renameTo()

[Vinney Shanmugam]

renameTo() API in file will be true if and only if the renaming is success. Else it will be false. So, When it fails, is there a way to check why it failed, say like some error codes as Permission denied, file not exists() sort of things. I have a application which does not renames the files if it is in the ROOT(/) direcotry. The platform ix UNIX.

[Vijitha Kumara]

Check for the SecurityException thrown if the security manager exists and does not allow the write access.

[Vinney Shanmugam]

SecurityException was not thrwon too. Please find below the code given,

import java.io.File;

public class FileMover {

        public static void main(String[] args) {
                        moveIO(args);
        }

        public static void moveIO(String[] args) {
            File file = new File(args[0]);
            if(!file.exists())
                System.out.println(file + " is not present");
            File dir = new File(args[1]);
            if(!dir.exists())
                System.out.println(dir + " is not present");

            try {
            boolean success = file.renameTo(new File(dir, file.getName()));

            System.out.println("Has file been moved successfully ? \n" + success );
            }
            catch(SecurityException se) {
            se.printStackTrace();
            }
        }

}

[Vijitha Kumara]

If file/dir does not exist why you continue the method? Then you will get false anyway if the file doesn't exists.

[Vinney Shanmugam]

Ahhh! Thanks for pointing to it. But, I am worried when the file exists???

[Rob Spoor]

The folder should exist, there just shouldn't be a file with the name in it. So change it like this:

File dir = new File(args[1]);   
if (!dir.exists())
{
    System.out.println(dir + " is not present");   
    // it doesn't exist, so just create the folder
    boolean success = dir.mkdirs();
    System.out.println("Has dir been created successfully ? \n" + success );
}
if (!dir.isDirectory())
{
    System.out.println(dir + " is not a directory; it is a file or it does not exist");
    // dir already existed but not as a directory, or mkdirs() returned false
    // keep in mind, the renaming will fail if this is true
}
File destination = new File(dir, file.getName());
if (destination.exists())
{
    System.out.println(destination + " is already present");   
    // renaming will fail
}
try
{   
    boolean success = file.renameTo(destination); 
    System.out.println("Has file been moved successfully ? \n" + success );   
}   
catch(SecurityException se)
{   
    se.printStackTrace();   
}