Socket 通讯

#import "ViewController.h"

#import <sys/socket.h>

#import <netinet/in.h>

#import <arpa/inet.h>

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UIWebView *webView;

@property (nonatomic, assign) int clientSocket;

@end

@implementation ViewController

//1 连接

- (BOOL)connect:(NSString *)ip port:(int)port{

//1 创建socket

int clientSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

self.clientSocket = clientSocket;

//2 连接到服务器

struct sockaddr_in serverAdd;

serverAdd.sin_family = AF_INET;

serverAdd.sin_port = htons(port);   //16位   底8位   高8位       高8位  低8位

serverAdd.sin_addr.s_addr = inet_addr(ip.UTF8String) ;

int result = connect(clientSocket, (const struct sockaddr *)&serverAdd, sizeof(serverAdd));

if (result == 0) {

NSLog(@"成功");

return YES;

}else{

NSLog(@"失败");

return NO;

}

}

//2 发送http请求和接收http响应

- (NSString *)sendAndRec:(NSString *)request{

//3 发数据

//    第一个参数指定发送端套接字描述符；

//    第二个参数指明一个存放应用程式要发送数据的缓冲区；

//    第三个参数指明实际要发送的数据的字符数；

//    第四个参数一般置0。

//返回实际发送的字节个数

const char *msg = request.UTF8String;

//发送失败  返回-1

//strlen  获取的是字符个数  sizeof获取的是字节数

ssize_t sendLen = send(self.clientSocket, msg, strlen(msg), 0);

NSLog(@"发送的字节个数:%zd",sendLen);

//4 接收数据

char buffer[1024];

//等待服务器返回数据    阻塞

ssize_t recvLen = -1;

//循环接收所有的数据

NSMutableData *mData = [NSMutableData data];

while (recvLen != 0) {

recvLen = recv(self.clientSocket, buffer, sizeof(buffer), 0);

//        NSLog(@"接收到得字节个数:%zd",recvLen);

NSData *data = [NSData dataWithBytes:buffer length:recvLen];

[mData appendData:data];

}

//把字节数组转换成字符串

NSString *str = [[NSString alloc] initWithData:mData encoding:NSUTF8StringEncoding];

//    NSString *str = [NSString stringWithCString:buffer encoding:NSUTF8StringEncoding];

NSLog(@"%@",str);

return str;

}

//3 关闭

- (void)close{

//5 关闭

close(self.clientSocket);

}

- (void)viewDidLoad {

[super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

//1 发送和接收数据

//2 发送什么数据 ,接收的是什么数据 (http的请求和响应)

//http协议中要求

//http协议中的长连接和短连接

//短连接  请求结束后会立即断开

//长连接  当请求结束后,等等待非常短的时间,  如果超过时间没有请求,断开连接

//http请求协议

//请求行

//请求头

//请求体

if ([self connect:@"119.75.218.70" port:80]) {

//发送http请求

NSString *request = @"GET / HTTP/1.0\r\n"

@"Host: www.baidu.com\r\n"

@"User-Agent:Mozilla/5.0 (iPhone; CPU iPhone OS 8_0 like Mac OS X) AppleWebKit/600.1.3 (KHTML, like Gecko) Version/8.0 Mobile/12A4345d Safari/600.1.4\r\n"

@"Connection: close\r\n"

@"\r\n";

NSString *response = [self sendAndRec:request];

NSLog(@"%@",response);

//处理响应的结果

//根据分析的http响应报文.  要通过两个\r\n截取响应体

//1 找到两个\r\n的位置

NSRange range = [response rangeOfString:@"\r\n\r\n"];

//2 从两个\r\n之后开始截取,截取到的最后

NSString *html = [response substringFromIndex:range.location + range.length];

[self.webView loadHTMLString:html baseURL:[NSURL URLWithString:@"http://www.baidu.com"]];

}

}

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@end