onSocket:(AsyncSocket *)sock didConnectToHost:(NSString *)host port:(UInt16)port
{
//    GJLog(@"连接成功");
    [self.socket readDataWithTimeout:-1 tag:1];
    if (_delagate != nil && [_delagate respondsToSelector:@selector(ZHAsyncSocketDelagateDidConnect)]) {
        [_delagate ZHAsyncSocketDelagateDidConnect];
    }

//    客户端向服务端进行心跳检测
//    [self.connectTimer invalidate];
//    self.connectTimer = nil;
//    self.connectTimer = [NSTimer scheduledTimerWithTimeInterval:2 target:self selector:@selector(longConnectToSocket) userInfo:nil repeats:YES];
//    [self.connectTimer fire];
}

#pragma mark -  客户端建立心跳连接
-(void)longConnectToSocket{
    //连接成功发送身份识别
    NSDictionary *postDict = [[NSDictionary alloc] initWithObjectsAndKeys:@"ping",@"type", nil];
    NSData *postData = [[EncryptionSocketData sharedInstance] EncryptionSocketDataWithDic:postDict];
//    [self sendData:postData withTag:k_DCS_IDENTIFY_FLAG];
    [self.socket writeData:postData withTimeout:10 tag:k_DCS_HEART_FLAG];
}

#pragma mark - 断线处理
-(void)onSocketDidDisconnect:(AsyncSocket *)sock
{
    NSLog(@"sorry the connect is failure %ld",sock.userData);
    if (sock.userData == SocketOfflineByServer) {
        // 服务器掉线，重连
        [self socketConnectHost];
    }else if (sock.userData == SocketOfflineByUser) {
        // 如果由用户断开，不进行重连
        GJLog(@"用户断开");
        return;
    }
}

- (void)onSocket:(AsyncSocket *)sock willDisconnectWithError:(NSError *)err
{
    GJLog(@"Socket链接发生了错误,错误操作者:%ld--错误代码%ld",sock.userData,err.code);
}

#pragma mark - 接收数据
-(void)onSocket:(AsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag
{
    // 对得到的data值进行解析与转换即可
    [self.socket readDataWithTimeout:-1 tag:tag];
    NSError *err;
    NSDictionary *dic = [NSJSONSerialization JSONObjectWithData: data
                                                        options:NSJSONReadingMutableContainers
                                                          error:&err];
    GJLog(@"socket收到的数据data = %@",dic);

    if (_delagate != nil && [_delagate respondsToSelector:@selector(ZHAsyncSocketDelagateDidReadData:)]) {
       [_delagate GJAsyncSocketDelagateDidReadData:dic];
    }
}

#pragma mark - 发送数据
-(void)sendData:(NSData *)data withTag:(long)tag {
//    GJLog(@"发送数据");
    [self.socket writeData:data withTimeout:-1 tag:tag];
}

#pragma mark - 已经发送完成数据
-(void)onSocket:(AsyncSocket *)sock didWriteDataWithTag:(long)tag
{
//     GJLog(@"我已经完成数据");
}

-(void)onSocket:(AsyncSocket *)sock didAcceptNewSocket:(AsyncSocket *)newSocket
{
    //接受数据,死循环
    [newSocket readDataWithTimeout:-1 tag:100];
//    GJLog(@"接受数据,死循环");
}

@end

注:下一篇文章我会写到关于AsyncSocket☞TCP粘包与断包的问题的简单解决方案,喜欢的请关注一下我的简书:
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未完待续...