Which of the following is a thread-safe collection in Java that can be used without explicit synchronization?

The correct answer is C: ConcurrentHashMap. ConcurrentHashMap is designed for concurrent access and is thread-safe. ArrayList, HashMap, and TreeMap require external synchronization for thread safety.

In Java NIO, which class is used for channel-based I/O?

The correct answer is B: FileChannel. FileChannel provides non-blocking and efficient I/O operations, memory-mapped file access, and file locking capabilities compared to traditional streams.

What will happen with this code? List list = new ArrayList(); list.add(123); // Adding Integer String s = (String) list.get(0);

The correct answer is A: ClassCastException at runtime. Raw type List accepts any object. At runtime, the Integer 123 cannot be cast to String, causing ClassCastException.

Which class in Java is used to read primitive data types from a binary stream?

The correct answer is A: DataInputStream. DataInputStream is specifically designed to read primitive data types (int, float, double, etc.) from a binary stream using methods like readInt(), readFloat(), etc.

Which of the following best describes the purpose of the Runnable interface in Java?

The correct answer is B: It provides a way to define code that can be executed by a thread. The Runnable interface contains a single run() method that defines the code to be executed when a thread runs. It's preferred over extending Thread class.

Home

Home › Subjects › Java Programming › Spring Framework Basics

Java Programming
Spring Framework Basics

Java OOP, collections, multithreading

12 Q 10 Topics Take Mock Test

Difficulty: All Easy Medium Hard 11–12 of 12

Topics in Java Programming

All Basics & Syntax 100 OOP in Java 100 Collections Framework 100 Multithreading 100 Exception Handling 100 I/O Streams 100 JDBC 100 Generics 100 Lambda Expressions 100 Spring Framework Basics 58

Q.11 Hard Spring Framework Basics

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

A Compilation error occurs

B The singleton bean is correctly injected into each prototype instance

C The prototype bean becomes singleton

D A runtime exception is thrown

Correct Answer: B. The singleton bean is correctly injected into each prototype instance

EXPLANATION

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.

Test

Q.12 Hard Spring Framework Basics

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

A @Bean with conditional logic inside @Configuration

B @Conditional annotation with custom conditions

C @Profile annotation to define environment-specific beans

D Manual bean creation in main() method

Correct Answer: C. @Profile annotation to define environment-specific beans

EXPLANATION

@Profile allows defining beans for specific environments (dev, prod, test). Alternatively, @Conditional provides more granular control with custom conditions.

Test

1 2

All Subjects & Topics

Govt. Exams

Entrance Exams

Teacher Exams

Subjects

Quick Links

Java Programming Spring Framework Basics

Java Programming
Spring Framework Basics