Tested in Solaris and Linux for bash,csh and ksh shells.

RandomAccessFile.writeBytes() writes and reads a file created under umask 777.
Set umask to 777 , so that any file created will have 000 permissions.

Read and write methods in java.io should check file permissions of a file before reading and writing (or) File.canRead(),File.canWrite() and File.canExecute() return true, for the situations like this one otherwise it seems to be odd writing to a file for which File.canWrite() returns false.


<CODE>
import java.io.*;
import static java.lang.System.out;

class Test8 {

  public static void main(String ... args) throws IOException {
    
    byte b[] = new byte[20];
    File f = new File ("raf");
    RandomAccessFile raf = new RandomAccessFile(f,"rw");
    
    out.println("can Read "+f.canRead());
    out.println("can Write "+f.canWrite());
    out.println("can Execute "+f.canExecute());
    
    out.println("Writing Hello ...");
    raf.writeBytes("Hello ");
    out.println("done.");
    
    out.println("Writing World ...");
    raf.writeBytes("World");
    out.println("done.");
    
    out.print("reading ...");
    raf.seek(0);
    raf.read(b);
    out.println(new String(b));
    raf.close();
    
  }
}
</CODE>
<Result>
bash-3.00$ uname -a
SunOS client24 5.10 Generic sun4u sparc SUNW,Ultra-60
bash-3.00$ umask -S
u=,g=,o=
bash-3.00$ java Test8
can Read false
can Write false
can Execute false
Writing Hello ...
done.
Writing World ...
done.
reading ...Hello World
bash-3.00$

</Result>