ios – 缓存无法使用自定义NSURLProtocol

2023年5月12日 184次阅读

我正在尝试为NSURLProtocol创建一个子类.但是,我注意到,当我注册我的子类时,我似乎失去了缓存功能,即使它不应该做任何事情.例如,如果我在不注册子类的情况下多次[NSURLConnection sendSynchronousRequest …]到同一个URL,它只执行一个实际的http请求.注册此子类后,它每次都会执行网络请求.

这是我的代码：

@interface CustomURLProtocol : NSURLProtocol
@property (nonatomic, strong) NSURLConnection *connection;
@end

@implementation CustomURLProtocol

+ (BOOL)canInitWithRequest:(NSURLRequest *)request {
    return [[[request URL] scheme] isEqualToString:@"http"] &&
           [NSURLProtocol propertyForKey:@"tagged" inRequest:request] == nil;
}

+ (NSURLRequest *)canonicalRequestForRequest:(NSURLRequest *)request {
    return request;
}

- (void)startLoading {
    NSMutableURLRequest *newRequest = [self.request mutableCopy];
    [NSURLProtocol setProperty:@YES forKey:@"tagged" inRequest:newRequest];
    self.connection = [NSURLConnection connectionWithRequest:newRequest delegate:self];
}

- (void)stopLoading {
    [self.connection cancel];
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [[self client] URLProtocol:self didLoadData:data];
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    [[self client] URLProtocol:self didFailWithError:error];
    self.connection = nil;
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
    [[self client] URLProtocol:self didReceiveResponse:response cacheStoragePolicy:[[self request] cachePolicy]];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection  {
    [[self client] URLProtocolDidFinishLoading:self];
    self.connection = nil;
}
@end

最佳答案 这里的问题不是我的预期.真正的问题是重定向没有得到正确处理,因为以下代码不存在：

- (NSURLRequest *)connection:(NSURLConnection *)connection willSendRequest:(NSURLRequest *)request redirectResponse:(NSURLResponse *)response {
  [[self client] URLProtocol:self wasRedirectedToRequest:request redirectResponse:response];
  return request;
}

如果没有此代码,重定向不会被缓存,因此请求对wikipedia.com等重定向URL的顺序请求每次都会导致重定向.

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