[Spring MVC] What is my Spring MVC controller not working?

以下是上udemy課程裡給出的方法，親測，有效：

THIS IS AN ECLIPSE CACHING BUG

IF YOUR CONTROLLER DOESN'T WORK THEN TRY THE STEPS BELOW

BE SURE TO COME BACK TO THIS ARTICLE

Debug Tip #0: Make sure you are accessing the correct URL

You need to access the correct URL, localhost:8080/spring-mvc-demo/

Note: Do not attempt to run the JSP files directly. This will not work due to MVC.

Debug Tip #1: Make Sure your Package Names is consistent

The Spring configuration file used in the videos expects for your controller to be in the package:

package com.luv2code.springdemo.mvc;

Make sure your controller is this package.

Debug Tip #2: Clear Cache

This is normally a caching issue with Eclipse.

Here are some steps to clear the Eclipse cache and Tomcat cache.

1. In the Server's tab in Eclipse, Stop the Tomcat server

2. Right-click the server and select "Clean..."

3. Right-click the server again and select "Clean Tomcat Work Directory..."

---

4. In the Eclipse, select the top-level menu option, Project > Clean ...

5. Be sure your project is selected and click Ok

6. Restart Eclipse

Retest your application. If you continue to have problems try Debug Tip #2

Debug Tip #3: Import the Project in  a new workspace

1. Copy your project to a new directory on your computer like, c:\foobar

2. In Eclipse, open a new workspace: Create a new workspace in Eclipse: File > Switch Workspace > Other ... > give any name

3. In Eclipse, import the project 

3a. Use File > Import > General > Existing Projects into Workspace

3b. Browse to directory: c:\foobar

4. In your new workspace, add a reference to the Tomcat server

5. Test your app in the new workspace