How to copy files out of the currently running jar

Question

I have a .jar that has two .dll files that it is dependent on. I would like to know if there is any way for me to copy these files from within the .jar to a users temp folde

Answer 1

Since your dlls are bundeled inside your jar file you could just try to acasses them as resources using ClassLoader#getResourceAsStream and write them as binary files any where you want on the hard drive.

Here is some sample code:

InputStream ddlStream = .class
    .getClassLoader().getResourceAsStream("some/pack/age/somelib.dll");

try (FileOutputStream fos = new FileOutputStream("somelib.dll");){
    byte[] buf = new byte[2048];
    int r;
    while(-1 != (r = ddlStream.read(buf))) {
        fos.write(buf, 0, r);
    }
}

The code above will extract the dll located in the package some.pack.age to the current working directory.