🌱 Spring Boot MCQ Questions – Page 49

Questions 961–971 of 971 total — Spring Boot interview practice

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Q961 medium
When a method annotated with `@GetMapping` inside a `@Controller` returns a `String` (e.g., `"products/list"`), what does Spring Boot typically do with this string?
Q962 medium code output
What is the HTTP response body when a GET request is made to `/config/theme/dark`?
java 
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import java.util.Map;

@RestController
public class ConfigController {
    @GetMapping("/config/{key}/{value}")
    public String setConfig(@PathVariable Map<String, String> pathVars) {
        return "Config set: " + pathVars.get("key") + " = " + pathVars.get("value");
    }
}
Q963 medium
Which HTTP status code is most appropriate to return from a Spring Boot DELETE endpoint when a resource has been successfully deleted and there is no content to send in the response body?
Q964 medium code error
What is the expected behavior if a Spring Boot controller returns a view name that includes a path like `/templates/home` instead of just `home`, assuming Thymeleaf is configured by default and `home.html` is in `src/main/resources/templates/`?
java 
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.ui.Model;

@Controller
public class HomeController {

    @GetMapping("/home")
    public String displayHome(Model model) {
        model.addAttribute("greeting", "Welcome!");
        return "/templates/home"; // Incorrect path prefix
    }
}
Q965 medium code error
Given the following Spring configuration, what error will be thrown during application context initialization?
java 
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class AppConfig {
    @Bean(name = "mySharedBean")
    public String beanA() {
        return "Value A";
    }

    @Bean(name = "mySharedBean")
    public Integer beanB() {
        return 123;
    }
}
Q966 medium
How can you inject a simple string property named `app.name` from `application.properties` into a Spring component field?
Q967 medium
What is the consequence of setting `required = false` in `@Autowired`, e.g., `@Autowired(required = false)`?
Q968 medium code output
What does this code print?
java 
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;

interface NotificationService { String send(); }
@Component("emailService") static class EmailNotificationService implements NotificationService { @Override public String send() { return "Sending Email"; } }
@Component("smsService") static class SmsNotificationService implements NotificationService { @Override public String send() { return "Sending SMS"; } }

@SpringBootApplication
public class MyApplication {
    @Autowired @Qualifier("smsService")
    private NotificationService notificationService;
    public static void main(String[] args) {
        MyApplication app = SpringApplication.run(MyApplication.class, args).getBean(MyApplication.class);
        System.out.println(app.notificationService.send());
    }
}
Q969 medium code output
Consider the following Spring Boot utility class for JWT. What will be printed when parsing a token signed with a *different* secret key?
java 
import io.jsonwebtoken.*;
import io.jsonwebtoken.security.Keys;
import java.security.Key;
import java.util.Date;

public class JwtUtil {
    public static void main(String[] args) {
        Key correctKey = Keys.secretKeyFor(SignatureAlgorithm.HS256);
        Key wrongKey = Keys.secretKeyFor(SignatureAlgorithm.HS256);
        String token = Jwts.builder().setSubject("user").signWith(correctKey).compact();
        try {
            Jwts.parserBuilder().setSigningKey(wrongKey).build().parseClaimsJws(token);
            System.out.println("Token is valid");
        } catch (SignatureException e) {
            System.out.println("SignatureException caught");
        } catch (Exception e) {
            System.out.println("Other exception: " + e.getClass().getSimpleName());
        }
    }
}
Q970 medium
Can a single Spring Boot controller method typically have multiple parameters annotated with `@RequestBody`?
Q971 medium code output
What is the result when this Spring Boot application attempts to start?
java 
import org.springframework.stereotype.Component;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.CommandLineRunner;

interface GreetingService {
    String greet();
}

@Component
class EnglishGreetingService implements GreetingService {
    @Override public String greet() { return "Hello!"; }
}

@Component
class SpanishGreetingService implements GreetingService {
    @Override public String greet() { return "Hola!"; }
}

@Component
class MyRunner implements CommandLineRunner {
    @Autowired
    private GreetingService service;

    @Override
    public void run(String... args) {
        System.out.println(service.greet());
    }
}

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