code: public void doTag()
              throws JspException
      {
          // report any errors...
          if (hasErrors()) {
              reportErrors();
              return;
          }
  
          // calculate the output value...
          String text;
          if (_value != null) {
              text = _value.toString();
          }
          else {
              if (_defaultValue != null) {
                  text = _defaultValue;
              }
              else {
                  logger.warn(Bundle.getString("Tags_ContentExpressionNull", _value));
                  text = DEFAULT_NULL_TEXT;
              }
          }
  
          write(text);
      }
docs: Render the content.
  @throws JspException if a JSP exception has occurred