title: Annotation for uppercase and trim String
body: <p>I have this code which <code>str</code> must be upper case and trimmed. </p>
  
  <pre><code>class A {
     private String str;
  
     public String getStr() { return str};
  
     public void setStr(String str) {
        if(str == null || str.equals(""))
             this.str = str;
        else 
             this.str = str.toUpperCase().trim();
     }
  
  }
  </code></pre>
  
  <p>What I'm looking for is to make it annotation based. Which could be used either as 
  <code>@UpperCaseTrim private String str;</code> or <code>@UpperCaseTrim public void setStr(String str) {...};</code>. 
  How could this be implemented, maybe in a best way? What would the annotation processor be?</p>