Creating a Hard Link in java

Question

Currently I use \'ln\' command via Runtime.exec(). It works fine. The only problem is that in order to do this fork, we need twice the heap space o

Answer 1

The answer can be read in Oracle The Java™ Tutorials Links, Symbolic or Otherwise

Answer 2

You could use Windows instead of UNIX? ;) I believe JDK7 will be using a call similar to CreateProcess instead of fork where available.

A more practical solution would be to create a new child process soon after starting. If you are using a 10g heap, another small Java process probably wont be so bad. Get that process (via use of streams) to exec.

Answer 3

This is very easy with JNA:

public interface CLibrary extends Library {
    CLibrary INSTANCE = (CLibrary)
        Native.loadLibrary((Platform.isWindows() ? "msvcrt" : "c"),
                           CLibrary.class);
    int link(String fromFile, String toFile);
}

public static void main(String[] args) {
    CLibrary.INSTANCE.link(args[0], args[1]);
}

Compile and run!

Answer 4

It’s easy in Java 7 using createLink:

Files.createLink(Paths.get("newlink"), Paths.get("existing"));

Answer 5

you could try JNA in place of JNI (JNA has some clear advantages over JNI); yes, check the JSR 203