How to return a html page from a restful controller in spring boot?

问题

I want to return a simple html page from controller, but I get only the name of the file not its content. Why?

This is my controller code:

@RestController
public class HomeController {

    @RequestMapping("/")
    public String welcome() {
        return "login";
    }
}

This is my project structure:

[

回答1:

When using @RestController like this:

@RestController
public class HomeController {

    @RequestMapping("/")
    public String welcome() {
        return "login";
    }
}

This is the same as you do like this in a normal controller:

@Controller
public class HomeController {

    @RequestMapping("/")
    @ResponseBody
    public String welcome() {
        return "login";
    }
}

Using @ResponseBody returns return "login"; as a String object. Any object you return will be attached as payload in the HTTP body as JSON.

This is why you are getting just login in the response.

回答2:

You can try using ModelAndView:

@RequestMapping("/")
public ModelAndView index () {
    ModelAndView modelAndView = new ModelAndView();
    modelAndView.setViewName("index");
    return modelAndView;
}

回答3:

Follow below steps

Must put the html files in resources/templates/
Replace the @RestController with @Controller
Remove if you are using any view resolvers.
Your controller method should return file name of view without extension like retunrn "index"

Include the below dependencies.

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

回答4:

The answer from Kukkuz did not work for me until I added in this dependency into the pom file:

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

From the guide here.

As well as updating the registry resources as outlined here.

It then started working just fine. If anyone in the future runs into the same issue and following the first answer does not solve your problem, follow these 2 other steps after utilizing the code in @Kukkuz's answer and see if that makes a difference.

回答5:

You should use login.html. And replace RestController with Controller

回答6:

Replace @RestController with @Controller.

回答7:

I'm not using Thymeleaf and the only way it worked for me was with @Controller in the class and

@RequestMapping(method = RequestMethod.GET, value = "/")
public String index() {
    return "index.html";
}

回答8:

Replace @Restcontroller with @controller. @Restcontroller returns only content not html and jsp pages.

回答9:

The String you return here:

 return "login";

Is actually the whole content what you send back to the browser.

If you want to have the content of a file to be sent back, one way is:

Open file
Read contents into String
Return the value

You can go by with this answer on the question Spring boot service to download a file

回答10:

The most correct and modern form is to use IoC to put dependencies into the endpoint method, like the thymeleaf Model instance...

 @Controller 
 public class GreetingController {
        @GetMapping("/greeting") 
        public String greeting(
            @RequestParam(name="name", required=false, defaultValue="World") String name, Model model) {
             model.addAttribute("name", name); 
             return "greeting"; 
             // returns the already proccessed model from src/main/resources/templates/greeting.html 
      }
 }

See complete example at: https://spring.io/guides/gs/serving-web-content/

回答11:

You get only the name because you return only the name return "login";. It's @RestController and this controller returns data rather than a view; because of this, you get only content that you return from method.

If you want to show view with this name you need to use Spring MVC, see this example.

回答12:

You can solve this in two ways:

First way: If you wish to keep using REST you have to you a ModelAndView object to render a HTML page. An example is being posted by Happy Nguyen and I am posting it once more here:

@RequestMapping("/")
public ModelAndView index () {
    ModelAndView modelAndView = new ModelAndView();
    modelAndView.setViewName("index");
    return modelAndView;
}

Second Way: If it is not important weather you keep using REST or not, so you can just change the @RestController to @Controller and make sure that you have already added Thymeleaf template engine.

回答13:

@Controller
public class WebController {
@GetMapping("/")

public String homePage() {
    return "index";
  }
}

来源：https://stackoverflow.com/questions/38700790/how-to-return-a-html-page-from-a-restful-controller-in-spring-boot

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java

html

Spring

spring-boot

controller