java - Glassfish 3.1 上的 @WebServlet 映射错误

Question

启动时，我在 Glassfish 3.1 上遇到以下严重错误:

The servlet 'MyInheritingServlet' has implementation 'com.mycompany.MyInheritingServlet' in xml. It does not match with 'com.mycompany.MyBaseServlet' from annotation @WebServlet.

这是我的代码片段:

  @WebServlet(name = "MyInheritingServlet", urlPatterns = "/MyInheritingServlet")
    public class MyInheritingServlet extends MyBaseServlet {
// implementation & overrides here ....
}

    @WebServlet(name = "MyBaseServlet", urlPatterns = "/MyBaseServlet")
    public class MyBaseServlet extends HttpServlet {
// implementation & overrides here ....
}

任何人都可以解释为什么 Glassfish 会发出此错误吗？

谢谢!

Answer 1

问题在于您的 MyInheritingServlet 正在扩展 MyBaseServlet。

因为MyInheritingServlet继承了一切，所以它也继承了MyBaseServlet的@WebServlet注释。所以它看起来类似于:

  @WebServlet(name = "MyInheritingServlet", urlPatterns = "/MyInheritingServlet")
  @WebServlet(name = "MyBaseServlet", urlPatterns = "/MyBaseServlet")
  public class MyInheritingServlet extends MyBaseServlet {
  // implementation & overrides here ....
  }

这似乎混淆了 Glassfish 3.1 中的实现。但在 Glassfish 4.1 中它似乎可以正常工作，不会出现错误消息。

来自The Java EE 6 Tutorial - Chapter 10 Java Servlet Technology :

Classes annotated with @WebServlet must extend the javax.servlet.http.HttpServlet class.