File Permission Denied

Question

Hello again! I have now come across the problem of being denied permission to open certain directories on my computer. If I am logged on as root that does not happen but when writing the program not everyone will be logged on as root. So, I guess what I am asking is how can I "catch" this error? Can I change permissions for this directory just to open and get the list and then change back. I would not be making any changes I am just trying to read the list of files/directories in there.
Any ideas?

Answer 1

Create a java.io.File object from the directory name and use the canRead() method to determine whether you can list the files.
  File directory = new File(..); // however you'd get this
  if (directory.isDirectory() && directory.canRead()) {
     File[] list = directory.listFiles();
     // do stuff
  // you can check to see if you can make new files in the
  // directory using canWrite
  if (directory.isDirectory() && directory.canWrite()) {
     // create a new file in the directory.
  }