Store Data in Cache directory Android (Kotlin)

As Android developers, one of the critical considerations in creating efficient and responsive applications is how to handle data storage. In this blog post, i’ll dive into the realm of data caching in Android and explore the benefits and best practices associated with utilizing the cache directory.

What is Cache directory ?

Android provides a dedicated cache directory for each app, designed to store temporary data that can be recreated when needed. This directory is an invaluable resource for optimizing performance and managing the storage footprint of your application.

Retrieving the Cache Directory

val cacheDir = context.cacheDir

Below line of code creates a File object representing the new text file in the cache directory.

val myFile = File(cacheDir, fileName)

Now you can save your file in cache directory with this File object like this :

object FileUtil {

        fun createAndWriteToCache(context: Context, fileName: String, data: String, isSuccess: (Boolean) -> (Unit)) {

            val cacheDir: File = context.cacheDir
            val myFile = File(cacheDir, fileName)

            try {
                BufferedOutputStream(FileOutputStream(myFile)).use { bos ->
                    bos.write(data.toByteArray())
                    isSuccess(true)
                }
            } catch (e: IOException) {
                e.printStackTrace()
                isSuccess(false)
            }
        }
    }

It’s always Good practice to put this code in your utils package you might need to use this frequently in your project.

Here in that code :

This line initializes a buffered output stream for efficient writing.

BufferedOutputStream(FileOutputStream(myFile))

This line Writes the data to the file in the form of bytes.

bos.write(data.toByteArray())

In that function i have passed a callback function which will give result whether data saved in cache directory or not as a boolean value, based on that we can do further process, you have to call function like this :

FileUtil.createAndWriteToCache(this, "mt_file.txt", binding.etData.text.toString()) { success ->
       if(success) {
          Toast.makeText(this, "File Saved Successfully!!", Toast.LENGTH_SHORT).show()
       } else {
          Toast.makeText(this, "Failed to Save file!!", Toast.LENGTH_SHORT).show()
       }
}

How to view cache directory ?

In android studio in right panel click on Device Manager, which will open explorer of Current runnig device’s,

Go to data folder, in that find your project’s package folder, if your package name is not visible then again go to data folder and then find project’s package folder.

In that folder you can is your cache directory, in that your file should be there with whatever name you gave in fileName like this:

You can save text, images, pdf etc any file in cache directory as temporary storage.

Remember this folder will be cleared when user Delete Application or clear all data from Settings.

Benefits of Caching in Android

1. Improved Performance: Accessing data from the cache is faster compared to fetching it from other sources, contributing to a more responsive user experience.
2. Reduced Network Usage: Caching allows you to minimize network requests by storing frequently accessed data locally, reducing the need for constant data retrieval.
3. Optimized Storage: The cache directory is automatically managed by the system, ensuring that it only contains temporary data. This aids in optimizing the overall storage usage of your application.

Best Practices for Data Caching

1. Use for Temporary Data: The cache directory is ideal for storing data that can be recreated when needed. Avoid storing critical or irreplaceable information in the cache.
2. Regular Cache Maintenance: Periodically review and clear unnecessary cached data to prevent storage bloat. Implement a cache management strategy to ensure optimal performance.
3. Security Considerations: Be cautious about the type of data you cache, especially if it involves sensitive user information. Ensure that security measures are in place to protect cached data.

Conclusion

Data caching in Android is a powerful tool for optimizing performance and managing storage efficiently. By leveraging the cache directory, developers can enhance the responsiveness of their applications while minimizing the impact on network resources. Incorporating best practices ensures a robust caching strategy that contributes to a seamless user experience.

Happy coding Android Devs!