iOS中实现url重定向

以京东为例，展示url重定向

• 测试url：https://www.360buy.com

重定向对应的HTTP状态码

• 301
  • 代表永久转移(Permanently Moved)
  • 涉及到网址修改的，就需要使用301（如京东的的网址修改），网址更改后对搜索引擎友好的处理方法
• 302
  • 代表临时转移(Temporarily Moved )
  • 重定向只是临时性转移，只是临时跳转，而不是永久的更改

iOS中实现url重定向的两种方法

NSURLSession实现url重定向（推荐）

• 代码实现

#import "ViewController.h"

@interface ViewController ()<NSURLSessionTaskDelegate>

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    [self requestByURLSession];
}

- (void)requestByURLSession {
    NSURL *url = [NSURL URLWithString:@"https://www.360buy.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(@"请求成功后的回调===>\nstatus Code: %ld\nHeader Fields: \n%@", urlResponse.statusCode, urlResponse.allHeaderFields);
                                  }];
    [task resume];
}

#pragma mark - NSURLSessionTaskDelegate
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task willPerformHTTPRedirection:(NSHTTPURLResponse *)response newRequest:(NSURLRequest *)request completionHandler:(void (^)(NSURLRequest * __nullable))completionHandler
{
    NSDictionary *headers = response.allHeaderFields;
    // 获取重定向后请求地址的两种方式：headers[@"Location"] 和 [request URL]
    NSLog(@"请求重定向回调===>\nstatus Code: %ld\nHeader Fields: \n%@\n重定向【前】的请求地址: %@\n重定向【后】的请求地址: %@\n", response.statusCode, headers, [response URL], [request URL]);

    completionHandler(request);
//    completionHandler(nil);// 通过设置参数为nil，可以【禁止/拦截】重定向
}

@end

• 测试结果如下图：

  
  
  NSURLSession实现url重定向（推荐）

NSURLConnection实现url重定向

• 代码实现

#import "ViewController.h"

@interface ViewController ()<NSURLConnectionDataDelegate>

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    [self requestByURLConnection];
}

- (void)requestByURLConnection {
    NSURL *url = [NSURL URLWithString:@"https://www.360buy.com"];
    NSMutableURLRequest *quest = [NSMutableURLRequest requestWithURL:url];
    quest.HTTPMethod = @"GET";

    NSURLConnection *connect = [NSURLConnection connectionWithRequest:quest delegate:self];
    [connect start];
}

#pragma mark - NSURLConnectionDataDelegate
- (nullable NSURLRequest *)connection:(NSURLConnection *)connection willSendRequest:(NSURLRequest *)request redirectResponse:(nullable NSURLResponse *)response
{
    NSHTTPURLResponse *urlResponse = (NSHTTPURLResponse *)response;
    NSDictionary *headers = urlResponse.allHeaderFields;
    NSLog(@"请求重定向回调===>\nstatus Code: %ld\nHeader Fields: \n%@\n重定向【前】的请求地址: %@\n重定向【后】的请求地址: %@\n", urlResponse.statusCode, headers, [urlResponse URL], [request URL]);

    return request;
}

@end

• 测试结果如下图：

  
  
  NSURLConnection实现url重定向