Modify file permissions in a windows environment

Question

Hi everyone,
I'm currently looking for a way to define a file as readable and writable under a Windows environment.
I saw 3 relevant methods in the java.io.File class, which are:
setReadable
setWritable
setExecutable
There are 2 versions of those methods, among which you have one that allow you t set readable and writable flags for "everyone" (meaning any user?).
I am currently develloping an application where files must be shared (readable and writable) between many users (from a Windows user point of view).
Reading the files causes no issue. However, a "FileNotFoundException (access denied)" is raised anytime I try to overwrite a file created by some other windows user.
Apparently, those setWritable, setReadable methods do not work ... or I am messing up somewhere?
The solution I'm looking for has to be Java native, since this application has to remain portable to any other platform (no Runtime.exec call with DOS commands).
Here's a dummy application I made which can help you reproduce my problem:
package local.test;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
public class Test {
     public static void main(String[] args) throws IOException{
          File file = new File("C:/test.txt");
          file.createNewFile();     
          System.out.println("R - " + file.setReadable(true));
          System.out.println("W - " + file.setWritable(true));
          System.out.println("X - " + file.setExecutable(true));
          System.out.println("R everyone - " + file.setReadable(true, false));
          System.out.println("W everyone - " + file.setWritable(true, false));
          System.out.println("X everyone - " + file.setExecutable(true, false));
          FileWriter writer = new FileWriter(file);
          writer.write(System.getProperty("user.name"));
          writer.close();
          System.out.println("R - " + file.setReadable(true));
          System.out.println("W - " + file.setWritable(true));
          System.out.println("X - " + file.setExecutable(true));
          System.out.println("R everyone - " + file.setReadable(true, false));
          System.out.println("W everyone - " + file.setWritable(true, false));
          System.out.println("X everyone - " + file.setExecutable(true, false));
}All functions return true with the first user. When executing with some other user, setWritable always return false.
The call to writer.write(System.getProperty("user.name")); raises an exception when trying to open the FileOutputStream.
Just for the memo, the files I want to create will be under the "Documents and Settings\All Users\Application Data" folder.
Thanks in advance for your help,
Eric

Answer 1

Alan,
Many thanks for your reply, it really helps knowing that I shouldn't look any further yet.
I believe it may be useful to add this note to the javadoc, because it currently mentions that the call to this method will set it as readable/writable/executable for "everyone", with no more information, which is why I was a bit lost.
Anyway, I'm looking forward to the JDK7 ;) Keep up the good work!