Grouping APIs by tags in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add a tag to the API using Swagger annotations.

Spring Boot

@Tag(name = "[1]")
@RestController
public class UserController {
    // API methods
}

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

AAPI

BUserController

CController

DUser Management

Attempts:

3 left

💡 Hint

Common Mistakes

Using the controller class name as the tag name.

Leaving the tag name empty.

Using generic names like 'API' or 'Controller'.

The @Tag annotation groups APIs under the given name in Swagger UI.

2fill in blank

medium

Complete the code to add a tag description for better API grouping.

Spring Boot

@Tag(name = "User Management", description = "[1]")
@RestController
public class UserController {
    // API methods
}

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

AAPI endpoints

BUser APIs

CHandles user related operations

DController for users

Attempts:

3 left

💡 Hint

Common Mistakes

Using vague or short descriptions.

Repeating the tag name as description.

Leaving description empty.

The description attribute in @Tag provides a clear explanation of the API group.

3fill in blank

hard

Fix the error in the tag annotation to correctly group APIs.

Spring Boot

@Tag(name = "User Management", description = [1])
@RestController
public class UserController {
    // API methods
}

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

A"Handles user related operations"

BHandles user related operations

C'Handles user related operations'

DHandles user operations

Attempts:

3 left

💡 Hint

Common Mistakes

Missing quotes around the description string.

Using single quotes instead of double quotes.

Passing a variable instead of a string literal.

The description value must be a string literal enclosed in double quotes in Java annotations.

4fill in blank

hard

Fill both blanks to tag multiple APIs in different controllers.

Spring Boot

@Tag(name = "[1]")
@RestController
public class ProductController {
    // Product APIs
}

@Tag(name = "[2]")
@RestController
public class OrderController {
    // Order APIs
}

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

AProduct Management

BOrder Management

CUser Management

DInventory

Attempts:

3 left

💡 Hint

Common Mistakes

Using the same tag name for different controllers.

Using unrelated tag names.

Leaving tag names generic.

Each controller should have a tag that groups its APIs logically by their domain.

5fill in blank

hard

Fill all three blanks to add tags with names and descriptions to APIs.

Spring Boot

@Tag(name = "[1]", description = "[2]")
@RestController
public class CustomerController {
    // Customer APIs
}

@Tag(name = "[3]")
@RestController
public class InvoiceController {
    // Invoice APIs
}

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

ACustomer Management

BManages customer related operations

CInvoice Management

DHandles invoice processing

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing tag names and descriptions incorrectly.

Omitting quotes around description strings.

Using unrelated tag names.

Tags group APIs by name and can include descriptions for clarity. The InvoiceController tag here has only a name.

Practice

1. What is the main purpose of using @Tag annotation in Spring Boot controllers?

easy

A. To specify the database table for the API

B. To group related APIs for better documentation organization

C. To define the HTTP method of an API endpoint

D. To secure APIs with authentication

Solution

1. Step 1: Understand the role of @Tag

   The @Tag annotation is used to group APIs logically in documentation tools like Swagger.

2. Step 2: Identify its effect on API docs

   Grouping APIs by tags makes the documentation easier to read and navigate for users.

3. Final Answer:

   To group related APIs for better documentation organization -> Option B

4. Quick Check:

   @Tag groups APIs = D [OK]

Hint: Remember @Tag groups APIs for docs, not for security or DB [OK]

Common Mistakes:

• Confusing @Tag with security annotations
• Thinking @Tag sets HTTP methods
• Assuming @Tag relates to database mapping

2. Which of the following is the correct way to add a tag named "User Management" to a Spring Boot controller?

easy

A. @Tag(name = "User Management") above the controller class

B. @Tag(value = "User Management") above each method

C. @Tag("User Management") inside the method body

D. @Tag(name = "User Management") inside the application.properties file

Solution

1. Step 1: Identify correct @Tag usage

   The @Tag annotation is placed above the controller class with the name attribute to specify the tag.

2. Step 2: Confirm placement and syntax

   It should not be inside methods or properties files; it applies at the class level for grouping all endpoints.

3. Final Answer:

   @Tag(name = "User Management") above the controller class -> Option A

4. Quick Check:

   @Tag(name=...) on class = A [OK]

Hint: Place @Tag(name=...) above controller class, not methods or config [OK]

Common Mistakes:

• Using @Tag inside method bodies
• Using 'value' instead of 'name' attribute
• Placing @Tag in properties files

3. Given this controller code snippet:

@RestController
@Tag(name = "Orders")
public class OrderController {
  @GetMapping("/orders")
  public List<String> getOrders() { return List.of("order1", "order2"); }
}

What tag will appear in the generated API documentation for the /orders endpoint?

medium

A. "Orders"

B. No tag will appear

C. "OrderController"

D. "getOrders"

Solution

1. Step 1: Check @Tag annotation on controller

   The controller class has @Tag(name = "Orders"), so all its endpoints inherit this tag.

2. Step 2: Determine tag shown in docs

   The /orders endpoint will be grouped under the "Orders" tag in the API documentation.

3. Final Answer:

   "Orders" -> Option A

4. Quick Check:

   Controller @Tag name = "Orders" means tag = B [OK]

Hint: Controller-level @Tag sets tag for all its endpoints [OK]

Common Mistakes:

• Expecting method name as tag
• Thinking no tag appears without method-level @Tag
• Confusing class name with tag

4. Consider this controller code:

@RestController
@Tag(name = "Products")
public class ProductController {
  @GetMapping("/products")
  public List<String> getProducts() { return List.of("prod1", "prod2"); }

  @Tag(name = "Special")
  @GetMapping("/products/special")
  public List<String> getSpecialProducts() { return List.of("special1"); }
}

What is the problem with this code regarding API grouping by tags?

medium

A. Multiple @Tag annotations cause runtime errors

B. Method-level @Tag overrides class-level @Tag correctly

C. @Tag cannot be used on methods, causing a compile error

D. Method-level @Tag is ignored; only class-level @Tag works

Solution

1. Step 1: Check @Tag usage rules

   In Spring Boot with OpenAPI, @Tag is primarily for class-level use to group endpoints. Method-level @Tag is ignored for grouping purposes.

2. Step 2: Identify its effect on API docs

   The /products/special endpoint will still be grouped under the "Products" tag, as method-level @Tag does not override class-level grouping.

3. Final Answer:

   Method-level @Tag is ignored; only class-level @Tag works -> Option D

4. Quick Check:

   Method-level @Tag ignored = A [OK]

Hint: Use @Tag only on controller classes, not on methods [OK]

Common Mistakes:

• Assuming method-level @Tag overrides class-level
• Thinking multiple @Tag annotations cause runtime errors
• Ignoring that method-level @Tag is invalid

5. You have two controllers:

@RestController
@Tag(name = "Users")
public class UserController {
  @GetMapping("/users")
  public List<String> getUsers() { return List.of("user1", "user2"); }
}

@RestController
@Tag(name = "Admins")
public class AdminController {
  @GetMapping("/admins")
  public List<String> getAdmins() { return List.of("admin1"); }
}

How will the API documentation group these endpoints?

hard

A. No tags will appear in the documentation

B. All endpoints under a single "Users" tag

C. Endpoints grouped separately under "Users" and "Admins" tags

D. Endpoints grouped under controller class names as tags

Solution

1. Step 1: Identify tags on each controller

   UserController has @Tag(name = "Users") and AdminController has @Tag(name = "Admins").

2. Step 2: Understand grouping in docs

   Each controller's endpoints are grouped under their respective tags in the API docs.

3. Final Answer:

   Endpoints grouped separately under "Users" and "Admins" tags -> Option C

4. Quick Check:

   Separate @Tag names create separate groups = A [OK]

Hint: Different @Tag names on controllers create separate groups [OK]

Common Mistakes:

• Assuming all endpoints merge under one tag
• Expecting no tags without method-level @Tag
• Thinking controller class names become tags automatically