ResponseEntity for full response control in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to return a ResponseEntity with status 200 OK.

Spring Boot

return ResponseEntity.[1]().body("Success");

Drag options to blanks, or click blank then click option'

Aok

Bstatus

Cbuild

Dcreate

Attempts:

3 left

💡 Hint

Common Mistakes

Using methods like status() without specifying status code.

Trying to use build() without setting status.

The ok() method creates a ResponseEntity with HTTP status 200 OK.

2fill in blank

medium

Complete the code to set the HTTP status to 404 NOT FOUND.

Spring Boot

return ResponseEntity.status(HttpStatus.[1]).body("Not Found");

Drag options to blanks, or click blank then click option'

AOK

BCREATED

CBAD_REQUEST

DNOT_FOUND

Attempts:

3 left

💡 Hint

Common Mistakes

Using OK or CREATED which are 200 and 201 statuses.

Using BAD_REQUEST which is 400.

The NOT_FOUND status corresponds to HTTP 404.

3fill in blank

hard

Fix the error in setting a custom header in ResponseEntity.

Spring Boot

return ResponseEntity.ok().header("[1]", "application/json").body(data);

Drag options to blanks, or click blank then click option'

AAccept

BContent-Type

Ccontent-type

DAuthorization

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase 'content-type' which may cause confusion.

Using unrelated headers like Accept or Authorization.

HTTP headers are case-insensitive but conventionally use 'Content-Type' with capital letters.

4fill in blank

hard

Fill both blanks to create a ResponseEntity with status 201 CREATED and a Location header.

Spring Boot

return ResponseEntity.status(HttpStatus.[1]).header("[2]", "/items/123").build();

Drag options to blanks, or click blank then click option'

ACREATED

BLocation

Ccontent-type

Dok

Attempts:

3 left

💡 Hint

Common Mistakes

Using ok() instead of CREATED.

Using content-type header instead of Location.

The ResponseEntity.status(HttpStatus.CREATED) sets status 201, and the Location header tells where the new resource is.

5fill in blank

hard

Fill all three blanks to return a ResponseEntity with status 204 NO CONTENT, a custom header, and no body.

Spring Boot

return ResponseEntity.[1]().header("[2]", "no-cache").[3]();

Drag options to blanks, or click blank then click option'

AnoContent

BCache-Control

Cbuild

Dbody

Attempts:

3 left

💡 Hint

Common Mistakes

Using body() which requires a body for 204 status.

Using wrong header names.

noContent() sets HTTP 204 status, Cache-Control is a header for caching, and build() completes the response without a body.

Practice

1. What is the main purpose of using ResponseEntity in a Spring Boot REST controller?

easy

A. To control the HTTP status, headers, and body of the response

B. To automatically map JSON to Java objects

C. To handle database transactions

D. To configure application properties

Solution

1. Step 1: Understand ResponseEntity role

   ResponseEntity is designed to give full control over HTTP response details like status code, headers, and body.

2. Step 2: Compare with other options

   Mapping JSON, handling transactions, or configuring properties are unrelated to ResponseEntity's purpose.

3. Final Answer:

   To control the HTTP status, headers, and body of the response -> Option A

4. Quick Check:

   ResponseEntity controls full HTTP response [OK]

Hint: ResponseEntity controls status, headers, and body [OK]

Common Mistakes:

• Confusing ResponseEntity with JSON mapping
• Thinking it manages database operations
• Assuming it configures app settings

2. Which of the following is the correct way to create a ResponseEntity with status 404 and a body message "Not Found"?

easy

A. return ResponseEntity.create(404, "Not Found");

B. return ResponseEntity.body("Not Found").status(404);

C. return new ResponseEntity<>("Not Found", 404);

D. return ResponseEntity.status(404).body("Not Found");

Solution

1. Step 1: Check ResponseEntity builder methods

   The correct builder pattern is to call status() first, then body().

2. Step 2: Validate options

   return ResponseEntity.status(404).body("Not Found"); uses status(404).body("Not Found") correctly. return ResponseEntity.body("Not Found").status(404); reverses the order, which is invalid. return new ResponseEntity<>("Not Found", 404); uses a constructor but 404 should be HttpStatus, not int. return ResponseEntity.create(404, "Not Found"); uses a non-existent method.

3. Final Answer:

   return ResponseEntity.status(404).body("Not Found"); -> Option D

4. Quick Check:

   Use status().body() chaining [OK]

Hint: Call status() before body() to build ResponseEntity [OK]

Common Mistakes:

• Calling body() before status()
• Using integer instead of HttpStatus enum
• Using non-existent ResponseEntity methods

3. Given the code snippet:

return ResponseEntity.status(HttpStatus.CREATED)
    .header("Location", "/items/123")
    .body("Item created");

What will be the HTTP status and headers in the response?

medium

A. Status 201 Created with no headers

B. Status 201 Created with header Location: /items/123

C. Status 200 OK with header Location: /items/123

D. Status 404 Not Found with header Location: /items/123

Solution

1. Step 1: Analyze status method

   The code sets status to HttpStatus.CREATED which is 201.

2. Step 2: Analyze header method

   The header method adds a "Location" header with value "/items/123".

3. Final Answer:

   Status 201 Created with header Location: /items/123 -> Option B

4. Quick Check:

   Status = 201, Header Location set [OK]

Hint: status() sets code, header() adds headers [OK]

Common Mistakes:

• Assuming default 200 OK status
• Forgetting headers are added by header()
• Confusing status codes meanings

4. Identify the error in this Spring Boot controller method:

@GetMapping("/test")
public ResponseEntity<String> test() {
    return ResponseEntity.body("Hello").status(HttpStatus.OK);
}

medium

A. HttpStatus.OK is not a valid status

B. ResponseEntity.body() cannot be used without new keyword

C. The order of method calls is incorrect; status() must come before body()

D. The method must return String, not ResponseEntity

Solution

1. Step 1: Check method chaining order

   ResponseEntity builder requires calling status() before body(). Here, body() is called first, which is invalid.

2. Step 2: Validate other options

   ResponseEntity.body() is a static method returning a builder, no new keyword needed. HttpStatus.OK is valid. Returning ResponseEntity<String> is correct for REST.

3. Final Answer:

   The order of method calls is incorrect; status() must come before body() -> Option C

4. Quick Check:

   Call status() before body() [OK]

Hint: Always call status() before body() in ResponseEntity [OK]

Common Mistakes:

• Calling body() before status()
• Trying to instantiate ResponseEntity with new
• Confusing return types in controller

5. You want to return a JSON response with status 202 Accepted, a custom header "X-Request-ID" set to "abc123", and a body containing a Map with key "message" and value "Processing". Which code snippet correctly achieves this?

hard

A. return ResponseEntity.status(HttpStatus.ACCEPTED)
.header("X-Request-ID", "abc123")
.body(Map.of("message", "Processing"));

B. return ResponseEntity.body(Map.of("message", "Processing"))
.header("X-Request-ID", "abc123")
.status(HttpStatus.ACCEPTED);

C. return new ResponseEntity<>(Map.of("message", "Processing"), HttpStatus.ACCEPTED, Map.of("X-Request-ID", "abc123"));

D. return ResponseEntity.create(HttpStatus.ACCEPTED, Map.of("message", "Processing"))
.header("X-Request-ID", "abc123");

Solution

1. Step 1: Use correct builder pattern

   ResponseEntity builder requires calling status() first, then header(), then body().

2. Step 2: Validate options

   return ResponseEntity.status(HttpStatus.ACCEPTED) .header("X-Request-ID", "abc123") .body(Map.of("message", "Processing")); follows correct chaining and uses Map.of for body. return ResponseEntity.body(Map.of("message", "Processing")) .header("X-Request-ID", "abc123") .status(HttpStatus.ACCEPTED); calls body() first, invalid order. return new ResponseEntity<>(Map.of("message", "Processing"), HttpStatus.ACCEPTED, Map.of("X-Request-ID", "abc123")); uses a constructor with three arguments which does not exist. return ResponseEntity.create(HttpStatus.ACCEPTED, Map.of("message", "Processing")) .header("X-Request-ID", "abc123"); uses a non-existent create() method.

3. Final Answer:

   return ResponseEntity.status(HttpStatus.ACCEPTED) .header("X-Request-ID", "abc123") .body(Map.of("message", "Processing")); -> Option A

4. Quick Check:

   status() -> header() -> body() chaining [OK]

Hint: Chain status(), then header(), then body() for full control [OK]

Common Mistakes:

• Calling body() before status()
• Using non-existent ResponseEntity constructors
• Trying to use create() method which doesn't exist