Senior Java Software Engineer Interview Questions and Answers

ResultSet is an interface in Java used to retrieve data from a database. It should be avoided due to its performance issues.

• ResultSet is used to retrieve data from a database in Java

• It has performance issues and should be avoided if possible

• Alternative options like JPA or Hibernate can be used instead

Collections are a group of classes and interfaces used to store and manipulate groups of objects in Java.

• Collections provide a way to store and manipulate groups of objects in Java

• They offer various data structures like List, Set, Map, etc.

• Collections provide methods to add, remove, and search for elements in the data structures

• They also offer algorithms for sorting and searching elements

• Examples include ArrayList, HashSet, TreeMap, etc.

Java is a high-level programming language used to develop applications that can run on any platform.

• Java code is compiled into bytecode that can run on any platform with a Java Virtual Machine (JVM)

• JVM acts as an interpreter and translates bytecode into machine code

• Java's platform independence is achieved through the 'Write Once, Run Anywhere' (WORA) principle

• Java's standard library provides platform-independent APIs for common tasks

Some annotations used in Spring Boot projects are @RestController, @Autowired, @RequestMapping, @Service, @Component, @Repository.

• @RestController - Used to define RESTful web services.

• @Autowired - Used for automatic dependency injection.

• @RequestMapping - Used to map web requests to specific handler methods.

• @Service - Used to indicate that a class is a service.

• @Component - Used to indicate that a class is a Spring component.

• @Repository - Used to indicate that a class is a repo...read more

Static variable is a variable that belongs to the class and not to the instance of the class.

• Static variables are declared using the 'static' keyword.

• They are initialized only once, at the start of the program.

• They can be accessed using the class name, without creating an instance of the class.

• Changes made to a static variable are reflected across all instances of the class.

• Example: 'public static int count = 0;'

Serialization is the process of converting an object into a stream of bytes to store or transmit it.

• Serialization is used to save and restore object states

• Java provides Serializable interface to implement serialization

• Serialization can be used for inter-process communication and distributed systems

• Deserialization is the process of converting a stream of bytes back into an object

• Serialization can be customized using readObject() and writeObject() methods

Design a parking lot system for efficient management of parking spaces.

• Use object-oriented design principles to create classes for parking lot, parking space, vehicle, etc.

• Implement algorithms for efficient parking space allocation and retrieval.

• Incorporate features like ticketing system, payment processing, and monitoring.

• Consider scalability and performance optimization for handling a large number of vehicles.

• Include a user-friendly interface for drivers to easily navigate ...read more