Java: How to reverse a linked list

public class ListNode<T>
{
T data;
ListNode<T> next;
public ListNode(T data)
{
this.data = data;
}
}
public class ListNode<T>{ T data; ListNode<T> next; public ListNode(T data) { this.data = data; }}

public class LinkedList<T>

{

ListNode<T> head;

public void add(T data)

{

ListNode<T> node = new ListNode<T>(data);

if ( head == null )

{

head = node;

}

else

{

node.next = head;

head = node;

}

}

public void reverse()

{

ListNode<T> curr = head;

ListNode<T> nxt = null;

ListNode<T> last = null;

while ( curr != null )

{

nxt = curr.next;

curr.next = last;

last = curr;

curr = nxt;

}

head = last;

}

public String toString()

{

StringBuilder strbld = new StringBuilder();

ListNode<T> curr = head;

while( curr != null )

{

strbld.append(curr.data.toString() + " ");

curr = curr.next;

}

return strbld.toString();

}

}

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