Spring Boot Whitelabel Error page (type=Not Found, status=404)

Question

Good afternoon! I\'m starting spring studies, I\'m following a tutorial the same way, but it returns an error:

Folder structure:

The strange th

Answer 1

As answered by Deepak, main class should be in a root package above other packages. But if you don't want to do this, you can use:

@SpringBootApplication(scanBasePackages = {"com.other.packages","com.other"})
public class SpringAppApplication {
.....
}

Answer 2

verify that you have the correct thymeleaf dependency within your pom.xml:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>      
</dependency>

Answer 3

Make sure that your main class is in a root package above other classes.

When you run a Spring Boot Application, (i.e. a class annotated with @SpringBootApplication), Spring will only scan the classes below your main class package.

So your declaration goes like this

package br.com.SpringApp.SpringApp; inside this main class i.e SpringAppApplication

package br.com.SpringApp.SpringApp.controller; name of your controllers i.e EventoController & indexControllers

package br.com.SpringApp.SpringApp.model; name of your models i.e Evento

After This clean your project and re-run spring boot application;

Answer 4

Solution: If you are using @Controller over the Controller class then it will be treated as a MVC controller class. But if you want a special controller used in RESTFul web services then you to use @Controller along with @ResponseBody annotation or you can directly use @RestController over the Controller class. It worked for me as I was getting the same error while creating SpringBoot project with RestFul webservices.

package br.com.SpringApp.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class EventoController {

    @RequestMapping("/cadastroEvento")
    @ResponseBody
    public String form() {      
        return "evento/formEvento"; 
    }

}

or:

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@RestController
public class EventoController {

    @RequestMapping("/cadastroEvento")
    public String form() {      
        return "evento/formEvento"; 
    }

}

Answer 5

As a beginner to the SpringBoot, this error can be happened to anyone at least one time, because for a few reasons.

1. The Application class (eg: SpringAppApplication.java) should be at the root level, as well as the controller classes can be placed under the same level or maybe in a subdirectory. This application class should be denoted using @SpringBootApplication or extends SpringBootApplication
2. You may miss @RestController annotation at top of the controller class.
3. Or can be missed the mapping annotation.( @PostMapping("/save") or @GetMapping("/id") etc.)
4. finally just check whether you are entering the correct request mapping address(URL) you may miss a slash or @RequestMapping("/customer")(if the annotation available in your controller class) or spellings error in the URL.