Northcorp Software Java Developer Interview Questions and Answers

JavaMail is an API for sending and receiving emails in Java applications, supporting various protocols like SMTP, IMAP, and POP3.

• JavaMail API allows developers to send and receive emails programmatically.

• It supports multiple protocols: SMTP for sending, IMAP and POP3 for receiving.

• Example of sending an email using JavaMail: Properties props = new Properties(); props.put('mail.smtp.host', 'smtp.example.com'...read more

Multithreading is a programming technique that allows concurrent execution of two or more threads for improved performance.

• Multithreading enables parallel execution, improving application responsiveness.

• Java provides built-in support for multithreading through the Thread class and Runnable interface.

• Example: A web server can handle multiple client requests simultaneously using threads.

• Synchronization is crucial to...read more

Inheritance is a fundamental OOP concept allowing a class to inherit properties and methods from another class.

• Promotes code reusability by allowing a new class (subclass) to use methods and attributes of an existing class (superclass).

• Supports method overriding, enabling subclasses to provide specific implementations of methods defined in the superclass.

• Facilitates a hierarchical classification of classes, making...read more

SDLC (Software Development Life Cycle) is a structured process for developing software applications efficiently.

• 1. Requirement Analysis: Gathering and analyzing user requirements.

• 2. Planning: Defining the scope, resources, and timeline for the project.

• 3. Design: Creating architecture and design specifications for the software.

• 4. Implementation: Writing and compiling the code based on design specifications.

• 5. Testi...read more

Method overloading allows defining multiple methods with the same name but different parameters.

• Methods must have different parameter types or number of parameters.

• Return type does not matter for method overloading.

• Example: void print(int num) and void print(String text) are valid overloads.

D/W HashMap is a standard map, while ConcurrentHashMap is thread-safe for concurrent access in Java.

• HashMap allows null keys and values, while ConcurrentHashMap does not allow null keys or values.

• HashMap is not synchronized, making it unsuitable for concurrent use without external synchronization.

• ConcurrentHashMap uses a lock striping technique, allowing concurrent read and write operations.

• Example of HashMap: Has...read more