How to keep the data on the form when submitted and invalid in spring boot

Question

I have a form to handle password change.

<form method="POST" th:object="${changePassword}" th:action="@{/user/change_pass}">
    <input type="password" class="form-control" id="oldpass" th:field="*{oldPassword}">
    <input type="password" class="form-control" id="newpass" th:field="*{newPassword}"
    <input type="password" class="form-control" id="confirmPass" th:field="* {confirmNewPassword}"
    <input type="submit" class="btn btn-outline-primary btn-rounded waves-effect" value="Send"/>
</form>

In the controller

@GetMapping(value = "/user/change_pass")
private String changePasswordPage(Model model){

    if (!model.containsAttribute("changePassword")) {
        model.addAttribute("changePassword", new ChangePassword());
    }

    return "web/view/accPasswordPage";
}

@PostMapping(value = "/user/change_pass")
private String saveNewPassword(@Valid ChangePassword changePassword, BindingResult result, Model model, RedirectAttributes redirectAttributes){
    if (result.hasErrors()) {
        redirectAttributes.addFlashAttribute("org.springframework.validation.BindingResult.changePassword", result);
        redirectAttributes.addFlashAttribute("changePassword", changePassword);
        return "redirect:/user/change_pass";
    }
    return "redirect:/user/home";
}

when the user clicks send if the error and returns but the form data is lost as shown:

Is there any way for user data to be entered without being lost but still preserved? Thank you

Answer 1

I changed the View to following code and it worked.

<form method="POST" th:object="${changePassword}" th:action="@{/user/change_pass}">
    <input type="password" class="form-control" id="oldPassword" name="oldPassword" th:value="*{oldPassword}">
    <input type="password" class="form-control" id="newPassword" name="newPassword" th:value="*{newPassword}" />
    <input type="password" class="form-control" id="confirmNewPassword" name="confirmNewPassword" th:value="*{confirmNewPassword}" />
    <input type="submit" class="btn btn-outline-primary btn-rounded waves-effect" value="Send"/>
</form>

my controller code for skipping all other logic and do a simple redirect.

@GetMapping(value = "/user/change_pass")
    private String changePasswordPage(Model model){

        if (!model.containsAttribute("changePassword")) {
            model.addAttribute("changePassword", new ChangePassword());
        }

        return "index";
    }

    @PostMapping(value = "/user/change_pass")
    private String saveNewPassword(@Valid ChangePassword changePassword, BindingResult result, Model model, RedirectAttributes redirectAttributes){
            redirectAttributes.addFlashAttribute("org.springframework.validation.BindingResult.changePassword", result);
            redirectAttributes.addFlashAttribute("changePassword", changePassword);
            return "redirect:/user/change_pass";

    }