How to use android kotlin for download files

App architecture. Architecture Components. UI layer libraries. View binding. Data binding library. Lifecycle-aware components. Paging Library. Paging 2. Data layer libraries. How-To Guides. Advanced Concepts. Threading in WorkManager.

App entry points. App shortcuts. App navigation. Navigation component. App links. Dependency injection. Core topics. App compatibility. Interact with other apps. Package visibility. Intents and intent filters.

User interface. Add motion to your layout with MotionLayout. MotionLayout XML reference. Improving layout performance. Custom view components. Look and feel. Splash screens.

Add the app bar. Control the system UI visibility. Supporting swipe-to-refresh. Pop-up messages overview. Adding search functionality.

Creating backward-compatible UIs. Home channels for mobile apps. App widgets. Media app architecture. Building an audio app.

Building a video app. The Google Assistant. Routing between devices. Background tasks. Manage device awake state. Save to shared storage. Create the instances of these classes instead of FontsContract and android.

FontRequest framework classes. Note : You must provide a certificate when you request fonts through the support library. This is applicable even for the pre-installed font providers. To use the FontsContractCompat and FontRequest classes, you must modify your app project's classpath dependencies within your development environment. This means, there is no need to bundle the font as an asset. You can define a custom font for your entire theme, which accelerates usability for multiple weights and styles, such as Bold, Medium, or Light, when provided.

Layout inflation and resource retrieval are synchronous tasks. By default, the first attempt to retrieve fonts triggers a request to the font provider, and therefore increases the first layout time. To avoid the delay, you can pre-declare fonts that need retrieving in your manifest.

After the system retrieves the font from the provider, it is available immediately. If the font retrieval takes longer than expected, the system aborts the fetching process and uses the default font. When a font provider is not preinstalled or if you are using the support library, you must declare the certificates the font provider is signed with. The system uses the certificates to verify the font provider's identity. Note : Android Studio can automatically populate the values for the Google Play services provider if you use the font selector tool in Android Studio.

Note : If the provider has more than one set of certs, you can define an array of string arrays. Content and code samples on this page are subject to the licenses described in the Content License. App Basics. Build your first app. App resources. Resource types. App manifest file. Device compatibility. Multiple APK support. Tablets, large screens, and foldables.

Build responsive UIs. Build for foldables. Getting started. Handling data. User input. Watch Face Studio. Health services. Creating watch faces. Android TV. Build TV Apps. Build TV playback apps. Help users find content on TV. Recommend TV content. Watch Next. Build TV games. Build TV input services. TV Accessibility. Android for Cars. Build media apps for cars.

Build navigation, parking, and charging apps for cars. Android Things. Supported hardware. Advanced setup. Build apps. Create a Things app. Communicate with wireless devices. Configure devices. Interact with peripherals.

Build user-space drivers. Manage devices. Create a build. We want to download videos using the DownloadManager class in android. We want to give them appropriate names and store them in external storage. First we have been passed the video url as a parameter. Maybe you could use endsWith if you like instead of contains. In this complete example we want to see how to download a file from the internet using the downloadManager class.

Then we can open the donwload by clicking the notification in the system bar or from internally in our app. Moreover we can delete the file, view all downloads etc. MainActivity as you can imagine is our launcher activity. This is where we write all our code. But first we start by making several imports. These include:. As a System service, the DownloadManager is not instantiated directly.

Instead we will initialize it using the getSystemService method and cast the resultant object into the DownloadManager class.

Inside the DownloadManager class is an inner class called the Request class. This check allows your app-side, cached data to stay in sync with the system-side, provider data.

When you perform sequential reads of media files using direct file paths, the performance is comparable to that of the MediaStore API. When you perform random reads and writes of media files using direct file paths, however, the process can be up to twice as slow. When you access an existing media file, you can use the value of the DATA column in your logic. That's because this value has a valid file path. However, don't assume that the file is always available. To create or update a media file, on the other hand, don't use the value of the DATA column.

Apps that target Android 10 or higher can access the unique name that the system assigns to each external storage volume. This naming system helps you efficiently organize and index content, and it gives you control over where new media files are stored. You can discover other volumes by calling MediaStore. Some photographs and videos contain location information in their metadata, which shows the place where a photograph was taken or where a video was recorded. To access this location information in your app, use one API for photograph location information and another API for video location information.

If your app uses scoped storage , the system hides location information by default. To access this information, complete the following steps:. From your MediaStore object, get the exact bytes of the photograph by calling setRequireOriginal and pass in the URI of the photograph, as shown in the following code snippet:.

To access location information within a video's metadata, use the MediaMetadataRetriever class, as shown in the following code snippet. Your app doesn't need to request any additional permissions to use this class. Some apps allow users to share media files with each other. For example, social media apps give users the ability to share photos and videos with friends. When scoped storage is enabled for an app that targets Android 10 or higher, the system attributes an app to each media file, which determines the files that your app can access when it hasn't requested any storage permissions.

Each file can be attributed to only one app. Therefore, if your app creates a media file that's stored in the photos, videos, or audio files media collection, your app has access to the file. This permission request is required because the system considers the file to be attributed to the previously-installed version of the app, rather than the newly-installed one.

To add a media item to an existing collection, call code similar to the following. That's because, on these devices, you can only modify the contents of a volume if it's the primary volume, as described in the storage volumes section.

If your app performs potentially time-consuming operations, such as writing to media files, it's useful to have exclusive access to the file as it's being processed. The following code snippet builds upon the previous code snippet. Audio collection:. When your app stores media on a device running Android 10, the media is organized based on its type by default.

For example, new image files are placed by default in the Environment. Images collection. If scoped storage is unavailable or not enabled, the process shown in the preceding code snippet also works for files that your app doesn't own. If you need to write media files using native libraries, pass the file's associated file descriptor from your Java-based or Kotlin-based code into your native code.

The following code snippet shows how to pass a media object's file descriptor into your app's native code:. If your app uses scoped storage , it ordinarily cannot update a media file that a different app contributed to the media store. It's still possible to get user consent to modify the file, however, by catching the RecoverableSecurityException that the platform throws. You can then request that the user grant your app write access to that specific item, as shown in the following code snippet:.

Alternatively, if your app runs on Android 11 or higher, you can allow users to grant your app write access to a group of media files. Call the createWriteRequest method, as described in the section on how to manage groups of media files. If your app has another use case that isn't covered by scoped storage, file a feature request and temporarily opt out of scoped storage.

To remove an item that your app no longer needs in the media store, use logic similar to what's shown in the following code snippet:.

If scoped storage is unavailable or isn't enabled, you can use the preceding code snippet to remove files that other apps own. If scoped storage is enabled, however, you need to catch a RecoverableSecurityException for each file that your app wants to remove, as described in the section on updating media items.

If your app runs on Android 11 or higher, you can allow users to choose a group of media files to remove. Call the createTrashRequest method or the createDeleteRequest method, as described in the section on how to manage groups of media files. Your app might need to identify storage volumes containing media files that apps added or modified, compared to a previous point in time. To detect these changes most reliably, pass the storage volume of interest into getGeneration. As long as the media store version doesn't change, the return value of this method monotonically increases over time.

That's because those media column values could change when an app calls setLastModified , or when the user changes the system clock. On Android 11 and higher, you can ask the user to select a group of media files, then update these media files in a single operation. These methods offer better consistency across devices, and the methods make it easier for users to manage their media collections.

Request that the user place the specified media files in the device's trash. Items in the trash are permanently deleted after a system-defined time period. Request that the user permanently delete the specified media files immediately, without placing them in the trash beforehand. After calling any of these methods, the system builds a PendingIntent object. After your app invokes this intent, users see a dialog that requests their consent for your app to update or delete the specified media files.

For example, here is how to structure a call to createWriteRequest :. Evaluate the user's response. If the user provided consent, proceed with the media operation. Otherwise, explain to the user why your app needs the permission:. Users might trust a particular app to perform media management, such as making frequent edits to media files. If your app targets Android 12 API level 31 or higher, you can request that users grant your app access to the Media management special permission.

This permission allows your app to do each of the following without needing to prompt the user for each file operation:. In your app, show a UI to the user to explain why they might want to grant media management access to your app.

This takes users to the Media management apps screen in system settings. From here, users can grant the special app access. If your app primarily performs one of the following roles, consider an alternative to the MediaStore APIs. We also recommend this workflow as a security best practice. Content and code samples on this page are subject to the licenses described in the Content License.