还是JAVA强制转型的有关问题！请教这条语句的作用是什么？将对象具体化么

import java.util.*;public class IteratorTest{   public static void main(String[] args){      Collection c = new HashSet();//      Collection c = new HashSet();      c.add(new Name("f1","l1"));      c.add(new Name("f2","l2"));            c.add(new Name("f3","l3"));      //System.out.println(c);      Iterator i = c.iterator();      if(i.hasNext()){         Name n = (Name)i.next(); // 谁能帮我解释下这个语句的作用         System.out.println(n.getFname() + " ");         }      for(Iterator l = c.iterator();l.hasNext();){         Name n = (Name)l.next(); // 谁能帮我解释下这个语句的作用         if(n.getLname() == "l2"){            l.remove();            }         }         System.out.println(c);         }         static class Name{      private String fname;      private String lname;            public Name(String fname,String lname){         this.fname = fname;         this.lname = lname;         }            public String getFname(){         return fname;         }            public String getLname(){         return lname;         }                        public String toString(){         return fname +" " + lname;         }               }            }