Custom response headers in Spring Boot - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a custom response header in Spring Boot?

A custom response header is an additional piece of information added to the HTTP response by the server. In Spring Boot, you can add these headers to provide extra data to the client beyond the standard headers.

beginner

How do you add a custom response header using Spring Boot's ResponseEntity?

You can add custom headers by creating an HttpHeaders object, adding your headers to it, and then passing it to ResponseEntity. For example: <br>HttpHeaders headers = new HttpHeaders();<br>headers.add("X-Custom-Header", "value");<br>return new ResponseEntity<>(body, headers, HttpStatus.OK);

intermediate

What is the purpose of the @ResponseHeader annotation in Spring Boot?

Spring Boot does not have a @ResponseHeader annotation. Instead, you add custom headers using HttpServletResponse, ResponseEntity, or WebFilter. This is important to know to avoid confusion.

beginner

How can you add a custom header using HttpServletResponse in a Spring Boot controller?

You can inject HttpServletResponse into your controller method and call response.addHeader("X-Custom-Header", "value") before returning the response body.

beginner

Why might you want to add custom response headers in a web application?

Custom headers can provide extra information like security tokens, version info, or debugging data. They help clients understand or handle the response better without changing the response body.

Which class in Spring Boot is commonly used to add custom response headers?

A HttpServletRequest

B HttpHeaders

C RequestBody

D PathVariable

HttpHeaders is used to set custom headers in the response.

How do you add a custom header using HttpServletResponse?

A response.addHeader("X-Name", "value")

B response.setBody("X-Name", "value")

C response.getHeader("X-Name")

D response.removeHeader("X-Name")

The addHeader method adds a new header to the response.

What is the correct way to return a response with custom headers using ResponseEntity?

A new ResponseEntity<>(headers, body, status)

B new ResponseEntity<>(status, headers, body)

C new ResponseEntity<>(body, headers, status)

D new ResponseEntity<>(body, status, headers)

The constructor takes body, headers, then status in that order.

Which of these is NOT a reason to add custom response headers?

A To change the HTTP method

B To send extra info like tokens

C To provide version info

D To help with debugging

Custom headers do not change the HTTP method.

Can you add multiple custom headers in Spring Boot response?

A Only if you use @ResponseHeader

B No, only one header is allowed

C Only with XML configuration

D Yes, by adding multiple headers to HttpHeaders

You can add as many headers as needed using HttpHeaders.

Explain how to add a custom response header in a Spring Boot controller using ResponseEntity.

Think about how you build the response with headers included.

Describe why custom response headers are useful in web applications.

Consider what extra data headers can carry.