using java generics properly? -

im having problems java generics. when use next() iterator doesn't return object of same type instantiated with. recieve incompatible types error. can help?

i recieve xlint warning when compile linked list class.

public class linkedlist<type> {  private node<type> sentinel = new node<type>(); private node<type> current; private int modcount;  public linkedlist() {     // initialise instance variables     sentinel.setnext(sentinel);     sentinel.setprev(sentinel);     modcount = 0; } public void prepend(type newdata) {    node<type> newn = new node<type>(newdata);    node<type> temp;    temp = sentinel.getprev();    sentinel.setprev(newn);    temp.setnext(newn);    newn.setprev(temp);    newn.setnext(sentinel);               modcount++; }   private class listiterator implements iterator {     private int curpos, expectedcount;     private node<type> itnode;     private listiterator()     {         curpos =0;         expectedcount = modcount;         itnode = sentinel;     }      public boolean hasnext()     {         return (curpos < expectedcount);     }      public type next()     {         if (modcount != expectedcount)             throw new concurrentmodificationexception("cannot mutate in context of iterator");         if (!hasnext())             throw new nosuchelementexception("there no more elements");         itnode = itnode.getnext();         curpos++;         current = itnode;         return (itnode.getdata());     }  }  } 

here error occurs in main class after list created , filled different types of shapes.

shape test; iterator iter = unsorted.iterator(); test = iter.next(); 

iterator generic interface, listiterator neither generic nor parameterizes iterator. start making listiterator implement iterator<type>:

private class listiterator implements iterator<type> {     // rest should fine } 

or making listiterator generic (more complicated):

private class listiterator<t> implements iterator<t> {     private int curpos, expectedcount;     private node<t> itnode;     private listiterator()     {         curpos = 0;         expectedcount = modcount;         itnode = sentinel;     }      public boolean hasnext()     {         return (curpos < expectedcount);     }      public t next()     {         // snip     } }