Apps file permissions

[murali.lancer]

Hi all ,can any one help me in ,how to hide the files programatically in android ?is there any dirtect api ,like setHidden()?.

and how to set files readonly or writable ?
in both cases, like in sdcard files and the files which are in file system(" /data/data/packagename/ " folder).
and how to find programatically whether the sdcard inserted or not .(how to detect)

all these methods are available in j2me .

thanks in advance ,
murali dhuli