Android download file to external storage

External Storage Availability In order to avoid crashing the app first, we need to check storage SD Card is available for reading and write operations. The method getExternalStorageState is used to determine the state of mounted storage media such as SD Card is missing, read-only or readable, and writable.

Below is the code snippet which we will use to check the availability of external storage. For eg: Images clicked by the camera are still available even after we uninstall the camera. And data are removed as we uninstall the app. It is now absolute and it is used to access external storage in older versions, API Level less than 7.

Example In this example, we would store text data into the external storage and fetch to see that data. A sample GIF is given below to get an idea about what we are going to do in this article. Note that we are going to implement this project using the Java language. Note that select Java as the programming language. These permissions are added to the AndroidManifest. Integrate Android Performance Tuner.

Output audio. Manage memory. Use prebuilt or turnkey game engines. Develop with Defold. Develop with Godot. Develop with Unity. Use Android Performance Tuner. Game best practices. Maximize device availability. Art assets. OpenGL and Vulkan. Game Mode. Best practices.

Building effective unit tests. Automating UI tests. Testing app component integrations. Android Vitals. Optimizing for Battery Life. System tracing. Build and test apps for accessibility. Advanced topics. Protecting against security threats with SafetyNet. Build for Billions. Build for Enterprise. App feedback. Device management. Dedicated devices. Android versions. Android Developers. The system provides several options for you to save your app data: App-specific storage: Store files that are meant for your app's use only, either in dedicated directories within an internal storage volume or different dedicated directories within external storage.

Use the directories within internal storage to save sensitive information that other apps shouldn't access. Shared storage: Store files that your app intends to share with other apps, including media, documents, and other files. Preferences: Store private, primitive data in key-value pairs. Databases: Store structured data in a private database using the Room persistence library.

The characteristics of these options are summarized in the following table: Type of content Access method Permissions needed Can other apps access? Files removed on app uninstall? App-specific files Files meant for your app's use only From internal storage, getFilesDir or getCacheDir From external storage, getExternalFilesDir or getExternalCacheDir Never needed for internal storage Not needed for external storage when your app is used on devices that run Android 4.

Internal storage has limited space for app-specific data. Use other types of storage if you need to save a substantial amount of data. How reliable does data access need to be? If your app's basic functionality requires certain data, such as when your app is starting up, place the data within internal storage directory or a database. App-specific files that are stored in external storage aren't always accessible because some devices allow users to remove a physical device that corresponds to external storage.

What kind of data do you need to store? If you have data that's only meaningful for your app, use app-specific storage. For shareable media content, use shared storage so that other apps can access the content.

For structured data, use either preferences for key-value data or a database for data that contains more than 2 columns. Should the data be private to your app? When storing sensitive data—data that shouldn't be accessible from any other app—use internal storage, preferences, or a database.

Internal storage has the added benefit of the data being hidden from users. Categories of storage locations Android provides two types of physical storage locations: internal storage and external storage. Scoped storage To give users more control over their files and to limit file clutter, apps that target Android 10 API level 29 and higher are given scoped access into external storage, or scoped storage , by default. Additional resources For more information about data storage, consult the following resources.

As an example, for an application with the package name com. The parameter for GetExternalFilesDir is a string that specifies an application directory. This is a directory intended to provide a standard location for a logical organization of files. The string values are available through constants on the Android. Environment class:. For devices that have multiple external storage partitions, each partition will have a directory that is intended for private files.

The method Android. GetExternalFilesDirs string type will return an array of Java. The exact path to the private external storage directory can vary from device to device and between versions of Android.

Because of this, apps must not hard code the path to this directory, and instead use the Xamarin. Android APIs, such as Android. Public files are files that exist on external storage that are not stored in the directory that Android allocates for private files. Public files will not be deleted when the app is uninstalled. Android apps must be granted permission before they can read or write any public files.

It is possible for public files to exist anywhere on external storage, but by convention Android expects public files to exist in the directory identified by the property Android. This property will return a Java. File object that represents the primary external storage directory. As an example, Android. ExternalStorageDirectory may refer to the following directory:. File object that correspond to a public application directory.

The directoryType parameter is a mandatory parameter and cannot be null. For example, calling Environment. AbsolutePath will return a string which will resemble:. The exact path to the public external storage directory can vary from device to device and between versions of Android.

Once a Xamarin. Android app has obtained the full path to a file, it should utilize any of the standard. In case, if we are handling the files that are not intended for other apps to use, then we should use a private storage directory on the external storage by calling getExternalFilesDir.

By using android FileOutputStream object and getExternalStoragePublicDirectory method, we can easily create and write data to the file in external storage public folders. Following is the code snippet to create and write a public file in the device Downloads folder. If you observe above code, we are creating and writing a file in device public Downloads folder by using getExternalStoragePublicDirectory method.

We used write method to write the data in file and used close method to close the stream. By using the android FileInputStream object and getExternalStoragePublicDirectory method, we can easily read the file from external storage.

Following is the code snippet to read data from a file that is in the downloads folder. If you observe above code, we are reading a file from device Downloads folder storage by using FileInputStream object getExternalStoragePublicDirectory method with file name. We used read method to read one character at a time from the file and used close method to close the stream.

Now we will see how to save or write file to external memory and read the file data from external storage using android FileInputStream and FileOutputStream objects in android applications with examples.

Following is the example of storing and retrieving the data files from external memory by using FileOutputStream and FileInputStream objects. Create a new android application using android studio and give names as ExternalStorageExample.