在Objective C中使用NSURLConnection解析json时获取服务器错误消息

NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
    // 接收到服务器响应时的处理
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    // 接收到数据时的处理
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    // 请求完成时的处理
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    // 请求失败时的处理
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    NSString *errorMessage = [error localizedDescription];
    NSLog(@"服务器错误消息：%@", errorMessage);
}