The resource could not be loaded because the App Transport Security policy requires the use of a secure connection

xmpp 项目中遇到的问题，用苹果的通信API 写一个PUT 方法，向服务器上传一张图片。遇到如题问题。

Plist 文件没有NSAppTransportSecurity属性 Dic，添加该属性，再添加二级属性NSAllowsArbitraryLoads BOOL  YES

苹果文档：https://developer.apple.com/library/ios/documentation/General/Reference/InfoPlistKeyReference/Articles/CocoaKeys.html

stackOverflow:http://stackoverflow.com/questions/32631184/the-resource-could-not-be-loaded-because-the-app-transport-security-policy-requi

工具类：HTTPTool.h

 #import <Foundation/Foundation.h>

 typedef void (^HttpToolProgressBlock)(CGFloat progress);
 typedef void (^HttpToolCompletionBlock)(NSError *error);

 @interface HttpTool : NSObject

 -(void)uploadData:(NSData *)data
               url:(NSURL *)url
     progressBlock : (HttpToolProgressBlock)progressBlock
             completion:(HttpToolCompletionBlock) completionBlock;

 /**
  下载数据
  */
 -(void)downLoadFromURL:(NSURL *)url
         progressBlock : (HttpToolProgressBlock)progressBlock
             completion:(HttpToolCompletionBlock) completionBlock;

 -(NSString *)fileSavePath:(NSString *)fileName;

 @end

HTTPTool.m

 #import "HttpTool.h"

 #define kTimeOut 5.0

 @interface HttpTool()<NSURLSessionDownloadDelegate,NSURLSessionTaskDelegate>{

     //下载
     HttpToolProgressBlock _dowloadProgressBlock;
     HttpToolCompletionBlock _downladCompletionBlock;
     NSURL *_downloadURL;

     //上传
     HttpToolProgressBlock _uploadProgressBlock;
     HttpToolCompletionBlock _uploadCompletionBlock;

 }

 @end

 @implementation HttpTool

 #pragma mark - 上传
 -(void)uploadData:(NSData *)data url:(NSURL *)url progressBlock:(HttpToolProgressBlock)progressBlock completion:(HttpToolCompletionBlock)completionBlock{

     NSAssert(data != nil, @"上传数据不能为空");
     NSAssert(url != nil, @"上传文件路径不能为空");

     _uploadProgressBlock = progressBlock;
     _uploadCompletionBlock = completionBlock;

     NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:kTimeOut];
     request.HTTPMethod = @"PUT";

     NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration];

     //NSURLSessionDownloadDelegate
     NSURLSession *session = [NSURLSession sessionWithConfiguration:config delegate:self delegateQueue:[[NSOperationQueue alloc] init]];

     //定义下载操作
     NSURLSessionUploadTask *uploadTask = [session uploadTaskWithRequest:request fromData:data];

     [uploadTask resume];
 }

 #pragma mark - 上传代理

 #pragma mark - 上传进度
 -(void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didSendBodyData:(int64_t)bytesSent totalBytesSent:(int64_t)totalBytesSent totalBytesExpectedToSend:(int64_t)totalBytesExpectedToSend{

     if (_uploadProgressBlock) {
         CGFloat progress = (CGFloat) totalBytesSent / totalBytesExpectedToSend;
         _uploadProgressBlock(progress);
     }
 }

 #pragma mark - 上传完成
 -(void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error{
     if (_uploadCompletionBlock) {
         _uploadCompletionBlock(error);

         _uploadProgressBlock = nil;
         _uploadCompletionBlock = nil;
     }
 }

 #pragma mark - 下载
 -(void)downLoadFromURL:(NSURL *)url
          progressBlock:(HttpToolProgressBlock)progressBlock
             completion:(HttpToolCompletionBlock)completionBlock{

     NSAssert(url != nil, @"下载URL不能传空");

     _downloadURL = url;
     _dowloadProgressBlock = progressBlock;
     _downladCompletionBlock = completionBlock;

     NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:kTimeOut];

     //session 大多数使用单例即可

     NSURLResponse *response = nil;

     //发达同步请求
     [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:nil];

     //NSLog(@"%lld",response.expectedContentLength);
     if (response.expectedContentLength <= ) {
         if (_downladCompletionBlock) {
             NSError *error =[NSError errorWithDomain:@"文件不存在" code: userInfo:nil];
             _downladCompletionBlock(error);

             //清除block
             _downladCompletionBlock = nil;
             _dowloadProgressBlock = nil;
         }

         return;
     }

     NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration];

     //NSURLSessionDownloadDelegate
     NSURLSession *session = [NSURLSession sessionWithConfiguration:config delegate:self delegateQueue:[[NSOperationQueue alloc] init]];

     //定义下载操作
     NSURLSessionDownloadTask *downloadTask = [session downloadTaskWithRequest:request];

     [downloadTask resume];

 }

 #pragma mark -NSURLSessionDownloadDelegate
 #pragma mark 下载完成
 -(void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didFinishDownloadingToURL:(NSURL *)location{

     //图片保存在沙盒的Doucument下
     NSString *fileSavePath = [self fileSavePath:[_downloadURL lastPathComponent]];

     //文件管理
     NSFileManager *fileManager = [NSFileManager defaultManager];
     [fileManager copyItemAtURL:location toURL:[NSURL fileURLWithPath:fileSavePath] error:nil];

     if (_downladCompletionBlock) {
         //通知下载成功，没有没有错误
         _downladCompletionBlock(nil);

         //清空block
         _downladCompletionBlock = nil;
         _dowloadProgressBlock = nil;
     }

 }

 #pragma mark 下载进度
 -(void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didWriteData:(int64_t)bytesWritten totalBytesWritten:(int64_t)totalBytesWritten totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite{

     if (_dowloadProgressBlock) {
         //已写数据字节数除以总字节数就是下载进度
         CGFloat progress = (CGFloat)totalBytesWritten / totalBytesExpectedToWrite;

         _dowloadProgressBlock(progress);

     }
 }

 -(void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didResumeAtOffset:(int64_t)fileOffset expectedTotalBytes:(int64_t)expectedTotalBytes{

 }

 #pragma mark -传一个文件名，返回一个在沙盒Document下的文件路径
 -(NSString *)fileSavePath:(NSString *)fileName{
     NSString *document = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[];
     //图片保存在沙盒的Doucument下
     return [document stringByAppendingPathComponent:fileName];
 }

 @end