SimpleStorage

Additional

Language
Kotlin
Version
1.5.5 (Jun 27, 2023)
Created
Aug 17, 2020
Updated
Dec 18, 2023
Owner
Anggrayudi H (anggrayudi)
Contributors
Anggrayudi H (anggrayudi)
Harsh Shandilya (msfjarvis)
Dicken Christian (dknchris)
Stefan Oberdörfer (stefanoberdoerfer)
kuragehime (kuragehimekurara1)
Adhima Arisandi Budiono (adhimaab)
Rizky Alfikri (rizkyAlfikri)
Su-Bret
gee12
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SimpleStorage

Table of Contents

Overview

The more higher API level, the more Google restricted file access on Android storage. Although Storage Access Framework (SAF) is designed to secure user's storage from malicious apps, but this makes us even more difficult in accessing files. Let's take an example where java.io.File has been deprecated in Android 10.

Simple Storage ease you in accessing and managing files across API levels. If you want to know more about the background of this library, please read this article: Easy Storage Access Framework in Android with SimpleStorage

Adding Simple Storage into your project is pretty simple:

implementation "com.anggrayudi:storage:X.Y.Z"

Where X.Y.Z is the library version:

All versions can be found here. To use SNAPSHOT version, you need to add this URL to the root Gradle:

allprojects {
    repositories {
        google()
        mavenCentral()
        // add this line
        maven { url "https://oss.sonatype.org/content/repositories/snapshots" }
    }
}

Java Compatibility

Simple Storage is built in Kotlin. Follow this documentation to use it in your Java project.

Terminology

Other Terminology

Check Accessible Paths

To check whether you have access to particular paths, call DocumentFileCompat.getAccessibleAbsolutePaths(). The results will look like this in breakpoint:

All paths in those locations are accessible via functions DocumentFileCompat.from*(), otherwise your action will be denied by the system if you want to access paths other than those. Functions DocumentFileCompat.from*() (next section) will return null as well. On API 28-, you can obtain it by requesting the runtime permission. For API 29+, it is obtained automatically by calling SimpleStorageHelper#requestStorageAccess() or SimpleStorageHelper#openFolderPicker(). The granted paths are persisted by this library via ContentResolver#takePersistableUriPermission(), so you don't need to remember them in preferences:

buttonSelectFolder.setOnClickListener {
    storageHelper.openFolderPicker()
}

storageHelper.onFolderSelected = { requestCode, folder ->
    // tell user the selected path
}

In the future, if you want to write files into the granted path, use DocumentFileCompat.fromFullPath():

val grantedPaths = DocumentFileCompat.getAccessibleAbsolutePaths(this)
val path = grantedPaths.values.firstOrNull()?.firstOrNull() ?: return
val folder = DocumentFileCompat.fromFullPath(this, path, requiresWriteAccess = true)
val file = folder?.makeFile(this, "notes", "text/plain")

Read Files

In Simple Storage, DocumentFile is used to access files when your app has been granted full storage access, included URI permissions for read and write. Whereas MediaFile is used to access media files from MediaStore without URI permissions to the storage.

You can read file with helper functions in DocumentFileCompat and MediaStoreCompat:

DocumentFileCompat

  • DocumentFileCompat.fromFullPath()
  • DocumentFileCompat.fromSimplePath()
  • DocumentFileCompat.fromFile()
  • DocumentFileCompat.fromPublicFolder()

Example

val fileFromExternalStorage = DocumentFileCompat.fromSimplePath(context, basePath = "Download/MyMovie.mp4")

val fileFromSdCard = DocumentFileCompat.fromSimplePath(context, storageId = "9016-4EF8", basePath = "Download/MyMovie.mp4")

MediaStoreCompat

  • MediaStoreCompat.fromMediaId()
  • MediaStoreCompat.fromFileName()
  • MediaStoreCompat.fromRelativePath()
  • MediaStoreCompat.fromFileNameContains()
  • MediaStoreCompat.fromMimeType()
  • MediaStoreCompat.fromMediaType()

Example

val myVideo = MediaStoreCompat.fromFileName(context, MediaType.DOWNLOADS, "MyMovie.mp4")

val imageList = MediaStoreCompat.fromMediaType(context, MediaType.IMAGE)

Manage Files

DocumentFile

Since java.io.File has been deprecated in Android 10, thus you have to use DocumentFile for file management.

Simple Storage adds Kotlin extension functions to DocumentFile, so you can manage files like this:

  • DocumentFile.getStorageId()
  • DocumentFile.getStorageType()
  • DocumentFile.getBasePath()
  • DocumentFile.copyFileTo()
  • List<DocumentFile>.moveTo()
  • DocumentFile.search()
  • DocumentFile.deleteRecursively()
  • DocumentFile.getProperties()
  • DocumentFile.openOutputStream(), and many more…

MediaFile

For media files, you can have similar capabilities to DocumentFile, i.e.:

  • MediaFile.absolutePath
  • MediaFile.isPending
  • MediaFile.delete()
  • MediaFile.renameTo()
  • MediaFile.copyFileTo()
  • MediaFile.moveFileTo()
  • MediaFile.openInputStream()
  • MediaFile.openOutputStream(), etc.

Request Storage Access, Pick Folder & Files, Request Create File, etc.

Although user has granted read and write permissions during runtime, your app may still does not have full access to the storage, thus you cannot search, move and copy files. You can check whether you have the storage access via SimpleStorage.hasStorageAccess() or DocumentFileCompat.getAccessibleAbsolutePaths().

To enable full storage access, you need to open SAF and let user grant URI permissions for read and write access. This library provides you an helper class named SimpleStorageHelper to ease the request process:

class MainActivity : AppCompatActivity() {

    private val storageHelper = SimpleStorageHelper(this)

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Only setup required callbacks, based on your need:
        storageHelper.onStorageAccessGranted = { requestCode, root ->
            // do stuff
        }
        storageHelper.onFolderSelected = { requestCode, folder ->
            // do stuff
        }
        storageHelper.onFileSelected = { requestCode, files ->
            // do stuff
        }
        storageHelper.onFileCreated = { requestCode, file ->
            // do stuff
        }

        // Depends on your actions:
        btnRequestStorageAccess.setOnClickListener { storageHelper.requestStorageAccess() }
        btnOpenFolderPicker.setOnClickListener { storageHelper.openFolderPicker() }
        btnOpenFilePicker.setOnClickListener { storageHelper.openFilePicker() }
        btnCreateFile.setOnClickListener { storageHelper.createFile("text/plain", "Test create file") }
    }

    override fun onSaveInstanceState(outState: Bundle) {
        storageHelper.onSaveInstanceState(outState)
        super.onSaveInstanceState(outState)
    }

    override fun onRestoreInstanceState(savedInstanceState: Bundle) {
        super.onRestoreInstanceState(savedInstanceState)
        storageHelper.onRestoreInstanceState(savedInstanceState)
    }

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)
        // Mandatory for direct subclasses of android.app.Activity,
        // but not for subclasses of androidx.fragment.app.Fragment, androidx.activity.ComponentActivity, androidx.appcompat.app.AppCompatActivity
        storageHelper.storage.onActivityResult(requestCode, resultCode, data)
    }

    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        // Mandatory for direct subclasses of android.app.Activity,
        // but not for subclasses of androidx.fragment.app.Fragment, androidx.activity.ComponentActivity, androidx.appcompat.app.AppCompatActivity
        storageHelper.onRequestPermissionsResult(requestCode, permissions, grantResults)
    }
}

Simple, right?

This helper class contains default styles for managing storage access. If you want to use custom dialogs for SimpleStorageHelper, just copy the logic from this class.

Move & Copy: Files & Folders

Simple Storage helps you in copying/moving files & folders via:

  • DocumentFile.copyFileTo()
  • DocumentFile.moveFileTo()
  • DocumentFile.copyFolderTo()
  • DocumentFile.moveFolderTo()

For example, you can move a folder with few lines of code:

val folder: DocumentFile = ...
val targetFolder: DocumentFile = ...

// Since moveFolderTo() is annotated with @WorkerThread, you must execute it in the background thread
folder.moveFolderTo(applicationContext, targetFolder, skipEmptyFiles = false, callback = object : FolderCallback() {
    override fun onPrepare() {
        // Show notification or progress bar dialog with indeterminate state
    }

    override fun onCountingFiles() {
        // Inform user that the app is counting & calculating files
    }

    override fun onStart(folder: DocumentFile, totalFilesToCopy: Int, workerThread: Thread): Long {
        return 1000 // update progress every 1 second
    }

    override fun onParentConflict(destinationFolder: DocumentFile, action: FolderCallback.ParentFolderConflictAction, canMerge: Boolean) {
        handleParentFolderConflict(destinationFolder, action, canMerge)
    }

    override fun onContentConflict(
        destinationFolder: DocumentFile,
        conflictedFiles: MutableList<FolderCallback.FileConflict>,
        action: FolderCallback.FolderContentConflictAction
    ) {
        handleFolderContentConflict(action, conflictedFiles)
    }

    override fun onReport(report: Report) {
        Timber.d("onReport() -> ${report.progress.toInt()}% | Copied ${report.fileCount} files")
    }

    override fun onCompleted(result: Result) {
        Toast.makeText(baseContext, "Copied ${result.totalCopiedFiles} of ${result.totalFilesToCopy} files", Toast.LENGTH_SHORT).show()
    }

    override fun onFailed(errorCode: ErrorCode) {
        Toast.makeText(baseContext, "An error has occurred: $errorCode", Toast.LENGTH_SHORT).show()
    }
})

The coolest thing of this library is you can ask users to choose Merge, Replace, Create New, or Skip Duplicate folders & files whenever a conflict is found via onConflict(). Here're screenshots of the sample code when dealing with conflicts:

Read MainActivity from the sample code if you want to mimic above dialogs.

FAQ

Having trouble? Read the Frequently Asked Questions.

Other SimpleStorage Usage Examples

SimpleStorage is used in these open source projects. Check how these repositories use it:

License

Copyright © 2020-2023 Anggrayudi Hardiannico A.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.