How to get ready for Interviews on Java?

Today, most of the engineering students want to land in a software job with good pay package. But, as many as 90% of them fail in the technical interview in the interview round. The reason is simple – most of the students are missing the basics of technology as they are not serious about their academic activity during their course.

However, one can overcome the deficiency by understanding and working upon the basic of any technology. This article presents you the fundamental concepts of Java and useful for the candidates who wish to attend the interviews on Java.

These days, e-Commerce occupies a major role in our daily activities. Online Shopping, Online movie tickets booking, Internet bank transactions are quite useful and make our lives easy. All these applications need to develop in one of the computer programming languages.

The well-known computer programming languages are C, C++, .Net and Java. Most of the technical students (Information Technology/Computer Science Engineering and MCA) have Java programming language as one of their curriculum subjects. Students of other streams, do short term course on Core and Advanced Java for job trials.

If you want to become a good web developer/programmer in Java, first you need to understand three aspects of it thoroughly -

What Java is? Why it is there? and What are its features?

What to Learn?
As a fresh graduate, one should have strong knowledge in Basics of Java to work in its related projects.
Java is a platform independent language; i.e. can be developed in one environment/platform and can be run/execute on any other platform. For example, Java code can be developed in Windows and can be executed in Linux.

We need to learn “How Java is platform independent, what is the process of compilation and interpretation in Java.”

Since Java is an object oriented programming language (popularly known as - OOP), first we need to learn “What is Object Oriented Programming and definition of Object Orientation”.

Object-Oriented Programming (OOP) uses a different set of programming languages than old procedural programming languages such as C and Pascal. Everything in OOP is grouped as self-sustainable "objects". Hence, you can reuse those objects with the aid of four important object-oriented programming concepts.

The programming concepts are -

1. Encapsulation
2. Abstraction
3. Inheritance
4. Polymorphism.

The Basic structure of Java starts with ‘Class’ and we need to create ‘Object(s)’ for each Class to use/access its methods.

As part of this, we will learn what is the relation between the ‘Class’ and the ‘Object’.

Encapsulation & Abstraction
As part of these concepts, you will learn -

1. About the relation between Class and Object,
2. About access modifiers in Java (Public, Private, Protected and Default) and their access levels.
3. About interface and its usage.
4. About specific keywords like Static, final, abstract and many more.

Inheritance
As part of Inheritance, you will learn -

1. About what is inheritance
2. Super Class and Subclass and relation between them
3. The use of ‘super’ keyword
4. How to access super class methods in subclass etc.…

Polymorphism
As part of this concept, you will learn about -

1. Polymorphism, and
2. Overloading and Overriding.

By now you can understand why Java called as object oriented programming language or OOP.

The other important topics of the Java language include - Exception Handling, Multi Threading, I/O Streams and *Collections.

Exception Handling
This topic deals with -

1. What is an exception means?
2. How exception is different from error.
3. The different kinds of exceptions in Java
4. How we will handle exceptions in Java.
5. Different key words like finally, throw, throws, try, catch…etc.
6. What is difference between finally and final.

Multi Threading
Multi-Threading deals with -

1. What is a thread in Java?
2. Difference between Thread and Task.
3. Difference between Multi-threading and Multi-tasking.
4. Different states of Thread (i.e. start, stop, pause, run etc)
5. Joining of threads and how app performance improved using threads.

I/O Streams
As part of the I/O Streams, you will learn about -

1. How to read/write data from a file to other.
2. Input/output streams.
3. Readers and writers.

*Collections
This is a very important concept to learn about the package (Java.util.*), which provides different pre-defined classes and interfaces to reuse in Java. We use those classes/interfaces in our regular projects quite often.

1. Java.util package : Different classes and interfaces.

*JDBC:
JDBC is one more important concept where we will connect to Database and do different operations through Java program by using some pre-existing classes/interfaces.
Here, you shall understand -

1. What JDBC (Java Data Base Connectivity) is?
2. The concepts of Connection, Statement, Resultset, Prepared Statement and Callable statement, and
3. Execution of stored procedure(s) using JDBC.

By focusing on the aforetasted topics, you will gain enough knowledge to get through the written test and technical interview round. Wish you all the best!

 

Published date : 19 Nov 2013 03:37PM