Incorrect Port Added to Redirect URL in Spring Boot App.

[anishgowda21]

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Environment

• GitHub Codespaces
• Spring Boot application
• Java

Description

When redirecting to an error page in my Spring Boot application running on GitHub Codespaces, an incorrect port (8080) is being added to the URL. This causes the redirection to fail.

Current Behavior

1. The application is accessible via https://[CODESPACE-NAME]-8080.app.github.dev/
2. When attempting to redirect to the error page, the resulting URL becomes https://[CODESPACE-NAME]-8080.app.github.dev:8080/error-page
3. This URL with the added :8080 doesn't work in the Codespaces environment.

Expected Behavior

The redirect should maintain the correct URL structure without adding the extra port:
https://[CODESPACE-NAME]-8080.app.github.dev/error-page

Code Snippet

@GetMapping("/cart")
public String getCart(HttpSession session, Model model, RedirectAttributes redirectAttributes) {
    // ... (other code)
    if (response.getStatusCode() != 200) {
        String baseUrl = UriComponentsBuilder.fromHttpUrl(request.getRequestURL().toString())
                            .replacePath(request.getContextPath())
                            .build()
                            .toUriString();
        System.out.println(baseUrl);
        redirectAttributes.addFlashAttribute("statusCode", response.getStatusCode());
        redirectAttributes.addFlashAttribute("message", response.getMessage());
        return "redirect:" + baseUrl + "/error-page";
    }
    // ... (rest of the method)
}

Attempted Solutions

1. Initially tried "redirect:/error-page", but it didn't work.
2. Implemented the UriComponentsBuilder solution as shown in the code snippet, but the issue persists.

Questions

1. How can I generate the correct redirect URL that works in the GitHub Codespaces environment?
2. Is there a way to detect if it's running in Codespaces and adjust the URL generation accordingly?
3. Are there any Spring Boot or Codespaces-specific configurations I might be missing?

Additional Context

The error page itself (/error-page) is defined as follows:

@GetMapping("/error-page")
public String errorPage(Model model) {
    String message = (String) model.asMap().getOrDefault("message", "Something bad happened");
    String statusCode = (String) model.asMap().getOrDefault("statusCode", "500");
    model.addAttribute("errorCode", statusCode);
    model.addAttribute("errorMessage", message);
    return "error-page";
}

Any help or guidance on resolving this redirection issue in the Codespaces environment would be greatly appreciated.