title: Replace specific string by another - String#replaceAll()
body: <p>I'm actually developping a parser and I'm stuck on a method.</p>
  
  <p>I need to clean specifics words in some sentences, meaning replacing those by a whitespace or a <code>null</code>character.
  For now, I came up with this code: </p>
  
  <pre><code>private void clean(String sentence)
  {
      try {
          FileInputStream fis = new FileInputStream(
                  ConfigHandler.getDefault(DictionaryType.CLEANING).getDictionaryFile());
          BufferedReader bis = new BufferedReader(new InputStreamReader(fis));
          String read;
          List&lt;String&gt; wordList = new ArrayList&lt;String&gt;();
  
          while ((read = bis.readLine()) != null) {
              wordList.add(read);
          }
      }
      catch (IOException e) {
          e.printStackTrace();
      }
  
      for (String s : wordList) {
          if (StringUtils.containsIgnoreCase(sentence, s)) { // this comes from Apache Lang
              sentence = sentence.replaceAll("(?i)" + s + "\\b", " ");
          }
      }
  
      cleanedList.add(sentence);
  
  } 
  </code></pre>
  
  <p>But when I look at the output, I got all of the occurences of the word to be replaced in my <code>sentence</code> replaced by a whitespace.</p>
  
  <p>Does anybody can help me out on replacing only the exact words to be replaced on my sentence?</p>
  
  <p>Thanks in advance !</p>