title: Take chars from array and place them randomly to create String
body: <p>I have got a char array (size 12) that can look like this:   </p>
  
  <pre><code>{'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l'}  
  </code></pre>
  
  <p>And I would like to create (in the most efficient way) a String that would be the result of taking the characters from the array and ordering them ~randomly (let's use that word), for example:  </p>
  
  <pre><code>“ahbejclfkdig”
  </code></pre>
  
  <p>I tried solutions with StringBuffer and random placing, but there was the problem of positions repeating. Also, I tried Collections.shuffle, but I don’t quite get this one working. I also looked at linear feedback shift register, but I don’t think is appropriate here. It is quite simple case, I will not be operating on large numbers, so memory allocation and speed should not raise any major issues.</p>