java - Spring MVC 基于 Java 的配置 - 未检测到 servlet 调度程序

Question

我正在编写一个 Spring MVC Web 应用程序。我尝试使用基于 Java 的配置来配置 Spring，但是如果不添加额外的 XML 配置，Spring 无法检测到我的 Controller 。

我的前端 Controller 类如下所示:

package no.magnus.controller; 
public class FrontController extends 
   AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[] {MvcConfig.class};
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return null;
    }

    @Override
    protected String[] getServletMappings() {
        return new String[] {"/"};
    }
}

我的MVC配置类:

package no.magnus.config;
@Configuration
@EnableWebMvc
@ComponentScan(basePackages = {"no.magnus"})
public class MvcConfig implements WebMvcConfigurer {

    @Bean
    public InternalResourceViewResolver viewResolver() {
        InternalResourceViewResolver vr = new InternalResourceViewResolver();
        vr.setSuffix(".jsp");
        return vr;
    }
}

一个简单的家庭 Controller :

package no.magnus.controller;
@Controller
public class HomeController {

    @RequestMapping("/home")
    public ModelAndView index() {

        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("index");
        return modelAndView;
    }
}

正在尝试访问 url http://localhost:8080/home我收到 404 错误。如果我将基于 XML 的配置添加到 web.xml 以及 xml servlet 配置中，则会检测到 home Controller 并返回 index.jsp。

子集 web.xml:

<servlet>
  <servlet-name>dispatcher</servlet-name>
  <servlet-class>org.springframework.web.servlet.DispatcherServlet
  </servlet-class>
  <init-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/dispatcher-servlet.xml</param-value>
  </init-param>
 </servlet>
 <servlet-mapping>
  <servlet-name>dispatcher</servlet-name>
  <url-pattern>/</url-pattern>
 </servlet-mapping>

调度程序-servlet.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:ctx="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context-4.0.xsd">
    <ctx:annotation-config/>
    <ctx:component-scan base-package="no.magnus"/>

</beans>

http://localhost:8080/homeindex.jsp返回成功!

我的期望是 Spring MVC 应能够从 java 代码检测 Spring MVC 配置，从而使上述 XML 配置变得多余。请澄清我的理解是否有误。 '

谢谢!

编辑1:应用克里斯建议的代码更改。新问题出现。仅使用 java 配置仍然没有返回 index.jsp。

├───java
│   └───no
│       └───magnus
│           ├───config
│           │       MvcConfig.java
│           │
│           └───controller
│                   FrontController.java
│                   HomeController.java
│
└───webapp
    │   result.jsp
    │
    └───WEB-INF       
        │   web.xml
        │
        └───jsp
                index.jsp

Answer 1

http://localhost:8080/home不会调用您的 HomeController 的 index()-方法 (/home-Mapping) - 在您发布的网址中 home 是您的应用程序的名称并且您需要 "/" 到 index.jsp 的映射。

请将您的FrontController更改为:

package no.magnus.config; 
public class FrontController extends 
   AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    protected Class<?>[] getRootConfigClasses() {
        // from
        // return new Class[] {MvcConfig.class};
        // to
        return null;
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        // from
        // return null;
        // to
        return new Class[] {MvcConfig.class};
    }

    @Override
    protected String[] getServletMappings() {
        return new String[] {"/"};
    }
}

你的 MvcConfig 应该是这样的:

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ViewResolverRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.view.InternalResourceViewResolver;


@EnableWebMvc
@Configuration
// to also scan subpackages for components
@ComponentScan("no.magnus.**")
public class MvcConfig
        implements
            WebMvcConfigurer {
    @Override
    public void configureDefaultServletHandling(final DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
        WebMvcConfigurer.super.configureDefaultServletHandling(configurer);
    }

    @Override
    public void configureViewResolvers(final ViewResolverRegistry registry) {
        registry.viewResolver(this.jspViewResolver());
        WebMvcConfigurer.super.configureViewResolvers(registry);
    }

    @Bean
    public InternalResourceViewResolver jspViewResolver() {
        final InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
        viewResolver.setOrder(1);
        // jsp-location!!! - please change it to where your jsp's are located
        viewResolver.setPrefix("/WEB-INF/jsp/");
        viewResolver.setSuffix(".jsp");
        return viewResolver;
    }
}

你的HomeController应该看起来像这样:

package no.magnus.controller;
@Controller("HomeController")
public class HomeController {

    // for the very first start
    // RequestMapping can be replaced with GetMapping
    @GetMapping("/")
    public ModelAndView index() {

        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("index");
        return modelAndView;
    }
}