问题在于servlet-mapping的url模式。

the problem is in url pattern of servlet-mapping.

 <url-pattern>/DispatcherServlet</url-pattern>

假设我们的控制器是

@Controller
public class HomeController {
    @RequestMapping("/home")
    public String home(){
        return "home";
    }
}

当我们在浏览器上点击某个网址时。调度程序servlet将尝试映射此URL。

when we hit some URL on our browser. the dispatcher servlet will try to map this url.

我们的serlvet的url模式目前是 / Dispatcher ，这意味着资源来自 {contextpath} / Dispatcher

the url pattern of our serlvet currently is /Dispatcher which means resources are served from {contextpath}/Dispatcher

但是当我们请求 http：// localhost：8080 / home $ c时$ c>我们实际上要求 / 中的资源不可用。
所以要么我们需要说调度员servlet从 / 服务

but when we request http://localhost:8080/home we are actually asking resources from / which is not available. so either we need to say dispatcher servlet to serve from / by doing

<url-pattern>/</url-pattern>

我们通过 / Dispatcher / * 来自/ Dispatcher服务code>

例如

<?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>springsecuritydemo</display-name>

  <servlet>
    <description></description>
    <display-name>offers</display-name>
    <servlet-name>offers</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>offers</servlet-name>
    <url-pattern>/Dispatcher/*</url-pattern>
  </servlet-mapping>

</web-app>

并请求 http：// localhost：8080 / Dispatcher / home
或只需 / 就可以请求

http://localhost:8080/home