Resolving java.io.FileNotFoundException in Android 11 When Creating CSV Files

Learn how to fix the `EPERM (Operation not permitted)` error in Android 11 when attempting to create a CSV file, by understanding file name restrictions and adapting your code accordingly.
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This video is based on the question https://stackoverflow.com/q/66557956/ asked by the user 'Chadson' ( https://stackoverflow.com/u/14626392/ ) and on the answer https://stackoverflow.com/a/66560824/ provided by the user 'blackapps' ( https://stackoverflow.com/u/12121419/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Troubleshooting CSV File Creation in Android 11

If you’re a developer who has recently transitioned to using Android 11 in your applications, you might be facing some challenges—especially if you’re trying to create CSV files. Many users have reported receiving the error message: java.io.FileNotFoundException: EPERM (Operation not permitted). This can be frustrating, particularly if your code was functioning without issues in Android 10. In this post, we will explore the underlying reasons for this problem and present you with a clear solution.

Understanding the Problem

When attempting to write to a file, receiving permission-related errors often stems from changes in Android’s file handling and permission structure. Android 11 introduced several restrictions to enhance security, and one of them is stricter file name validation when creating files.

Why You’re Seeing the Error

File Naming Conventions: Android imposes restrictions on characters that are permissible in file names. Specifically, the character : is not allowed in the names of files.

Permissions: In addition to naming conventions, ensure you have the right permissions in your app manifest to write to external storage, which changed in Android 11.

A Step-by-Step Solution

Let’s delve into the solution by focusing on the most common issue: file name restrictions. The error you are encountering could be linked to the formatting of the date included in your CSV file's name.

Step 1: Modify Your Date Format

In your original code, you have the date formatted as dd-MM-yyyy HH:mm:ss. The presence of : in the time portion of the date violates the file naming conventions. To resolve this:

Change the date format to replace colons with an alternative character such as a period. This can be done by updating your date formatting method. Here’s a more suitable format:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Check Your Permissions

Ensure that your Android Manifest has the correct permissions defined for accessing external storage:

[[See Video to Reveal this Text or Code Snippet]]

Make sure android:requestLegacyExternalStorage is set to true in your application tag if applicable.

Step 3: Update the Code for File Creation

Now, revisit the section of your code that creates the CSV file. After making the date format change, it should look something like this:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

With these adjustments in your code, you should be able to resolve the java.io.FileNotFoundException: EPERM (Operation not permitted) error when creating CSV files on Android 11. Always remember to check for compliance with Android's file naming conventions and specific permissions for smoother development and fewer roadblocks. Happy coding!