title: Inserting an item between two items in a list in Java
body: <p>I want to find out how to efficiently insert an element between two elements in a list in Java. For example:</p>
  
  <p>[0, 5, 5, 1]</p>
  
  <p>would become</p>
  
  <p>[0, 5, 4, 5, 1]</p>
  
  <p>where 4 has been inserted into the list.</p>
  
  <p>What is the recommended way to implement this (as opposed to copying every single element into a new list?)</p>