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 <= 0) {
        if (_downladCompletionBlock) {
            NSError *error =[NSError errorWithDomain:@"文件不存在" code:404 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)[0];
    //图片保存在沙盒的Doucument下
    return [document stringByAppendingPathComponent:fileName];
}

@end