title: Collect list of strings to map with Java 8 Stream API
body: <p>Could someone suggest how could I transform list like <code>["bla", "blabla", "blablabla"]</code> to map like <code>{"bla" : 3, "blabla" : 6, "blablabla" : 9}</code> with words stands for keys and values stands for words lengths?</p>
  
  <p>I do something like:</p>
  
  <pre><code>Map&lt;String, Integer&gt; map =  list.stream().collect(Collectors.groupingBy(Function.identity(), String::length));
  </code></pre>
  
  <p>but have no luck.</p>
  
  <p>Thank you!</p>