title: StringBuilder append() and null values
body: <p>I have a list of <code>String</code>s, and I want to concatenate them with spaces in between. So I'm using <code>StringBuilder</code>. Now if any of the <code>String</code>s are <code>null</code>, they get stored in the <code>StringBuilder</code> literally as 'null'. Here is a small program to illustrate the issue:</p>
  
  <pre><code>public static void main(String ss[]) {
      StringBuilder sb = new StringBuilder();
  
      String s;
      s = null;
  
      System.out.println(sb.append("Value: ").append(s));
  }
  </code></pre>
  
  <p>I'd expect the output to be "Value: " but it comes out as "Value: null"</p>
  
  <p>Is there a way around this problem?</p>