为什么每个URL都“重定向”到欢迎文件URL？

Question

Servlets

@WebServlet("/")
public class AServlet extends HttpServlet {

-- loads an .jsp and displays "AServlet"

@WebServlet("/b")
public class BServlet extends HttpServlet {

-- returns an simple JSON

index.html

-- displays "Not a JSP"

web.xml

...
<welcome-file-list>
    <welcome-file>/</welcome-file>
</welcome-file-list>
...

Every url that doesn't match an servlet executes the same action as the A servlet.

Eg:

• ...localhost.../AppName/ -> displays AServlet - ok
• ...localhost.../AppName/ loremipsum -> displays AServlet - WHY DOESN'T IT RETURN A 404 NOT FOUND?
• ...localhost.../AppName/ b -> returns JSON - ok
• ...localhost.../AppName/ index.html -> even if the file exists, still displays "AServlet"

Answer 1

将Servlet映射到“ /”使其成为默认Servlet，这意味着它将处理所有与任何其他映射都不匹配的请求。