Comments cannot be nested. : Comments « Java Source And Data Type « SCJP

If comments appear within a String or character literal, 
they are treated as part of the String or literal.

public class MainClass{
    public static void main(String[] argv){
       System.out.println("/* comments */");

1.2.1.Java provides three styles of comments
1.2.2.Comments cannot be nested.
1.2.3.Comments can appear at the beginning or end of any line in the source code file