Spring Boot thymeleaf字段在页面之间传递表单输入

Question

I have an HTML form that allows a user to enter a username for a basic search function:

<form action="#" th:action="@{/admin}" th:object="${searchuser}" method="post">
  <p>Username: <input type="text" th:field="*{usern}"/></p>
  <p><input type="submit" value="Submit"/><input type="reset" value="Reset"/></p>
</form>

The results are then meant to be displayed on a different HTML page where I am calling the th:field created in the first HTML page:

<div class="formcontainer">
  <h1>Result</h1>
  <p th:text="${UserSearch.usern}"/>
  <a href="/admin">Submit another message</a>
</div>

The first HTML page loads fine, however when I press submit I get an error message of EL1007E: Property or field 'usern' cannot be found on null.

Here is my model:

public class Searchuser {

    private String usern;

    public String getUsern() {
        return usern;
    }

    public void setUsern(String usern) {
        this.usern = usern;
    }
}

And here is my controller:

@Controller
public class UserController {

    @GetMapping("/admin")
    public String greetingForm(Model model) {
        model.addAttribute("searchuser", new Searchuser());
        return "admin";
    }

    @PostMapping("/admin")
    public String greetingSubmit(@ModelAttribute Searchuser searchuser) {
        return "userresults";
    }
}

Answer 1

substitute

<p th:text="${UserSearch.usern}" />

with

<p th:text="${searchuser.usern}" />