iOS 拦截重定向302跳转的方法详解

一：前言

公司同事在做项目的时候遇到一个302地址跳转的问题，具体需求如下:

1、公司是做wifi覆盖的，需要在下载app后才能注册登录以后，自动连接到外网

2、苹果底层不允许我们码农进行wifi的切换，所以公司考虑使用302重定向来实现，我通过2种方法来实现，nsurlconnetion和nsurlsession

二：nsurlconnetion方法

大概的思路:使用nsurlconnetion类的nsurlconnectiondatadelegate中的代理方法

- (nullable nsurlrequest *)connection:(nsurlconnection *)connection willsendrequest:(nsurlrequest *)request redirectresponse:(nullable nsurlresponse *)response

都是码农，直接上代码吧

新建一个demo项目的话，记得把app transport security settings allow arbitrary loads设置为yes，否则无法请求网络

- (void)viewdidload {
  [super viewdidload];
 nsurl *url = [nsurl urlwithstring:@"http://www.google.com"];
  nsmutableurlrequest *quest = [nsmutableurlrequest requestwithurl:url];
  quest.httpmethod = @"get";
  nsurlconnection *connect = [nsurlconnection connectionwithrequest:quest delegate:self];
  [connect start];
}

- (nullable nsurlrequest *)connection:(nsurlconnection *)connection willsendrequest:(nsurlrequest *)request redirectresponse:(nullable nsurlresponse *)response{

  nshttpurlresponse *urlresponse = (nshttpurlresponse *)response;

  nslog(@"%ld",urlresponse.statuscode);
  nslog(@"%@",urlresponse.allheaderfields);
  nsdictionary *dic = urlresponse.allheaderfields;
  nslog(@"%@",dic[@"location"]);
  return request;
}

request 是你要发送的请求 urlresponse.statuscode 则是请求的状态码,302则是重定向 。urlresponse.allheaderfields中保存着http的头信息:

{
  connection = close;
  "content-type" = "text/html";
  date = "mon, 30 may 2016 04:00:49 gmt";
  location = "http://118.244.233.137:6001/login/?gw_address=192.168.17.1&gw_port=2060&gw_id=ctzx_11&ip=192.168.17.24&mac=54:72:4f:30:c6:10&url=http%3a%2f%2fwww.google.com%2f";
  server = "hughes technologies embedded server";
}

通过urlresponse.allheaderfields[@"location"]即可拿到302跳转的url地址.如果需要拦截掉这个url地址跳转，则可在代理方法中自定义一个request

- (void)urlsession:(nsurlsession *)session task:(nsurlsessiontask *)task
willperformhttpredirection:(nshttpurlresponse *)response
    newrequest:(nsurlrequest *)request
 completionhandler:(void (^)(nsurlrequest * __nullable))completionhandler{

  //block为nil，则直接拦截掉302的url地址，防止自动跳转
  completionhandler(nil);

}

则直接拦截掉302的url地址，防止自动跳转 completionhandler(nil);}

三：nsurlsession方法

- (void)viewdidload {
  [super viewdidload];
  nsurl *url = [nsurl urlwithstring:@"http://www.google.com"];
  nsmutableurlrequest *quest = [nsmutableurlrequest requestwithurl:url];
  quest.httpmethod = @"get";
  nsurlsessionconfiguration *config = [nsurlsessionconfiguration defaultsessionconfiguration];
  config.requestcachepolicy = nsurlrequestreloadignoringlocalcachedata;
  nsurlsession *urlsession = [nsurlsession sessionwithconfiguration:config delegate:self delegatequeue:[nsoperationqueue currentqueue]];

  nsurlsessiondatatask *task = [urlsession datataskwithrequest:quest completionhandler:^(nsdata * _nullable data, nsurlresponse * _nullable response, nserror * _nullable error) {

    nshttpurlresponse *urlresponse = (nshttpurlresponse *)response;

    nslog(@"%ld",urlresponse.statuscode);
    nslog(@"%@",urlresponse.allheaderfields);

    nsdictionary *dic = urlresponse.allheaderfields;
    nslog(@"%@",dic[@"location"]);

  }];

  [task resume];

}


- (void)urlsession:(nsurlsession *)session task:(nsurlsessiontask *)task
willperformhttpredirection:(nshttpurlresponse *)response
    newrequest:(nsurlrequest *)request
 completionhandler:(void (^)(nsurlrequest * __nullable))completionhandler{

  completionhandler(nil);

}

使用方法和第一种方法一样

demo下载

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。​