Spring Boot model.addAttribute - how to get message to display correctly?
Question
I found the following example to walk myself through a part of SpringBoot: found here
The example works without an error, but I am not able to wrap my head around why the addAttribute will not display the changed message, but rather returns only "message" as a string.
UPDATE The use of the @Controller annotation leads to an inability to execute for the project, and as a resolution, it needs to be @RestController . I'm not sure if that bears any significance for the general issue.
This is the controller code:
package com.example.MySecondSpringBootProject.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class HomeController {
@GetMapping("/")
public String hello(){
return "hello";
}
@GetMapping("/message")
public String message(Model model) {
model.addAttribute("message", "This is a custom message");
return "message";
}
}
This is the message html page:
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>Spring Demo Project</title>
</head>
<body>
<h1 th:text="${message}"></h1>
</body>
</html>
And this is the output from "/message" on the locahost:
I've looked at various implementations of addAttribute here and they all use an incoming value from a frontend to assign a value to said attribute, which makes sense for this endpoint, but in this case, the frontend is pulling the value passed into it from the second parameter of the method - at least it should.
I've tried this, to no effect:
@RequestMapping("/message")
public String message(Model model, @RequestParam(value="message") String message) {
model.addAttribute("message", "This is a custom message");
return "message";
}
Passing a second argument in the method, also to no effect, it just returns the "message" string:
@GetMapping("/message")
public String message(Model model, String str) {
model.addAttribute("message", "This is a custom message");
return "message";
}
I will keep looking into it, but my head is going into circles at this point, or I'm just not quite understanding something about the model.addAttribute concept.
Thank you in advance!
2 answers
solution1
1 ACCPTED 2022-11-14 04:30:45
try this solution:
@GetMapping("/message")
public String message(Model model) {
String msg = "This is a custom message" ;
model.addAttribute("msg", msg);
return "message";
}
for the view:
<h2 th:text="${msg}" align="center"></h2>
i hope this help you
solution2
1 2022-11-14 04:40:23
You are returning the string "message" try returning return model.addAtribute("message","this is custom message"); .
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.