Java Programming — MCQ Practice Questions & Answers

Question 1

An enterprise application needs different bean implementations based on environment (dev/prod). Which approach is most suitable?

Accepted Answer

Correct answer: C. @Profile annotation to define environment-specific beans — @Profile allows defining beans for specific environments (dev, prod, test). Alternatively, @Conditional provides more granular control with custom conditions.

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A. @Bean with conditional logic inside @Configuration

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B. @Conditional annotation with custom conditions

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D. Manual bean creation in main() method

Question 2

What happens when a prototype-scoped bean has a dependency on a singleton-scoped bean in Spring?

Accepted Answer

Correct answer: B. The singleton bean is correctly injected into each prototype instance — A prototype bean can depend on singleton beans without issues. Each prototype instance gets the same singleton instance injected. The reverse (singleton depending on prototype) is problematic.

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A. Compilation error occurs

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C. The prototype bean becomes singleton

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D. A runtime exception is thrown

Question 3

In Spring Framework 2024-25, which feature allows lazy initialization of beans?

Accepted Answer

Correct answer: A. @Lazy annotation on @Bean or @Component — @Lazy annotation (available in modern Spring versions) marks beans for lazy initialization. It can be used on class level or with @Bean methods. XML also supports lazy-init attribute.

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B. @DeferredInit annotation

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C. Setting lazy-init='true' only in XML

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D. Spring automatically detects and lazily initializes all beans

Question 4

A microservices architecture uses Spring with circular dependency between ServiceA and ServiceB. What is the best solution?

Accepted Answer

Correct answer: B. Refactor to introduce a third service or use setter injection with @Lazy — Circular dependencies indicate design issues. Best solutions: refactor code, use setter injection (instead of constructor) combined with @Lazy, or introduce an intermediary service to break the cycle.

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A. Increase heap memory to handle circular references

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C. Use @Autowired on both constructor and setter

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D. Switch to manual bean management

Question 5

How does Spring handle circular dependency between two beans?

Accepted Answer

Correct answer: A. Automatically resolves it using setter injection for one of the beans — Spring can resolve circular dependencies when at least one injection is done via setter method rather than constructor, allowing lazy initialization.

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B. Throws BeanCurrentlyInCreationException at startup

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C. Silently ignores one of the dependencies

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D. Uses a proxy pattern to defer initialization of one bean

Question 6

An enterprise application requires different bean implementations based on runtime conditions. Which Spring feature is most suitable?

Accepted Answer

Correct answer: D. All of the above can be used depending on the scenario — @Conditional provides fine-grained control, @Profile handles environment-specific beans, and factory beans offer explicit creation logic. Choice depends on use case requirements.

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A. @Conditional annotation with custom Condition implementations

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B. @Profile annotation for environment-specific beans

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C. Factory pattern with factory beans

Question 7

Consider a Spring application where method execution time tracking is required across multiple methods. Which approach is most appropriate?

Accepted Answer

Correct answer: A. Using Spring AOP with custom aspect to track execution time — Spring AOP with a custom aspect provides centralized, reusable cross-cutting concern implementation without code duplication in individual methods.

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B. Adding timing logic manually in each method

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C. Using @Timed annotation from Spring Actuator

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D. Implementing a custom servlet filter

Question 8

In Spring framework, what is the purpose of FactoryBean interface?

Accepted Answer

Correct answer: A. To create complex bean instances with custom initialization logic — FactoryBean allows creating beans with sophisticated initialization logic through getObject() method, useful for complex object creation.

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B. To define factory methods for creating beans

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C. To implement the Factory design pattern

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D. To manage bean lifecycle events

Java Programming - MCQ Practice Questions