Android Java not deleting files even with Root Access

Question

I've been making an Android app that clears the Cache & Data of my application. Don't forget, my device is rooted. So why doesn't this piece of code work? It clearly has Root permissions and full paths. What's the problem behind this?

        try {


            Process p = Runtime.getRuntime().exec("su rm -r /data/user/0/com.rick.app");
            p.waitFor();
            p = Runtime.getRuntime().exec("su rm -r /data/user_de/0/com.rick.app");
            p.waitFor();
            p = Runtime.getRuntime().exec("su rm -r /storage/emulated/0/Android/data/com.rick.app");
            p.waitFor();
            p = Runtime.getRuntime().exec("su rm -r /data/data/com.rick.app");
            p.waitFor();
            p = Runtime.getRuntime().exec("su rm -r /data/app/com.rick.app");
            p.waitFor();
            p = Runtime.getRuntime().exec("su rm -r /storage/emulated/obb/com.rick.app");
            p.waitFor();
            p = Runtime.getRuntime().exec("su rm -r /storage/emulated/0/Android/data/com.rick.app/");
            p.waitFor();
            //p = Runtime.getRuntime().exec("reboot");
            //p.waitFor();

            //Runtime.getRuntime().exec("reboot");
        } catch (IOException | InterruptedException e) {
            e.printStackTrace();
        }

It might be expecting you to provide a password for the sudo (`su`) command. — acarlstein, Sep 14 '22 at 19:11
1. You don't need Root to clear your own apps data, it can be done programmatically also. 2. What is printed in the logcat since you do `e.printStackTrace();`? — Darshan, Sep 14 '22 at 19:11
I don't see any logs that happen when I click the button that should run this code. — Rick Wilting, Sep 14 '22 at 19:30

score 0 · Answer 1 · answered Sep 15 '22 at 12:16

The command is wrong you should use sudo instead of su
Android has a lot of limitations! by default you can't use root commands with sudo! to do it you shou *ROOT your phone
to delete and create files in android you should add specific permissions in manifest.xml file and get permission from user
to create, edit and remive files you should use filling methods you can find theme here

score 0 · Answer 2 · answered Sep 15 '22 at 12:44

Generally if the command will fail you wont notice it because you dont check exit code and dont redirect the process output. Consider this code using the ProcessBuilder

Process process = new ProcessBuilder().inheritIO().command("sudo rm ...").start();
process.waitFor();
int exitCode = process.exitValue();
if (exitCode != 0) {
    System.err.println("Delete failed with exit code " + exitCode);
}

This way we can figure out what exactly happens here. As other pointed out java has also apis to delete files via File#delete or using nio Here is a snipped to delete it recursivly

Files.walk(Paths.get("/data/data/"))
    .map(Path::toFile)
    .sorted(Comparator.reverseOrder())
    .forEach(File::delete);

In Kotlin you can even use File#deleteRecursively

I just wanted to mention that you can actually get the cache directory via context.cacheDir()

It gives out the error Access Denied, because it doesn't ask for root anywhere. — Rick Wilting, Sep 16 '22 at 21:33

Android Java not deleting files even with Root Access

2 Answers2