Spring MVC 3.0配置异常求助：手动输入URL才可运行，点击返回报404错误

Hey there! As someone who’s stumbled through Spring MVC’s early setup hurdles too, let’s break down why you’re hitting that 404 when trying to use /hello.do instead of directly accessing hello.jsp. Here’s what’s likely going wrong and how to fix it:

Common Issues & Solutions #

1. Your DispatcherServlet Isn’t Mapping to .do Requests #

The DispatcherServlet is Spring MVC’s "front controller"—it needs explicit instructions to handle requests ending with .do. Check your web.xml file to confirm the mapping is set correctly:

<servlet>
    <servlet-name>springmvc</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>springmvc</servlet-name>
    <!-- Tells the servlet to handle all .do requests -->
    <url-pattern>*.do</url-pattern>
</servlet-mapping>

2. Your Controller Isn’t Properly Mapped to /hello.do #

Make sure your controller class is annotated with @Controller and has a @RequestMapping targeting /hello.do. For Spring 3.0’s annotation-based approach, your controller should look like this:

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class HelloController {

    @RequestMapping("/hello.do")
    public String showHelloPage(Model model) {
        // Pass data to your view
        model.addAttribute("greeting", "Hello from Spring MVC!");
        // Return the view name (your resolver will handle the file path)
        return "hello";
    }
}

3. Missing or Misconfigured View Resolver #

Spring needs a view resolver to locate your JSP files when the controller returns a view name. Add this to your springmvc-servlet.xml (the file named after your DispatcherServlet in web.xml):

<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <!-- Path to your JSP directory (adjust to match your project structure) -->
    <property name="prefix" value="/WEB-INF/views/"/>
    <!-- File extension for your view files -->
    <property name="suffix" value=".jsp"/>
</bean>

With this setup, returning "hello" from your controller will tell Spring to look for /WEB-INF/views/hello.jsp—move your JSP here (instead of the root) to enforce access through the controller.

4. Controller Classes Aren’t Being Scanned #

If you’re using annotations like @Controller, you need to tell Spring to scan your package for these classes. Add this to your springmvc-servlet.xml:

<!-- Replace with your actual controller package path -->
<context:component-scan base-package="com.yourproject.controller"/>

Quick Verification Checklist #

• Confirm hello.jsp lives at /WEB-INF/views/hello.jsp (matches your view resolver’s prefix/suffix)
• Check that your project’s deployment structure includes the WEB-INF folder correctly
• Test accessing http://localhost:8080/SpringMVC/hello.do directly in your browser—if it works, the "back" link issue was likely due to an incorrect URL in your JSP

内容的提问来源于stack exchange，提问作者ed u