Does Files.copy(Path,Path) create directories?

This is very easy with Files.createDirectories()

Path source = Path.of("c:/dir/dir-x/file.ext");
Path target = Path.of("c:/target-dir/dir-y/target-file.ext");
Files.createDirectories(target.getParent());
Files.copy(path, target, StandardCopyOption.REPLACE_EXISTING);    

And do not worry if the directories already exist, in that case it will do nothing and keep going...

Method Files.copy(C:/Users/java/dir1/ss1.txt,C:/Users/java/dir2) will not create directory, it will create file dir2 in directory java that will contain ss1.txt data.

You could try it with this code:

File sourceFile = new File( "C:/Users/java/dir1/ss1.txt" );
Path sourcePath = sourceFile.toPath();

File destFile = new File( "C:/Users/java/dir2" );
Path destPath = destFile.toPath();

Files.copy( sourcePath, destPath );

Remember use java.nio.file.Files and java.nio.file.Path.

If you want to use class form java.nio to copy files from one directory to other you should use Files.walkFileTree(...) method. You can see solution here Java: Using nio Files.copy to Move Directory.

Or you can simply use `FileUtils class from apache http://commons.apache.org/proper/commons-io/ library, available since version 1.2.

File source = new File("C:/Users/java/dir1");
File dest = new File("C:/Users/java/dir2");
try {
    FileUtils.copyDirectory(source, dest);
} catch (IOException e) {
    e.printStackTrace();
}