title: How to replace characters in a fixed length string?
body: <p>I'd like to replace the content of a string between specific positions with a fixed characters.</p>
  
  <p>Is there any common library (apache, guava) that provides a class similar to the following pseudocode?</p>
  
  <p><code>string.replaceBetween(10, 20, "*");</code></p>
  
  <p>If not, how could I best achieve this with regards to performance?</p>