title: Updating data in Vaadin's grid
body: <p>Hello everyone my problem is that my grid doesn't update data.</p>
  
  <p>I've a Thread that get new values from a database but when I assign the new DataProvider from the collection that get new values, the grid doesn't change anything.</p>
  
  <p>For example, the Grid contains the orders from clients, every 30 seconds a Thread search if there are new orders available, then y get all the orders in an ArrayList and set the new ArrayList in the grid’s DataProvider but the Grid continues having the same values as before.</p>
  
  <p>How can I refresh data in the Grid without refresh all the web page?</p>
  
  <p>Sorry for my English</p>
  
  <p>Thank you.</p>