阿里云 OSS 上传&下载文件。iOS 7+

EOTAliyunOSSClient.h

EOTEXTERN NSString * const EOTAliyunOSSClientErrorDomain;

@interface EOTAliyunOSSClient : NSObject

+ (instancetype)sharedClient;

- (void)getObjectWithPath:(NSString *)path
                 inBucket:(EOTCloudStorageBucketType)bucket
                  success:(void (^)(NSData *responseData))success
                  failure:(void (^)(NSError *error))failure;

- (void)postObjectWithData:(NSData *)data
           destinationPath:(NSString *)destinationPath
                  toBucket:(EOTCloudStorageBucketType)bucket
                   success:(void (^)())success
                   failure:(void (^)(NSError *error))failure;

- (void)postObjectWithFile:(NSString *)path
           destinationPath:(NSString *)destinationPath
                  toBucket:(EOTCloudStorageBucketType)bucket
                   success:(void (^)())success
                   failure:(void (^)(NSError *error))failure;

@end

EOTAliyunOSSClient.m

#import "EOTAliyunOSSClient.h"

#import <CommonCrypto/CommonHMAC.h>

NSString * const EOTAliyunOSSClientErrorDomain = @"com.eastopentech.spofie.aliyunoss.error";

NSString * const EOTAliyunOSSHangzhouRegion = @"oss-cn-hangzhou.aliyuncs.com";

// From https://github.com/AFNetworking/AFAmazonS3Client/blob/master/AFAmazonS3Client/AFAmazonS3RequestSerializer.m#L37
static NSData * EOTHMACSHA1EncodedDataFromStringWithKey(NSString *string, NSString *key) {
    NSData *data = [string dataUsingEncoding:NSASCIIStringEncoding];
    CCHmacContext context;
    const char *keyCString = [key cStringUsingEncoding:NSASCIIStringEncoding];
    
    CCHmacInit(&context, kCCHmacAlgSHA1, keyCString, strlen(keyCString));
    CCHmacUpdate(&context, [data bytes], [data length]);
    
    unsigned char digestRaw[CC_SHA1_DIGEST_LENGTH];
    NSUInteger digestLength = CC_SHA1_DIGEST_LENGTH;
    
    CCHmacFinal(&context, digestRaw);
    
    return [NSData dataWithBytes:digestRaw length:digestLength];
}

static NSString * EOTRFC822FormatStringFromDate(NSDate *date) {
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setTimeZone:[NSTimeZone timeZoneWithName:@"GMT"]];
    [dateFormatter setDateFormat:@"EEE, dd MMM yyyy HH:mm:ss z"];
    [dateFormatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"]];
    
    return [dateFormatter stringFromDate:date];
}

@interface EOTAliyunOSSClient ()
@property (nonatomic, strong) NSURLSession *session;
@property (nonatomic, strong) NSMutableSet *requestCacheSet;
@end

@implementation EOTAliyunOSSClient

- (NSURLSession *)session {
    if (!_session) {
        _session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]];
    }
    return _session;
}

- (NSMutableSet *)requestCacheSet {
    if (!_requestCacheSet) {
        _requestCacheSet = [NSMutableSet set];
    }
    return _requestCacheSet;
}

+ (instancetype)sharedClient {
    static id sharedInstance = nil;
    
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        sharedInstance = [[self alloc] init];
    });
    
    return sharedInstance;
}

- (void)cancelAllRequests {
    [self.session invalidateAndCancel];
}

- (void)getObjectWithPath:(NSString *)path
                 inBucket:(EOTCloudStorageBucketType)bucket
                  success:(void (^)(NSData *responseData))success
                  failure:(void (^)(NSError *error))failure {
    NSParameterAssert(path && ![path eot_isEmpty]);
    NSParameterAssert([EOTCloudStorageManager sharedManager].appKeyID);
    NSParameterAssert([EOTCloudStorageManager sharedManager].appKey);
    
    NSString *bucketName = [[EOTCloudStorageManager sharedManager] bucketNamedWithType:bucket];
    
    NSString *cacheKey = [bucketName stringByAppendingPathComponent:path];
    if ([self.requestCacheSet containsObject:cacheKey]) {
        DDLogDebug(@"重复下载");
        return;
    }
    
    NSError *requestError = nil;
    NSURLRequest *request = [self requestWithMethod:@"GET" filePath:path bucket:bucketName error:&requestError];
    if (!requestError) {
        [self.requestCacheSet addObject:cacheKey];
        NSURLSessionDownloadTask *downloadTask = [self.session downloadTaskWithRequest:request completionHandler:^(NSURL *location, NSURLResponse *response, NSError *error) {
            [self.requestCacheSet removeObject:cacheKey];
            
            NSData *data = [NSData dataWithContentsOfURL:location];
            if (!error && [data length] > 1024) {
                !success ?: success(data);
            }
            else {
                !failure ?: failure(error);
            }
        }];
        
        [downloadTask resume];
    }
    else {
        !failure ?: failure(requestError);
    }
    
}

- (void)postObjectWithData:(NSData *)data
           destinationPath:(NSString *)destinationPath
                  toBucket:(EOTCloudStorageBucketType)bucket
                   success:(void (^)())success
                   failure:(void (^)(NSError *error))failure {
    NSParameterAssert(data);
    NSParameterAssert(destinationPath && ![destinationPath eot_isEmpty]);
    NSParameterAssert([EOTCloudStorageManager sharedManager].appKeyID);
    NSParameterAssert([EOTCloudStorageManager sharedManager].appKey);
    
    NSString *bucketName = [[EOTCloudStorageManager sharedManager] bucketNamedWithType:bucket];
    
    NSString *cacheKey = [bucketName stringByAppendingPathComponent:destinationPath];
    if ([self.requestCacheSet containsObject:cacheKey]) {
        DDLogDebug(@"重复上传");
        return;
    }
    
    NSError *requestError = nil;
    NSURLRequest *request = [self requestWithMethod:@"POST" filePath:destinationPath bucket:bucketName error:&requestError];
    
    if (!requestError) {
        [self.requestCacheSet addObject:cacheKey];
        NSURLSessionUploadTask *uploadTask = [self.session uploadTaskWithRequest:request fromData:data
                                                                               completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
                                                                                   [self.requestCacheSet removeObject:cacheKey];
                                                                                   if (!error) {
                                                                                       !success ?: success();
                                                                                   }
                                                                                   else {
                                                                                       !failure ?: failure(error);
                                                                                   }
                                                                               }];
        [uploadTask resume];
    }
    else {
        !failure ?: failure(requestError);
    }
}

- (void)postObjectWithFile:(NSString *)path
           destinationPath:(NSString *)destinationPath
                  toBucket:(EOTCloudStorageBucketType)bucket
                   success:(void (^)())success
                   failure:(void (^)(NSError *error))failure {
    NSMutableURLRequest *fileRequest = [NSMutableURLRequest requestWithURL:[NSURL fileURLWithPath:path]];
    [fileRequest setCachePolicy:NSURLRequestReturnCacheDataElseLoad];
    
    NSURLResponse *response = nil;
    NSError *fileError = nil;
    NSData *data = [NSURLConnection sendSynchronousRequest:fileRequest returningResponse:&response error:&fileError];
    
    if (data && response) {
        [self postObjectWithData:data destinationPath:destinationPath toBucket:bucket success:success failure:failure];
    }
    else {
        !failure ?: failure(fileError);
    }
}


- (NSURLRequest *)requestWithMethod:(NSString *)method
                           filePath:(NSString *)filePath
                             bucket:(NSString *)bucket
                              error:(NSError *__autoreleasing *)error {
    NSParameterAssert(method);
    NSParameterAssert(filePath);
    
    NSString *URLString = [NSString stringWithFormat:@"http://%@.%@/%@", bucket, EOTAliyunOSSHangzhouRegion, filePath];
    
    NSParameterAssert(URLString);
    
    NSURL *url = [NSURL URLWithString:URLString];
    
    NSParameterAssert(url);
    
    NSMutableURLRequest *mutableRequest = [[NSMutableURLRequest alloc] initWithURL:url];
    mutableRequest.HTTPMethod = method;
    mutableRequest.timeoutInterval = 60.f;
    
    NSString *accessKey = [EOTCloudStorageManager sharedManager].appKeyID;
    NSString *secret = [EOTCloudStorageManager sharedManager].appKey;
    
    if (accessKey && secret) {
        NSString *method = [mutableRequest HTTPMethod];
        NSString *contentMD5 = [mutableRequest valueForHTTPHeaderField:@"Content-MD5"];
        NSString *contentType = [mutableRequest valueForHTTPHeaderField:@"Content-Type"];
        NSString *date = EOTRFC822FormatStringFromDate([NSDate date]);
        NSParameterAssert(date);
        NSString *canonicalizedResource = [NSString stringWithFormat:@"/%@%@", bucket, mutableRequest.URL.path];
        NSParameterAssert(canonicalizedResource);
        
        NSMutableString *mutableString = [NSMutableString string];
        [mutableString appendFormat:@"%@\n", (method) ? method : @""];
        [mutableString appendFormat:@"%@\n", (contentMD5) ? contentMD5 : @""];
        [mutableString appendFormat:@"%@\n", (contentType) ? contentType : @""];
        [mutableString appendFormat:@"%@\n", (date) ? date : @""];
        [mutableString appendFormat:@"%@", canonicalizedResource];
        
        NSData *hmac = EOTHMACSHA1EncodedDataFromStringWithKey(mutableString, secret);
        NSString *signature = [hmac base64EncodedStringWithOptions:0];
        
        NSMutableDictionary *header = [NSMutableDictionary dictionary];
        [header setValue:[NSString stringWithFormat:@"OSS %@:%@", accessKey, signature] forKey:@"Authorization"];
        [header setValue:(date) ? date : @"" forKey:@"Date"];
        mutableRequest.allHTTPHeaderFields = header;
    } else {
        if (error) {
            NSDictionary *userInfo = @{NSLocalizedDescriptionKey: NSLocalizedString(@"Access Key and Secret Required", nil)};
            *error = [[NSError alloc] initWithDomain:EOTAliyunOSSClientErrorDomain code:NSURLErrorUserAuthenticationRequired userInfo:userInfo];
        }
    }
    
    return mutableRequest;
}

@end