java - 为什么 Spring 不扫描我的 Controller

Question

我想了解一些有关 Spring 的知识。我正在尝试配置它，但有些东西我没有得到，因为 Spring 似乎无法识别我的 Controller 。

这是我的 web.xml

  <?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>dispatcher</display-name>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
    <servlet-name>dispatcher</servlet-name>
         <servlet-class>
            org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>/*</url-pattern>
  </servlet-mapping>
</web-app>

这是 servlet

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans     
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/mvc 
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context.xsd">

    <context:component-scan base-package="it.mexpenses.controller" />
    <mvc:annotation-driven />


    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <property name="suffix" value=".jsp"/>
        <property name="order" value="1" />
    </bean>
</beans>

Controller :

package it.mexpenses.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

@Controller
public class LoginController {

    @GetMapping("/login")
    public ModelAndView login() {
        User user = loginService.login(username, password);
        return new ModelAndView("welcome", "currentUser", null);
    }
}

Answer 1

在典型的 Spring MVC 应用程序中，您会发现有两个 Spring 配置文件，一个配置应用程序上下文的文件通常以 Spring 上下文监听器启动。

<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

Spring MVC 配置文件通常以 Spring 调度程序 servlet 开头。例如。

<servlet>
        <servlet-name>main</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>main</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

我强烈建议在 Spring 配置中使用注解。它使生活变得更加轻松并且更加现代......

您还可以使用 Spring Boot 生成项目，让您的生活更轻松:https://start.spring.io/

引用:Spring MVC: difference between <context:component-scan> and <annotation-driven /> tags?