Infinite Computer Solutions Java Developer Interview Questions and Answers

Developed a web-based inventory management system for a retail company.

• Used Java, Spring Boot, and MySQL for backend development.

• Implemented user authentication and authorization using Spring Security.

• Designed a responsive front-end using HTML, CSS, and JavaScript.

• Integrated barcode scanning functionality for efficient inventory tracking.

A class is a blueprint or template for creating objects, while an object is an instance of a class.

• A class defines the properties and behaviors of objects, while an object is a specific instance of a class.

• Classes can be used to create multiple objects with similar characteristics.

• Objects have state (attributes) and behavior (methods) defined by the class.

• Example: Class 'Car' defines properties like 'color' and 'model'...read more

Filter out strings starting with 'a' and convert to uppercase using Streams

• Use Stream.filter() to filter out strings starting with 'a'

• Use Stream.map() to convert remaining strings to uppercase

• Collect the result back into an array using Collectors.toList()

Implement a SQL query for given examples

• Use SELECT statement to retrieve data from tables

• Use WHERE clause to filter results based on conditions

• Use JOIN clause to combine data from multiple tables if needed

Comparable is an interface used for natural ordering, while Comparator is used for custom ordering in Java.

• Comparable interface is used to define the natural ordering of objects. It is implemented by the class whose objects are to be sorted.

• Comparator interface is used to define custom ordering of objects. It is implemented by a separate class that compares objects based on specific criteria.

• Example: Sorting a list of ...read more

List allows duplicate elements and maintains insertion order, while Set does not allow duplicates and does not maintain order.

• List can contain duplicate elements, Set cannot

• List maintains insertion order, Set does not guarantee order

• List is implemented by classes like ArrayList, LinkedList, Set is implemented by classes like HashSet, TreeSet

• Example: List list = new ArrayList<>(); Set set = new HashSet<>();