Cannot refer to an instance field pageTitle while explicitly invoking a cons

当下面这样时在第7行会提示：Cannot refer to an instance field pageTitle while explicitly invoking a cons

 public class LoginPage extends PageBase{
 //    private WebDriver driver;
 //    private final static
     String pageTitle = "登录 - BugFree";

     public LoginPage( WebDriver driver){
         super(driver, pageTitle);  //显示调用父类的构造函数，而且必须是第一行调用
         URL="http://192.168.1.151:8080/bugfree/index.php/site/login";

     }

--解决方法：在第4行变明前加上“ static”就不会报错了。