Iterative way of in order traversal

public void inOrderTraversal(TreeNode root){
Stack<TreeNode> stack=new Stack<TreeNode>();
pushLeft(root,s);

while(!s.isEmpty()){
TreeNode temp=stack.pop();
System.out.println(temp);
pushLeft(temp.right,s);
}
}

public void pushLeft(TreeNode node, Stack s){
while(node!=null){
s.push(node);
node=node.left;
}
}