title: Compare two lists of string using java stream
body: <p>I have two lists A and B. both have millions of elements. I want to compare and get all elements those are in list A but not in list B. Below is inefficient way to get elements.</p>
  
  <pre><code>   if (!B.containsAll(A)) {
          for (Integer id : A) {
              if (!B.contains(id)) {
                  System.out.println(id);
              }
          }
      }
  </code></pre>
  
  <p>I looking for an efficient way with or without streams to get elements</p>
  
  <p>help is appreciated in this regards. </p>
  
  <p>Thanks</p>