檔案下載(NSURLConnection/NSURLSession)

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最基本的網路檔案下載(使用原生的網路請求)

 

#pragma mark - 小檔案下載

 

// 方法一: NSData dataWithContentsOfURL- (void)downloadFile1{    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{        // 其實這就是一個GET請求        NSURL *url = [NSURL URLWithString:@"http://localhost:8080/Server/resources/images/minion_01.png"];        NSData *data = [NSData dataWithContentsOfURL:url];        NSLog(@"%lu", data.length);    });}

 

// 方法二: NSURLConnection- (void)downloadFile2{    NSURL *url = [NSURL URLWithString:@"http://localhost:8080/Server/resources/images/minion_01.png"];    NSURLRequest *request = [NSURLRequest requestWithURL:url];    [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {        NSLog(@"%lu", data.length);    }];}

 

//方法三：NSURLSession iOS7開始出現的 為取代NSURLConnection- (void)downloadFile3{    // 1.得到session對象    NSURLSession *session = [NSURLSession sharedSession];    // 2.建立一個下載task    NSURL *url = [NSURL URLWithString:@"http://localhost:8080/Server/resources/test.mp4"];    NSURLSessionDownloadTask *task = [session downloadTaskWithURL:url completionHandler:^(NSURL *location, NSURLResponse *response, NSError *error) {// location : 臨時檔案的路徑（下載好的檔案）        NSString *caches = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];        // response.suggestedFilename ： 建議使用的檔案名稱，一般跟伺服器端的檔案名稱一致        NSString *file = [caches stringByAppendingPathComponent:response.suggestedFilename];        // 將臨時檔案剪下或者複製Caches檔案夾        NSFileManager *mgr = [NSFileManager defaultManager];        // AtPath : 剪下前的檔案路徑        // ToPath : 剪下後的檔案路徑        [mgr moveItemAtPath:location.path toPath:file error:nil];    }];        // 3.開始任務    [task resume];}

 

 

#pragma mark - 大檔案下載

 

//方法一: NSURLConnection (合理：單個線程 下載一點就寫入一點)使用NSFileHandle//控制代碼對象@property (nonatomic, strong) NSFileHandle * writeHandle;- (void)downloadFile4{    NSURL *url = [NSURL URLWithString:@"http://localhost:8080/Server/resources/videos.zip"];    NSURLRequest *request = [NSURLRequest requestWithURL:url];    // 下載(建立完conn對象後，會自動發起一個非同步請求,通過delegate回調下載資訊)    [NSURLConnection connectionWithRequest:request delegate:self];}#pragma mark - NSURLConnectionDataDelegate- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{//請求失敗}// 1.接收到伺服器的響應就會調用- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{    // 檔案路徑    NSString *caches = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];    NSString *filepath = [caches stringByAppendingPathComponent:@"videos.zip"];    // 建立一個空的檔案 到 沙箱中    NSFileManager *mgr = [NSFileManager defaultManager];    [mgr createFileAtPath:filepath contents:nil attributes:nil];    // 建立一個用來寫資料的檔案控制代碼    self.writeHandle = [NSFileHandle fileHandleForWritingAtPath:filepath];}// 2.當接收到伺服器返回的實體資料時調用（具體內容，這個方法可能會被調用多次）- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{    // 移動到檔案的最後面    [self.writeHandle seekToEndOfFile];    // 將資料寫入沙箱    [self.writeHandle writeData:data];}// 3.載入完畢後調用（伺服器的資料已經接收完畢）- (void)connectionDidFinishLoading:(NSURLConnection *)connection;{    // 關閉檔案 設定為空白    [self.writeHandle closeFile];    self.writeHandle = nil;}

 

//檔案流@property (nonatomic, strong) NSOutputStream * fileStream;//方法二: NSURLConnection 使用NSOutputStream- (void)downloadFile6{    NSURL *url = [NSURL URLWithString:@"http://localhost:8080/Server/resources/videos.zip"];    NSURLRequest *request = [NSURLRequest requestWithURL:url];    // 下載(建立完conn對象後，會自動發起一個非同步請求,通過delegate回調下載資訊)    [NSURLConnection connectionWithRequest:request delegate:self];}#pragma mark - NSURLConnectionDataDelegate- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error{//請求失敗}// 1.接收到伺服器的響應就會調用- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response{    // 檔案路徑    NSString *caches = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];    NSString *filepath = [caches stringByAppendingPathComponent:@"videos.zip"];    // 建立一個空的檔案 到 沙箱中    NSFileManager *mgr = [NSFileManager defaultManager];    [mgr createFileAtPath:filepath contents:nil attributes:nil];    // 建立一個用來寫資料的檔案控制代碼    self.fileStream = [NSOutputStream outputStreamToFileAtPath:filepath append:YES];}// 2.當接收到伺服器返回的實體資料時調用（具體內容，這個方法可能會被調用多次）- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{    //將資料追加到檔案流中    [self.fileStream write:data.bytes maxLength:data.length];}// 3.載入完畢後調用（伺服器的資料已經接收完畢）- (void)connectionDidFinishLoading:(NSURLConnection *)connection;{    // 關閉檔案流    [self.fileStream close];}

 

 

 

 

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檔案下載(NSURLConnection/NSURLSession)