title: Use try-with-resources or close this "BufferedReader" in a "finally" clause
body: <p>Been looking for a way to fix this issue. Read all the previous answers but none helped me out.
  Could it be any error with SonarQube?</p>
  
  <pre><code>public class Br {
  
      public String loader(String FilePath){
  
          BufferedReader br;
          String str = null;
          StringBuilder strb = new StringBuilder();
          try {
              br = new BufferedReader(new FileReader(FilePath));
              while ((str = br.readLine()) != null) {
                  strb.append(str).append("\n");
              }
          } catch (FileNotFoundException f){
              System.out.println(FilePath+" does not exist");
              return null;
          } catch (IOException e) {
              e.printStackTrace();
          }
          return strb.toString();
      }
  }
  </code></pre>