Storage Interactions¶

modernstorage-storage is a library abstracting storage interactions on Android using the library Okio. It relies on its FileSystem API, which provides a set of methods to read and write files.

Instead of opening an InputStream or OutputStream and relies on different APIs to get file metadata for MediaStore and Storage Access Framework DocumentProvider, this library takes Uri (changed to Path to make it work with Okio) as an input for all its methods to read and write files but also get metadata.

Add dependency to project¶

modernstorage-storage is available on mavenCentral().

// build.gradle

// modernstorage-storage requires Okio 3.x.x as a dependency
implementation("com.squareup.okio:okio:3.0.0")
implementation("com.google.modernstorage:modernstorage-storage:1.0.0-alpha06")

API reference¶

modernstorage-storage API reference is available here.

Initialize before usage¶

To interact with the FileSystem API, you need to initialize an instance first:

import com.google.modernstorage.storage.AndroidFileSystem

val fileSystem = AndroidFileSystem(context)

Get Path from Uri¶

Call toOkioPath to get a Path from a Uri:

val path = uri.toOkioPath()

Get Path from File¶

Call toOkioPath to get a Path from a File:

val path = File(context.filesDir, "myfile.jpg").toOkioPath()

Copy a file¶

You can easily copy a file to another location by using the copy method:

fileSystem.copy(originPath, targetPath)

Get file metadata¶

You can get the file size by using the method metadataOrNull:

import com.google.modernstorage.storage.MetadataExtras.DisplayName
import com.google.modernstorage.storage.MetadataExtras.MimeType

val fileMetadata = fileSystem.metadataOrNull(uri.toOkioPath())
Log.d("ModernStorage/uri", uri.toString())
Log.d("ModernStorage/isRegularFile", metadata.isRegularFile.toString())
Log.d("ModernStorage/isDirectory", metadata.isDirectory.toString())
Log.d("ModernStorage/size", metadata.size.toString())
Log.d("ModernStorage/lastModifiedAtMillis", metadata.lastModifiedAtMillis.toString())
Log.d("ModernStorage/displayName", metadata.extra(DisplayName::class).value)
Log.d("ModernStorage/mimeType", metadata.extra(MimeType::class).value)

Read a Text file Uri from the Storage Access Framework¶

/**
 * We register first an ActivityResult handler for Intent.ACTION_OPEN_DOCUMENT
 * Read more about ActivityResult here: https://developer.android.com/training/basics/intents/result
 */
val actionOpenTextFile = registerForActivityResult(OpenDocument()) { uri ->
    if(uri != null) {
        // textPath is an instance of okio.Path
        val textPath = uri.toOkioPath()
        Log.d("ModernStorage/metadata", fileSystem.metadataOrNull(textPath).toString())
        Log.d("ModernStorage/content", fileSystem.source(textPath).buffer().readUtf8())
    }
}

// Open file picker
actionOpenTextFile.launch(arrayOf("text/*"))