Important Java interview questions you should prepare in 2021

In this article we’ve collected the most commonly asked Java Interview Questions for freshers and job seekers in Java. These questions will familiarize you with the types of questions an interviewer will ask you during your Java Programming interview. As a Fresher, you have either attended or will soon attend an interview. You may be worried about the upcoming interviews as an Entry Level job seeker trying to advance your career in software programming. If you want to start a career in Java web app development, you’ve come to the right place! We’ve put together a rundown of the most often requested Java interview questions to help you pass your Java career interview.

Java Interview Questions

Let us have a look at the major Java interview questions.

Question 1: What is Java?

Java is a general-purpose ,object-oriented and a high-level programming language.

Question 2: What is Java Virtual Machine?

JVM is a program that helps to interpret the intermediate Java byte code and generates the desired output.

Question 3: Explain the feature of Java platform independent?

Java JVM can covert the source code into corresponding byte codes these byte codes can be run on any OS independent of the platform.

Question 4: What is mean by singleton class in Java ?

The singleton class is the that can be create only one instance at any time in one JVM.

Question 5: What are access modifiers in Java?

Access modifiers in Java specifies the scope and visibility of Java variable.

The four Java access modifiers are

1. Default

2. Private

3. Protected

4. Public

Question 6: Why Java Strings are immutable in nature?

Java Strings are immutable which meaning that the value of Java string variable can’t be modified or unchanged. We can change the values only by specifying it by using a StringBuffer or StringBuilder.

Question 7: What is Request Dispatcher?

The Request Dispatcher is used to sending the request to another resource of the type html, servlet or jsp.

The methods of Request Dispatcher are

1.void forward()

2.void include()

Question 8: What is the life-cycle of a servlet?

1. Servlet is loaded

2. Servlet is instantiated

3. Servlet is initialized

4. Service the request

5. Servlet is destroyed

Question 9: Explain different methods of session management in servlets?

Common session management methods are

1. User Authentication

2. HTML Hidden Field

3. Cookies

4. URL Rewriting

5. Session Management API

Question 10: How to integrate Spring and Hibernate Frameworks?

Hibernate and Spring are Java frameworks they are integrated with help of DAOpattern and its dependency injection.

Question 11: Is it possible to restrict Inheritance in Java?

Yes, inheritance in Java can be restricted by using the following methods

1. By using the final keyword.

2. By making the methods as final.

3. By using private constructor in a class.

4. By using (//) Javadoc comment in a Java program

Question 13: What is the function of a constructor in a Java class?

Java class constructors are used to initialize the state of any object only after creating an object using the new keyword.

Question 14:What is the use of looping?

Loops in Java help the programmer to execute a part of program repeatedly in several times. Java have for , while and do-while as looping statements.

Question 15:How to perform Java Database Connectivity in a Java program?

The five major steps to achieve JDBC(Java Database Connectivity) are

1. Register the driver class

2. Create the connection

3. Create the statement

4. Execute the queries

5. Close the connection

Question 16:What Is the concept of Multi-Threading in Java?

Multi-threading is the process of executing multiple task simultaneously. In Java Multi-threading is achieved by using extending from Thread class or implementing from Runnable interface.

Question 17: What are Packages in Java?

Java packages are collection of classes and interfaces.

Question 18: What is the function of main method in Java?

Main() method is the entry point of all Java programs . The syntax of main is given below

public static void main(String args[])

{

}

Question 19: What is static keyword in Java?

static keyword in Java used to share the value between the objects and it is global in nature.

Question 20: What is the use of instanceof keyword in Java?

instanceof keyword is used to check whether the specified object is an instance of the particular class or not.

It is very important to take a training for Java to get a confidence to attend all interviews. Grooming for an interview would be equipped well when guided by professionals. So to learn more about Java it is always better to get in touch with the best Java training in Kochi or any other cities. There are various Java training institutes are readily available to assist you. The key point is finding the optimal Java online training in Kochi so that you can learn, grow and be experts in your field.