HEPL - A Cavinkare Group Company Java Developer Interview Questions and Answers

Exception handling in Java involves using try-catch blocks to manage errors gracefully and maintain application stability.

• Use try-catch blocks to catch exceptions: try { // code that may throw an exception } catch (ExceptionType e) { // handle exception }

• Use finally block for cleanup: try { // code } catch (Exception e) { // handle exception } finally { ...read more

Microservices communicate via APIs, messaging queues, or event-driven architectures to share data efficiently.

• 1. RESTful APIs: Services expose endpoints for data retrieval. Example: Service A calls Service B's API to get user details.

• 2. Messaging Queues: Use tools like RabbitMQ or Kafka for asynchronous communication. Example: Service A sends a message to a queue that Service B listens to.

• 3. gRPC: A high-performan...read more

Inner join is used to combine rows from two or more tables based on a related column between them.

• Use INNER JOIN keyword in SQL to perform inner join

• Specify the columns to join on using ON keyword

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column

For loop is used to iterate over a collection of elements in Java.

• Syntax: for(initialization; condition; update) { // code block }

• Example: for(int i=0; i<10; i++) { System.out.println(i); }

A for loop is a control flow statement for executing a block of code repeatedly based on a condition.

• Syntax: for(initialization; condition; increment/decrement) { // code block }

• Example: for(int i = 0; i < 5; i++) { System.out.println(i); } // prints 0 to 4

• Used for iterating over arrays or collections.

• Can be nested: for(int i = 0; i < 3; i++) { for(int j = 0; j < 2; j++) { // code block } }

• Enhanced for lo...read more

Multithreading is the concurrent execution of two or more threads to achieve maximum utilization of CPU.

• Multithreading allows multiple threads to run concurrently within a single program.

• It improves performance by utilizing idle CPU time and allows for better responsiveness in applications.

• Threads can be created by extending the Thread class or implementing the Runnable interface.

• Example: A web server handling mul...read more