Creation of linkedList in java directly if we know the elements

not directly but

List<String> ll = new LinkedList<String>(Arrays.asList("String1","String2",...));

is what you're looking for

Have a look at Guava. It provides various static utility functions (and much much more), such as

Lists.newArrayList("a", "b", "c")

and similar for other data structures

An alternative approach using double-braces is shown in this earlier StackOverflow page.