How to rename a file to another file system?

Question

I got a strange problem on using renameTo(). I don't know why I can't rename to /mnt/desttest but it is ok to rename to /home/kit.ho/desttest. However, I already give every write permission to /mnt/. The return value is false while no specific reason. Who knows the reason?

import java.io.File;
public class renameFile {
    public static void main(String[] args) {
        File sourceFile = new File("/home/kit.ho/test");  
        File targetFile1 = new File("/mnt/desttest");  
        System.out.println("source file is exist? " + sourceFile.exists() + ", source file => " + sourceFile);  
        System.out.println(targetFile1 + " is exist? " + targetFile1.exists());  
        System.out.println("rename to " + targetFile1 + " => " + sourceFile.renameTo(targetFile1));  
        System.out.println("source file is exist? " + sourceFile.exists() + ", source file => " + sourceFile);   
    }
}

Edit: Finally, based on some answers, Rename function does not work on across file system, is there any workaround on this issue by not calling external command like "mv"?

Answer 1

You can't do a rename across file systems (partitions).