Android :: Read / Write Permission In Data Directory?

I m using Android 1.5 my data directory does'nt have the read/write permissions

System.out.println("DAta can write??--->"+Environment.getDataDirectory().canWrite());
System.out.println("DAta can read??--->"+Environment.getDataDirectory().canRead());

So please suggest me how to provide permission for the data directory.
What m trying to do is to create a file and add some content to it iin the Data storage of the emulator like as below

private void writeToSDCard() {
try {
File lroot = Environment.getDataDirectory();
if (lroot.canWrite()){
File lfile = new File(lroot, "samplefile.txt");
FileWriter lfilewriter = new FileWriter(lfile);
BufferedWriter lout = new BufferedWriter(lfilewriter);
lout.write("XXXXXXXXXXXXXXXXXX");
lout.close();
}
} catch (IOException e) {
Log.e(m_cTAG, "Could not write file " + e.getMessage());
}
}