Servlet 映射 Tomcat 错误 Eclipse

Question

I am trying to do servlet mapping in Eclipse. Working with annotations to map the servlets seems to be working fine, but when I try to use the web.xml file I am getting problems. I would like to be able to map jsp's as well, hence why I want to use the xml file over the annotation style. Here is the error I am encountering when trying to add a servlet mapping to the web.xml file.

'Starting Tomcat v8.0 Server at localhost' has encountered a problem. Server Tomcat v8.0 Server at localhost failed to start.

Here is my web.xml file:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
    id="WebApp_ID" version="3.1">
    <display-name>Ryans Testing Project</display-name>
    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>default.html</welcome-file>
        <welcome-file>default.htm</welcome-file>
        <welcome-file>default.jsp</welcome-file>
    </welcome-file-list>
    
    <servlet>
        <servlet-name>AController</servlet-name>
        <servlet-class>controller/AController</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>AController</servlet-name>
        <url-pattern>/AController</url-pattern>
    </servlet-mapping>


</web-app>

Also, here is an image of my file structure:

Answer 1

<servlet-class> tag can take only a fully qualified class name. So do it as

<servlet>
    <servlet-name>AController</servlet-name>
    <servlet-class>controller.AController</servlet-class>
</servlet>

where controller is a package name.

I would like to be able to map jsp's as well, hence why I want to use the xml file over the annotation style.

Here is what the Servlet 3.0 specification says:

10.13 Inclusion of a web.xml Deployment Descriptor

A web application is NOT required to contain a web.xml if it does NOT contain any Servlet, Filter, or Listener components or is using annota tions to declare the same. In other words an application containing only static files or JSP pages does not require a web.xml to be present.