Java Spring Web应用在Eclipse运行时出现404错误求助

Hey there, let's work through that 404 issue you're hitting. Since Tomcat confirms your app is deployed and there are no console errors, we can focus on a few key configuration and mapping checks:

• Verify DispatcherServlet Mapping in web.xml
  Double-check your <servlet-mapping> entry for the DispatcherServlet. The <url-pattern> determines which requests get routed to Spring. If your pattern is too restrictive (like *.do) but you're requesting a URL without that suffix, you'll get a 404. A common setup for catching all requests looks like this:

  <servlet>
      <servlet-name>springDispatcher</servlet-name>
      <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
      <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
      <servlet-name>springDispatcher</servlet-name>
      <url-pattern>/</url-pattern> <!-- Catches all requests except static resources -->
  </servlet-mapping>
  

• Check Controller Request Mapping Annotations
  Make sure your controller classes are annotated with @Controller (not just @Component), and that the @RequestMapping values on both the class and method match your request URL exactly. Spelling mistakes or mismatched paths are super common here. For example:

  @Controller
  @RequestMapping("/user") // Base path for all methods in this controller
  public class UserController {
      @RequestMapping("/profile") // Full path: /user/profile
      public String showProfile(Model model) {
          // Logic here
          return "profile"; // Maps to your view file (e.g., /WEB-INF/views/profile.jsp)
      }
  }
  

  If you're requesting http://localhost:8080/your-app/user/profile, this should work—don't forget the app's context path!

• Validate View Resolver Configuration
  Even if your request reaches the controller, a missing or misconfigured view resolver can cause a 404 when trying to render the response. For JSP views, ensure you have an InternalResourceViewResolver set up (either in XML or via Java config):
  XML example:

  <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
      <property name="prefix" value="/WEB-INF/views/"/> <!-- Path to your JSPs -->
      <property name="suffix" value=".jsp"/> <!-- File extension -->
  </bean>
  

  If your controller returns "profile", this resolver will look for /WEB-INF/views/profile.jsp—if that file doesn't exist, you'll get a 404.

• Confirm Your App's Context Path
  In Eclipse, when deploying to Tomcat, the app's context path isn't always the root (/). Go to your Tomcat server configuration → "Web Modules" tab, and check the "Path" value for your app. If it's /my-spring-app, your full request URL needs to include that, like http://localhost:8080/my-spring-app/user/profile.

• Check Tomcat Logs for Clues
  Sometimes console logs don't show the full picture, but Tomcat's local logs (found in [Tomcat install dir]/logs/) might have more details. Look at localhost.log for any view resolution errors, or localhost_access_log.* to confirm exactly which URL your browser is requesting—this can help spot typos you might have missed.

• Static Resource Handling (If Applicable)
  If you're trying to access CSS, JS, or images, make sure Spring isn't blocking those requests. For XML config, add:

  <mvc:resources mapping="/static/**" location="/WEB-INF/static/"/>
  

  For Java config, implement WebMvcConfigurer and override addResourceHandlers:

  @Override
  public void addResourceHandlers(ResourceHandlerRegistry registry) {
      registry.addResourceHandler("/static/**").addResourceLocations("/WEB-INF/static/");
  }
  

  This tells Spring to route static resource requests to the correct folder instead of trying to map them to a controller.

内容的提问来源于stack exchange，提问作者sagar