@RequestMapping for base paths in Spring Boot - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the base URL path for this controller?

Given the following Spring Boot controller code, what is the base URL path that all methods inside this controller will respond to?

Spring Boot

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/api/v1/users")
public class UserController {

    @RequestMapping("/list")
    public String listUsers() {
        return "User list";
    }

    @RequestMapping("/detail")
    public String userDetails() {
        return "User details";
    }
}

A /list

B /detail

C /api/v1/users/list

D /api/v1/users

💡 Hint

Look at the @RequestMapping annotation on the class level.

The @RequestMapping annotation on the class sets the base path for all methods inside the controller. Here, it is /api/v1/users. The methods add to this base path.

❓ state_output

intermediate

What URL path does the listUsers() method respond to?

Using the same controller code, what is the full URL path that the listUsers() method will respond to?

Spring Boot

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/api/v1/users")
public class UserController {

    @RequestMapping("/list")
    public String listUsers() {
        return "User list";
    }

    @RequestMapping("/detail")
    public String userDetails() {
        return "User details";
    }
}

A /api/v1/users/list

B /api/v1/users/detail

C /api/v1/users

D /list

💡 Hint

Combine the class-level and method-level @RequestMapping paths.

The full URL path is the base path from the class /api/v1/users plus the method path /list, resulting in /api/v1/users/list.

📝 Syntax

advanced

Which option correctly sets a base path with multiple paths in @RequestMapping?

You want your controller to respond to two base paths: "/api/v1/users" and "/users". Which @RequestMapping annotation syntax correctly sets this?

A @RequestMapping({"/api/v1/users", "/users"})

B @RequestMapping("/api/v1/users", "/users")

C @RequestMapping(path = "/api/v1/users", path = "/users")

D @RequestMapping(value = "/api/v1/users" & "/users")

💡 Hint

Check how to specify multiple paths in an array for @RequestMapping.

To specify multiple paths, use an array of strings inside curly braces: {"/api/v1/users", "/users"}. Option A is correct.

🔧 Debug

advanced

What error occurs with this incorrect @RequestMapping usage?

Consider this controller code snippet: @RestController @RequestMapping("/api/v1/users") public class UserController { @RequestMapping public String listUsers() { return "User list"; } @RequestMapping("/detail") public String userDetails() { return "User details"; } } What happens when you try to access "/api/v1/users" in the browser?

A 500 Internal Server Error due to missing method path

B Returns "User list" because method-level @RequestMapping with no path matches base path

C 404 Not Found error because method-level @RequestMapping requires a path

D Compilation error because @RequestMapping must have a path

💡 Hint

Method-level @RequestMapping without a path matches the base path.

If a method has @RequestMapping without a path, it matches the base path set by the class-level @RequestMapping. So accessing "/api/v1/users" returns "User list".

🧠 Conceptual

expert

How does @RequestMapping at class and method levels combine for HTTP methods?

Given this controller snippet: @RestController @RequestMapping(path = "/api/v1/items", method = RequestMethod.GET) public class ItemController { @RequestMapping(path = "/create", method = RequestMethod.POST) public String createItem() { return "Item created"; } @RequestMapping(path = "/list") public String listItems() { return "Item list"; } } Which HTTP methods and paths are valid for these two methods?

A createItem: POST /api/v1/items/create; listItems: POST /api/v1/items/list

B createItem: GET /api/v1/items/create; listItems: GET /api/v1/items/list

C createItem: POST /api/v1/items/create; listItems: GET /api/v1/items/list

D createItem: GET /api/v1/items/create; listItems: POST /api/v1/items/list

💡 Hint

Method-level @RequestMapping overrides HTTP method from class-level if specified.

The class-level @RequestMapping sets GET as default method for all paths. The createItem method overrides this with POST. The listItems method inherits GET from the class.