title: Difference between String.isEmpty() and String.equals("")
body: <p>I created a "Color Chooser" with three textboxes where the user defines rgb values.<br>
  To check if values entered are correct (only numbers between 0-255) I'm using the following:</p>
  
  <pre><code>public Color getColor() {
      if (tfRed.getText().equals("") || tfGreen.getText().equals("") || tfBlue.getText().equals("")) {
                  return new Color(0, 0, 0, 0);
      } else {
          if (tfRed.getText().matches("\\d+") &amp;&amp; tfGreen.getText().matches("\\d+") &amp;&amp; tfBlue.getText().matches("\\d+")) {
              // ...
          } else {
              return new Color(0, 0, 0, 0);
          }
      }
  }
  </code></pre>
  
  <p>What I'm asking: is it better to use <code>String.isEmpty()</code>? I never found a satisfying answer and I've always wondered if there is any difference.  </p>