CODEWITHSUNDEEP
javaspring
wesleyy
wesleyy

Reputation: 2735

Spring controller gets invoked but returns 404

I am writing a Spring Boot application. I have written a simple controller that gets invoked whenever the endpoint is hit, but it still returns status 404 and not the specified return value.

HelloController

@Controller
public class MessageRequestController {

    @RequestMapping(method = RequestMethod.GET, value = "/hello", produces = "application/json")
    public String hello() {
        System.out.println("Hit me!");
        return "Hello, you!";
    }
}

Now whenever I call localhost:8080/hello, I see the console log "Hit me!", but "Hello, you!" is never returned. Postman outputs:

{
    "timestamp": 1516953147719,
    "status": 404,
    "error": "Not Found",
    "message": "No message available",
    "path": "/hello"
}

Application.java

@SpringBootApplication
@ComponentScan({"com.sergialmar.wschat"}) // this is the root package of everything
@EntityScan("com.sergialmar.wschat")
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

Upvotes: 38

Views: 28055

Answers (4)

Saravana
Saravana

Reputation: 12817

Change your method return a ResponseEntity<T>

@RequestMapping(method = RequestMethod.GET, value = "/hello", produces = "application/json")
public ResponseEntity<String> hello() {
    System.out.println("Hit me!");
    return new ResponseEntity<String>("Hello, you!", HttpStatus.OK);
}

or change the controller to RestController

@RestController
public class MessageRequestController {...}

CURL

ubuntu:~$ curl -X GET localhost:8080/hello
Hello, you!

Upvotes: 51

Ghasem Sadeghi
Ghasem Sadeghi

Reputation: 1854

When everything seems ok but receive 404, check this answer:

As you know:
 In the Spring MVC you can return view as a String or ModelAndView object.

IMPORTANT NOTE:
In both cases you have to pay attention to relative/absolute path:

  1. If you declare / in the beginning of the view name, you are using absolute path.
    Namely it does not matter class level @RequestMapping and directly introduce itself as the final view name.
  2. If you do not declare / in the beginning of the view name, you are using relative path (relative to the class path) and therefore it appends to the class level @RequestMapping to construct final view name.

So, you have to consider the above notes when use the Spring MVC.

Example:
1. create two HTML file test1.html and test2.html in the static folder of spring (boot) structure:
Please note that the class level @RequestMapping behaves as a folder path in the case of relative path.

--- resources
    --- static
        --- classLevelPath     //behaves as a folder when we use relative path scenario in view names   
            --- test2.html      //this will be used for relative path [case (2)]
        --- test1.html          //this will be used for absolute path [case (1)]
  1. create a controller class like as the below. This example shows different cases with return String and ModelAndView in both relative and absolute path.

@Controller
@RequestMapping("/classLevelPath")
public class TestController {

    //case(1)
    @RequestMapping("/methodLevelAbsolutePath1")
    public String absolutePath1(Model model){
        //model.addAttribute();
        //...
        return "/test1.html";  
    }

    //case(1)
    @RequestMapping("/methodLevelAbsolutePath2")
    public ModelAndView absolutePath2(Model model){
        ModelAndView modelAndView = new ModelAndView("/test1.html");
        //modelAndView.addObject()
        //....
        return modelAndView; 
    }

    //case(2)
    @RequestMapping("/methodLevelRelativePath1")
    public String relativePath1(Model model){
        //model.addAttribute();
        //...
        return "test2.html";
    }

    //case(2)
    @RequestMapping("/methodLevelRelativePath2")
    public ModelAndView relativePath2(Model model){
        ModelAndView modelAndView = new ModelAndView("test2.html");
        //modelAndView.addObject()
        //....
        return modelAndView;  
    }


}

Note:
You can specify the suffix of your view files by a ViewResolver (for example InternalResourceViewResolver or spring.mvc.view.suffix=.html in the appliction.properties file of Spring Boot and do not declare .html suffix in the above code.

Best Regard

Upvotes: 0

Marc Tarin
Marc Tarin

Reputation: 3169

Short version:

Annotate your endpoint method with ResponseBody to bind the return value to the response body.

@Controller
public class MessageRequestController {

    @RequestMapping(method = RequestMethod.GET, value = "/hello", produces = "application/json")
    @ResponseBody
    public String hello() {
        System.out.println("Hit me!");
        return "Hello, you!";
    }

}

You can instead annotate your class with RestController instead of Controller to apply ResponseBody to each method of the class.

@RestController
public class MessageRequestController {

    @RequestMapping(method = RequestMethod.GET, value = "/hello", produces = "application/json")
    public String hello() {
        System.out.println("Hit me!");
        return "Hello, you!";
    }

}

With @Controller, you use the default model-view from Spring Web MVC, and you're actually telling spring to render the view called Hello, you!.tml from your resources directory (src/main/resources/templates for a Spring Boot project, if I remember correctly).

You can read this article for more information about the Spring MVC REST Workflow.

Once you're more familiar with those concepts, you can even further customize your endpoint method using ResponseEntity.

Upvotes: 16

Saver
Saver

Reputation: 52

As you see the "hit me", there's no mapping issue, but in your @RequestMapping annotation you specifie a produce type to "application/json" and you return a simple poor String not formatted and without any header('Content-Type: application/json').

Add the header and format the outpout.

Upvotes: 2

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