How to acquire root access using shell script in Java code?

Question

I can get root access to phone using 'adb root' in my PC then change a file content under /data folder. Now I want to do it in a apk using Java code. I tried blow code:

Runtime.getRuntime().exec(new String[]{"sh", "/sdcard/my.sh"});

This function works well when shell command do not need a root permission. Now I change my.sh into

su root
chmod 777 /data/filetochange.xml
rm -r /data/filetochange.xml

But it didn't work. Can I do this in Java code?

Answer 1

I think your app need have root permission. You can try to add a line 'android:sharedUserId="android.uid.system"' to AndroidManifest.xml, which property can get system permission. But this is not enough, you need to do other steps and you can google it, there are many detailed tutorials online.