Скачать или смотреть Allowing CORS Policy on Fetch in Vue.js to Connect with Spring Backend

Discover how to solve CORS policy issues in Vue.js when making requests to a Spring backend. Step-by-step guide to properly configure CORS to ensure smooth communication between your front-end and back-end applications.
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How to Allow CORS Policy on Fetch in Vue.js to Backend

When developing web applications, you might encounter Cross-Origin Resource Sharing (CORS) issues. This is particularly common when your frontend (such as a Vue.js application) is hosted on a different server or port than your backend (such as a Spring application). In this guide, we'll delve into how to resolve a specific CORS issue that arises when making fetch requests from Vue.js to your Spring backend.

Understanding the CORS Problem

CORS is a security feature implemented by web browsers to prevent malicious sites from making requests to a different domain than the one that served the web page. In your case, you're trying to make a request from http://localhost:8081 (Vue.js frontend) to http://localhost:8080 (Spring backend). You received an error stating:

[[See Video to Reveal this Text or Code Snippet]]

This message indicates that your backend needs to be configured to allow requests from your frontend's origin.

Solution to the CORS Issue

To resolve this CORS issue, you need to ensure that your Spring backend is properly configured to allow requests from your Vue.js application. Follow these steps:

Step 1: Modify your Spring Controller

You need to make a couple of adjustments in your Spring backend code. Here’s what to do:

Add @ RequestMapping("/") Above the Controller Annotation: This makes it clear to Spring that all mappings for this controller are relative to the root.

Remove headers from the method annotations: Including headers in your method annotations can sometimes confuse Spring, leading to the CORS issues you're encountering.

Here’s how your modified controller should look:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Test Your Application

After making these changes, restart your Spring application and test the fetch request from your Vue.js frontend again. The CORS policy errors should be resolved, allowing your frontend to communicate seamlessly with the backend.

Troubleshooting Common Issues

If you still encounter CORS errors, here are a few troubleshooting tips:

Clear Browser Cache: Sometimes changes do not take effect due to cached policies. Clearing your cache can help.

Check Console for Errors: Open your browser's developer console and check for any additional errors that might indicate configuration issues.

Review Networking Settings: Make sure there are no network firewalls or restrictions that could be interfering with the request.

Conclusion

CORS policies are essential in protecting your application but can be a hurdle during development. By following the steps outlined above, you can ensure that your Vue.js frontend can communicate with your Spring backend without any hitches. With the correct configurations in place, you'll pave the way for a smoother development experience and a robust application.

Feel free to share your experiences or any further questions about resolving CORS issues in your projects!