@ResponseStatus documentation incorrect

[Tibotanum]

I think the documentation of @ResponseStatus in spring-web 6.0.7 is not correct. It says:

"The status code is applied to the HTTP response when the handlermethod is invoked and overrides status information set by other means,like ResponseEntity or "redirect:"."

However, when the following method is called in a @Controller class it does not return the HttpStatus.I_AM_A_TEAPOT status (418) but the HttpStatus.INTERNAL_SERVER_ERROR (500):

@RequestMapping("/hello")
@ResponseStatus(HttpStatus.I_AM_A_TEAPOT)
ResponseEntity<List<String>> doHello() {
    return ResponseEntity.internalServerError().body(Arrays.asList("hello", "goodbye"));
}

So, effectively the status set on the ResponseEntity is returned which is the opposite of what the documentation says.

When debugging, at some point the following method is called:

org.springframework.web.servlet.mvc.method.annotation.HttpEntityMethodProcessor.handleReturnValue(Object, MethodParameter, ModelAndViewContainer, NativeWebRequest)

Here, the ServletServerHttpResponse outputMessage initially contains the code 418 but later this is overwritten by the status of the ResponseEntity. It appears a ResponseEntity is also created within the method if the return value of the controller method is a ProblemDetail or ErrorResponse which could mean that a status on these types also overwrites the status defined by the @ResponseStatus.

The following controller method returns the expected status code 418:

@RequestMapping("/responseStatus")
@ResponseStatus(HttpStatus.I_AM_A_TEAPOT)
@ResponseBody
String doResponseStatus() {
    return "hello";
}

My POM.xml looks as follows:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>3.0.5</version>
		<relativePath /> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.example</groupId>
	<artifactId>demo</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>demo</name>
	<description>Demo project for Spring Boot</description>
	<properties>
		<java.version>17</java.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>
	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>
</project>

My main class:

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemoApplication {

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

}

And my controller class:

package com.example.demo;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;

import org.springframework.http.HttpStatus;
import org.springframework.http.ProblemDetail;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.ErrorResponse;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.context.request.WebRequest;

import jakarta.servlet.http.HttpServletRequest;

@Controller
public class HelloController {

	@RequestMapping("/hello")
	@ResponseStatus(HttpStatus.I_AM_A_TEAPOT)
	ResponseEntity<List<String>> doHello() {
		return ResponseEntity.internalServerError().body(Arrays.asList("hello", "goodbye"));
	}
	
	@RequestMapping("/responseStatus")
	@ResponseStatus(HttpStatus.I_AM_A_TEAPOT)
	@ResponseBody
	String doResponseStatus() {
		return "hello";
	}

}

[rstoyanchev]

That seems to have been updated in 55db4ae for #18019, which was intended to clarify the use of @ResponseStatus with HTML redirect views. However, even in that case it doesn't seem to override an explicit status in RedirectView.

I need to have a closer look to double check this, but documentation certainly needs an update, and indeed the annotation is not expected to override the same from ResponseEntity.