LDT Technology Junior Java Developer Interview Questions and Answers

Spring Framework is a popular Java framework that provides comprehensive infrastructure support for developing Java applications.

• Provides dependency injection for managing components

• Offers support for aspect-oriented programming

• Includes modules for data access, web development, security, and more

• Facilitates integration with other frameworks like Hibernate and JPA

An interface in Java is a reference type, similar to a class, that can contain only constants, method signatures, default methods, static methods, and nested types.

• Interfaces are used to define a contract for classes that implement them.

• Classes can implement multiple interfaces, but can only extend one class.

• Interfaces are used to achieve abstraction and multiple inheritance in Java.

• Example: interface Animal { void eat...read more

Polymorphism is the ability of a single function or method to operate on different types of data.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass.

• There are two types of polymorphism: compile-time (method overloading) and runtime (method overriding).

• Example: Animal superclass with Dog and Cat subclasses, both implementing a makeSound method differently.

Types of exceptions include checked, unchecked, and errors.

• Checked exceptions are checked at compile time, like IOException.

• Unchecked exceptions are not checked at compile time, like NullPointerException.

• Errors are serious problems that should not be caught, like OutOfMemoryError.

Multithreading is the ability of a CPU to execute multiple threads concurrently, allowing for parallel processing.

• Multithreading allows for better utilization of CPU resources by running multiple threads simultaneously.

• Threads share the same memory space, allowing for communication and data sharing between threads.

• Examples of multithreading in Java include creating multiple threads to perform different tasks concurrent...read more