title: Dangling meta character
body: <p>I keep getting an error about dangling meta character when I use '+', '*', '(', and ')'.</p>
  
  <p>I've already tried escaping those characters in the regex but I still get the error. This is what I have:</p>
  
  <pre><code>"[-\\+\\*/%\\(\\)]"
  </code></pre>
  
  <p><strong>Update:</strong></p>
  
  <p>test:</p>
  
  <pre><code>String input = "+";
  
  String vals = new WNScanner(input).getNextToken();    //**********
  System.out.println("token: " + vals);
  System.out.println(vals.matches("[-+*/%()]"));
  </code></pre>
  
  <p>from another class:</p>
  
  <pre><code>    ...
  
      String expression = input;
      ...
  
  public String getNextToken() {
  
      String[] token = {""};
  
      if (expression.length() == 0)
          return "";
  
      token = expression.split("\\s");
      recentToken = token[0];
      expression = expression.replaceFirst(token[0], "");     //*************
      expression = expression.trim();
  
      return token[0];
  
  
  }
  </code></pre>
  
  <p><strong>*</strong> there are exceptions on these lines.</p>