Spring Boot MVC配置请求再次重定向到Dispatcher

Question

我正在努力解决这里描述的问题

找不到URI为Spring MVC的HTTP请求的映射

问题是，一旦资源解析器解析了视图，它就会再次重定向到Dispatcher，而Dispatcher找不到映射到它的a方法。

例如，如果用户请求/test，解析器将其映射到/views/test。jsp，dispatcher没有呈现响应，而是尝试查找路径/views/test。jsp。

我已经尝试将默认的dispatcher servlet路径更改为/（默认情况下是/）。

它不适用于Spring Boot配置。

我想知道是否有一种解决方案，无需将dispatcher path设置为除/以外的其他内容，比如/page。

以下是产生问题的测试代码。（这里是测试项目的github链接https://github.com/ConsciousObserver/stackoverflow/tree/master/TestMvc)

package com.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.embedded.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.DispatcherServlet;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@SpringBootApplication
public class TestMvcApplication {

    public static void main(String[] args) {
        SpringApplication.run(TestMvcApplication.class, args);
    }
}

@Configuration
class MvcConfig extends WebMvcConfigurerAdapter {
    public MvcConfig () {
        System.out.println("%%%%%%%%%%%%% " + getClass() + " loaded %%%%%%%%%%%%%%%");
    }

    @Bean
    public ServletRegistrationBean dispatcherRegistration(DispatcherServlet dispatcherServlet) {
        ServletRegistrationBean registration = new ServletRegistrationBean(
                dispatcherServlet);
        System.out.println("%%%%%%%%%%%%%%%%% Adding dispatcher servletmapping");
        registration.addUrlMappings("/");
        return registration;
    }
}

@Controller
class TestController {
    @RequestMapping("test")
    public String test() {
        return "test";
    }
}

应用属性

logging.level.org.springframework.web=DEBUG

spring.mvc.view.prefix: /views/
spring.mvc.view.suffix: .jsp

以下是相关日志

Returning [org.springframework.web.servlet.view.InternalResourceView: name 'test'; URL [/views/test.jsp]] based on requested media type 'text/html'
Rendering view [org.springframework.web.servlet.view.InternalResourceView: name 'test'; URL [/views/test.jsp]] in DispatcherServlet with name 'dispatcherServlet'
Forwarding to resource [/views/test.jsp] in InternalResourceView 'test'
DispatcherServlet with name 'dispatcherServlet' processing GET request for [/views/test.jsp]
Looking up handler method for path /views/test.jsp
Did not find handler method for [/views/test.jsp]
Matching patterns for request [/views/test.jsp] are [/**]
URI Template variables for request [/views/test.jsp] are {}
Mapping [/views/test.jsp] to HandlerExecutionChain with handler [ResourceHttpRequestHandler [locations=[ServletContext resource [/], class path resource [META-INF/resources/], class path resource [resources/], class path resource [static/], class path resource [public/]], resolvers=[org.springframework.web.servlet.resource.PathResourceResolver@21362712]]] and 1 interceptor
Last-Modified value for [/views/test.jsp] is: -1
Null ModelAndView returned to DispatcherServlet with name 'dispatcherServlet': assuming HandlerAdapter completed request handling
Successfully completed request
Successfully completed request

Answer 1

对于尝试其他解决方案却没有成功的人，您可能需要检查控制器类中是否存在ResponseBody注释。

@Controller
@EnableWebMvc
public class MainController {

    @Autowired
    BO bo = new BO();

    @RequestMapping(value = "/sayHello",
                    method = RequestMethod.GET, 
                    produces = "application/json")
    public @ResponseBody String sayHello() {
        return "Hellaa!!";
    }

}

Answer 2

我终于找到了解决办法。

包含以下依赖项可以解决这个问题。

<dependency>
    <groupId>org.apache.tomcat.embed</groupId>
    <artifactId>tomcat-embed-jasper</artifactId>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>jstl</artifactId>
</dependency>

我猜内部有一个JSP解析错误（或者JSTLView不存在），它将视图请求重定向到调度程序。

包含这些依赖项后，JSP视图将成功呈现。