HTTP协议使用cookie

1、平时浏览访问一个网站时，NSURLRequest都会帮你主动记录下来你访问的站点设置的cookie，当你下次再访问这个站点时，NSURLRequest会拿着上次保存下来了的cookie继续去请求。之前以为手机是不存在cookie的，但是看了一些博客文章，发现其实也能输出cookie的。

<span style="font-size:18px;">//  1.创建一个网络路径
NSURL *url = [NSURL URLWithString:@"http://www.baidu.com"];
// 2.创建一个网络请求
NSURLRequest *request = [NSURLRequest requestWithURL:url
cachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData
timeoutInterval:3];
// 3.获得会话对象
NSURLSession *session = [NSURLSession sharedSession];
// 4.根据会话对象，创建一个Task任务：
NSURLSessionDataTask *sessionDataTask = [session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
//        NSLog(@"从服务器获取到数据");
//
//        /*
//         对从服务器获取到的数据data进行相应的处理：
//         */
//        NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:(NSJSONReadingMutableLeaves) error:nil];

}];

// 5.最后一步，执行任务（resume也是继续执行）:
[sessionDataTask resume];

//输出cookie
NSHTTPCookieStorage *cookieJar = [NSHTTPCookieStorage sharedHTTPCookieStorage];
for (NSHTTPCookie *cookie in [cookieJar cookies]) {
NSLog(@"%@", cookie);
}
</span>

最后会看到控制台输出的cookie内容如下：

<span style="font-size:18px;">2016-06-15 20:34:08.017 cookie[1099:37861] <NSHTTPCookie version:0 name:"BD_NOT_HTTPS" value:"1" expiresDate:2016-06-15 12:29:54 +0000 created:2016-06-15 12:24:54 +0000 sessionOnly:FALSE domain:"www.baidu.com" path:"/" isSecure:FALSE>
2016-06-15 20:34:08.019 cookie[1099:37861] <NSHTTPCookie version:0 name:"BIDUPSID" value:"644741F6E4EB97BB49CD4064752A819F" expiresDate:2084-07-03 15:38:23 +0000 created:2016-06-15 12:24:16 +0000 sessionOnly:FALSE domain:".baidu.com" path:"/" isSecure:FALSE>
2016-06-15 20:34:08.019 cookie[1099:37861] <NSHTTPCookie version:0 name:"PSTM" value:"1465993436" expiresDate:2084-07-03 15:38:23 +0000 created:2016-06-15 12:24:16 +0000 sessionOnly:FALSE domain:".baidu.com" path:"/" isSecure:FALSE>
</span>

2、清空cookie代码

<span style="font-size:18px;">NSHTTPCookieStorage *cookie = [NSHTTPCookieStorage sharedHTTPCookieStorage];
NSArray *_tmpArray = [NSArray arrayWithArray:[cookie cookies]];
for (id obj in _tmpArray) {
[cookieJar deleteCookie:obj];
}</span>

3、设置cookie代码

<span style="font-size:18px;">NSMutableDictionary *cookieProperties = [NSMutableDictionary dictionary];
[cookieProperties setObject:@"username" forKey:NSHTTPCookieName];
[cookieProperties setObject:@"ming" forKey:NSHTTPCookieValue];
[cookieProperties setObject:@"http://write.blog.csdn.net/postlist" forKey:NSHTTPCookieDomain];
[cookieProperties setObject:@"http://write.blog.csdn.net/postlist" forKey:NSHTTPCookieOriginURL];
[cookieProperties setObject:@"/" forKey:NSHTTPCookiePath];
[cookieProperties setObject:@"1" forKey:NSHTTPCookieVersion];

NSHTTPCookie *cookie = [NSHTTPCookie cookieWithProperties:cookieProperties];
[[NSHTTPCookieStorage sharedHTTPCookieStorage] setCookie:cookie];
NSLog(@"%@", cookie);</span>打印输出如下：
<span style="font-size:18px;"><NSHTTPCookie version:1 name:"username" value:"ming" expiresDate:(null) created:2016-06-15 12:40:05 +0000 sessionOnly:TRUE domain:"http://write.blog.csdn.net/postlist" path:"/" isSecure:FALSE></span>