Home
Blog
Full Stack Development
Private Constructor in Java: Use Cases Explained with Example

Private Constructor in Java: Use Cases Explained with Example

Updated on 04 July, 2024

57.52K+ views

• 12 min read

Table of Contents

What is a Private Constructor?
What is the purpose of a Private Constructor in Java?
What are the Rules for Private Constructors?
What are the Use Cases of Private Constructor in Java?
Conclusion

In Java programming, understanding the intricacies of class design and object creation is crucial for developers aiming to excel in their careers. Among these intricacies, the concept of a Private Constructor in Java emerges as a fundamental aspect that piques the curiosity of many aspiring to master the language. Through years of coding and project development, I’ve come to value the nuances and advantages of using private constructors in Java applications. This introduction is your doorway to grasping the what, why, and how of private constructors.

From enhancing encapsulation to implementing singleton design patterns, private constructors offer unique advantages in Java. I aim to share insights from real-world applications, clarifying how private constructors can be employed to forge more secure and well-organized code. This article is intended for professionals seeking to expand their Java knowledge, encompassing key topics such as the definition of a private constructor, its governing rules, and its practical applications. We will conclude by highlighting the importance of private constructors in Java development, providing a thorough understanding of their role in creating robust and maintainable code.

Check out our free courses to get an edge over the competition.

Explore Our Software Development Free Courses

Fundamentals of Cloud Computing	JavaScript Basics from the scratch	Data Structures and Algorithms
Blockchain Technology	React for Beginners	Core Java Basics
Java	Node.js for Beginners	Advanced JavaScript

What is a Private Constructor?

In my journey as a software developer, I’ve often encountered scenarios where the concept of a Private Constructor in Java proved to be a game-changer. A private constructor is a particular type of constructor in Java designed to restrict the instantiation of a class from outside its own boundary. This means with a java class with private constructor, you cannot create an object of this class from any other class.

Why use it, you might ask? Throughout my career, I’ve leveraged private constructors in several use cases, such as creating utility classes where static methods and fields need not be associated with any particular object. For instance, consider a utility class that provides mathematical operations. By making its constructor private, we ensure that no one can create an example of this class, maintaining its purpose as a pure utility provider without any instantiation overhead. Using a private constructor, we enforce this uniqueness, preventing any other class from creating another instance.

What is the purpose of a Private Constructor in Java?

A private constructor in Java serves multiple essential purposes. Firstly, it restricts the instantiation of a class to within the class itself, preventing external code from creating instances directly. This is particularly useful for enforcing design patterns such as Singleton, where only one instance of a class should exist throughout the application’s lifecycle. By controlling object creation internally, private constructors ensure that the class adheres to specific initialization logic, maintaining consistency and integrity in its state.

Secondly, private constructors are utilized in utility classes that provide helper methods and constants but do not require instantiation. This approach promotes efficient and organized code structure by centralizing functionality without the overhead of object creation. Such classes often house static methods for tasks like mathematical computations, file operations, or configuration management, offering reusable functionalities without the need to instantiate objects. Overall, private constructors contribute significantly to encapsulation by confining object creation details within the class, thereby enhancing code reliability and promoting best practices in Java development.

What are the Rules for Private Constructors?

In my years of experience as a Java developer, I’ve encountered several scenarios where using a Private Constructor in Java was beneficial and essential. Let me share some rules and insights on this topic based on real-life applications and their impact.

Singleton Pattern Implementation: The most common use case for a “Private Constructor in Java” is in the Singleton design pattern. Here, ensuring that a class has only one instance requires that the constructor be private. This control mechanism prevents any other class from instantiating it directly.
Utility Classes: For classes that serve purely as collections of static methods and static variables, making the constructor private prevents instantiation. It’s a practical approach I’ve employed in numerous projects to signify that the class is a utility holder.
Factory Method Pattern: In scenarios where classes are designed with factory methods responsible for object creation, private constructors restrict instantiation to within the class itself. This technique ensures that object creation is controlled and can be modified without affecting external code.
Controlling Access: The private constructor in Java access rule is pivotal in controlling how other classes interact with the constructor. It effectively limits access to the constructor, thereby guiding the use of the class in a predefined manner. Understanding how to access private constructor in Java involves defining a public static method within the class that calls the private constructor, ensuring that object instantiation follows specific guidelines set by the class design.
Extending Classes: It’s worth noting that a class with a private constructor cannot be subclassed. This rule is particularly useful when creating immutable classes or ensuring that the integrity of the class hierarchy is maintained without unexpected subclassing.

Incorporating private constructors in Java, based on these rules, has significantly influenced the design and functionality of the applications I’ve worked on.

What are the Use Cases of Private Constructor in Java?

Private constructors in Java are accessed only from within the class. You cannot access a private constructor from any other class. If the object is yet not initialised, then you can write a public function to call the private instructor. If the object is already initialised, then you can only return the instance of that object. A private constructor in Java has the following use-cases:

You can use it with static members-only classes.
You can use it with static utility or constant classes.
You can use it to serve singleton classes.
You can use it to assign a name, for instance, creation by utilising factory methods.
You can use it to prevent subclassing.

Check Out upGrad Full Stack Development Bootcamp (JS/MERN)

Explore our Popular Software Engineering Courses

Master of Science in Computer Science from LJMU & IIITB	Caltech CTME Cybersecurity Certificate Program
Full Stack Development Bootcamp	PG Program in Blockchain
Executive PG Program in Full Stack Development
Software Engineering Courses

upGrad’s Exclusive Software and Tech Webinar for you –

SAAS Business – What is So Different?

Check Out upGrad Advanced Certification in DevOps

Singleton Class

The private constructor in Java is used to create a singleton class. A singleton class is a class in Java that limits the number of objects of the declared class to one. A private constructor in Java ensures that only one object is created at a time. It restricts the class instances within the declared class so that no class instance can be created outside the declared class. You can use the singleton class in networking and database connectivity concepts.

Here are some private constructor in java with examples:

Example 1: The following example demonstrates how a private constructor in Java limits the number of objects in a singleton class.

import java.io.*;
class newTestClass {
static newTestClass object = null;
public int a = 20;
private newTestClass() {
}
//we have created a private constructor
static public newTestClass displayInstance()
/**
*displayInstance() is a public method that we will use to create instance.
*Call this method to access these instances from outside the class.
*/
{
if (object == null)
     object = new newTestClass();
     //singleton class object is created
     return object;
}
}
public class SingletonClass {
public static void main(String args[]) {
     newTestClass instance1 = newTestClass.displayInstance();
     //displaying the instance of the singleton class by calling the public method
    newTestClass instance2 = newTestClass.displayInstance();
    //displaying the instance of the singleton class by calling the public method
    instance1.a = instance1.a + 26;
    System.out.println("Instance 1 created has the following value = " + instance1.a);
    System.out.println("Instance 2 created has the following value = " + instance2.a);
}
}

Output

Instance 1 created has the following value = 46

Instance 2 created has the following value = 46

In the above program, the value of instance 2 automatically gets updated when we update the instance1 object value. This observation demonstrates that both instance1 and instance 2 refer to the same object.

Our learners also read: Free java course!

Example 2: The following example demonstrates how a private constructor in Java ensures that no more than one object is created at a time.

// Java program for a singleton class implementation
Import java.io.*;
public class newTestClass {
   private static newTestClass var=null;
   private newTestClass(){
   //Private Constructor can be accessed within the class
   }
   public static newTestClass testObject(){
           // This method ensures that only one object is created at a time
           if(var==null){
           var= new newTestClass();
           }
     return var;
   }
   public void display(){
           System.out.println("This is an example of a Private constructor using a Singleton class. ");
   }
   public static void main(String args[]){
           newTestClass newObject= newTestClass.testObject();
           newObject.display();
   }
}

Output

This is an example of a Private constructor using a Singleton class.

In-Demand Software Development Skills

JavaScript Courses	Core Java Courses	Data Structures Courses
Node.js Courses	SQL Courses	Full stack development Courses
NFT Courses	DevOps Courses	Big Data Courses
React.js Courses	Cyber Security Courses	Cloud Computing Courses
Database Design Courses	Python Courses	Cryptocurrency Courses

Example 3: Private Constructor in Java to limit the number of class instances.

This example demonstrates how you can limit the number of class instances by declaring a constructor private.

public class restrictInstanceCreationClass {
           public static void main(String[] args) {
                          RestrictInstance obj;
                          int a=1;
                          while(a<=20)
                          {
                                        obj = RestrictInstance.getLimInstance();
                                        a++;
                          }
           }
}
class RestrictInstance {
           public static int varCount = 0;
           /**
           *create private constructor that increases the count
           *of varCount variable after each instance creation
           */
           private RestrictInstance() {
                          varCount++;
                          System.out.println("Instance number " + varCount + " is created.");
           }
           public static synchronised RestrictInstance getLimInstance() {
                          if(varCount <5) {
                                        return new RestrictInstance();
                          }
                          System.out.println("Maximum instance limit reached. You are not allowed to create anymore instances.");
                          System.gc();
                          return null;
           }
           /**
           *delete the instance and decrease the count
           *of the varCount variable
           */
           public void finalise()
           {
                          System.out.println("Instance is deleted.");
                          varCount--;
           }}

Output

Instance number 1 is created.

Instance number 2 is created.

Instance number 3 is created.

Instance number 4 is created.

Instance number 5 is created.

Maximum instance limit reached. You are not allowed to create anymore instances.

Instance is deleted.

Maximum instance limit reached. You are not allowed to create anymore instances.

Instance number 1 is created.

Instance number 2 is created.

Instance number 3 is created.

Instance number 4 is created.

Instance number 5 is created.

Maximum instance limit reached. You are not allowed to create anymore instances.

Instance is deleted.

Instance number 1 is created.

Instance number 2 is created.

Instance number 3 is created.

Instance number 4 is created.

Instance number 5 is created.

Learn Software Courses online from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs, or Masters Programs to fast-track your career.

Learn Java Tutorials

Java Tutorials	Java Classes and Objects	Java 8 features	Operators in Java
Static Keyword In Java	Switch Case In Java	Packages in Java	For Loop in Java
Thread Lifecycle In Java	OOP vs Functional vs Procedural	Instance variables in Java	Loops in Java
Identifiers in Java	Java Frameworks	String Comparison in Java	charAt() in Java
View All Java Tutorials

Conclusion

The code used in the article is only for explanatory purposes. You can modify the statements given in the examples as per your requirements. In this blog, I have discussed how a private constructor in Java limits the number of objects in a singleton class.

You can try out the code to strengthen your Java constructor’s knowledge. If you want to gain an in-depth understanding of Java, check out the upGrad Executive PG Program in Full Stack Development course that is designed for working professionals to gain expertise in this area.

Check out all the Trending Java Tutorial Topics in 2024.

Frequently Asked Questions (FAQs)

1. What are constructors in programming?

Constructors in programming are the methods that are called automatically when an object is initialized. The constructor's purpose is to initialize the object. Constructors should always be public and they are declared without any return type. Constructors are used to initialize the object and to perform other tasks that can be done only once. Constructors are also used to perform initialization of a class, that is, to perform tasks that create the class.

2. What are the types of constructors in Java?

There are five types of constructors in Java. They are: No-argument constructors: It has a default implementation, which is executed when the class is loaded into the memory. A class which has no no-argument constructor MUST be declared as final. Default constructors: This constructor is created when the class is written in Java and is used to initialize all the class's variables (attributes) to their default values (zero or null). Parameterized constructors: This constructor is used to initialize some variables from some values. Constructors with no return value: It is used to initialize some variables from some values. Constructors with return value: it is used to initialize some variables from some values and also returns with a value.

3. What is a private constructor in Java?

Private constructors can be used to create an immutable class. Without using private constructors, we can create immutable classes by declaring the class final and creating all the attributes as final (e.g. private final String name;). A private constructor cannot be directly called by client objects of the class. They can only be called internally by methods of the class (even private). You can have a private constructor with one or more parameters. You cannot have return type of the constructor be primitive boolean. It can be either String or Class.

4. What is public and private in constructor?

In Java, a public constructor allows any part of the program to create instances of a class freely, providing unrestricted access to object creation. Conversely, a private constructor restricts instance creation to within the class itself, used to control how and when objects are created, as seen in Singleton patterns or utility classes that should not be instantiated.

5. Can a class with private constructor be inherited in Java?

No, a class with a private constructor in Java cannot be inherited because the subclass cannot access the private constructor of its superclass, preventing it from calling the constructor to initialize the parent class.

6. When to use public vs private in Java?

In Java, use the public access modifier for methods and variables when you want them accessible from any other class or package, allowing widespread use and interaction. On the other hand, employ the private access modifier to restrict access to methods and variables within the same class only, enhancing encapsulation by hiding implementation details and ensuring controlled, secure access to class internals.

7. Can a constructor be private in C++?

Private constructor in C++ cannot be explicitly declared, unlike in some other languages like Java. However, you can achieve similar functionality by declaring a constructor as 'private' within the class declaration. This prevents external instantiation but allows controlled object creation through 'friend' functions or static member functions.

RELATED PROGRAMS

AWS Certified Solutions Architect - Associate Training (SAA-C03)

AWS | upGrad KnowledgeHut

AWS Certified Solutions Architect - Associate Training (SAA-C03)

Certification
32-Hr Training by Dustin Brimberry
Question Bank with 300+ Practice Qs

View Program

upGrad KnowledgeHut

Cloud Engineer Bootcamp

Bootcamp
6.5 Months
159+ Hours of Live Sessions

View Program

upGrad KnowledgeHut

Angular Training

Certification
13+ Hrs Instructor-Led Sessions
Live Doubt-Solving Sessions

View Program

SUGGESTED BLOGS

7.32K+

How to Become a Full Stack Developer: Part 1

It is the 21st century and the geek has inherited Earth. A Full Stack Developer has never been in greater demand. Under such circumstances, learning to build software is one of the most pragmatic things you could do to magnify your job prospects. The pay for a full stack developer is extremely competitive. Be it in tech giants (like Google, Amazon and Facebook) or internet companies (like Flipkart, Ola and PayTm) or even IT powerhouses (like Infosys, Accenture and Wipro); they are known to occupy the top spots in the lists of best companies to work for. In short, if you’re good at what you do, there will never be a shortage of jobs or money. But financial motivation aside, there are certain unassailable benefits attached to programming. For one, as Steve Jobs had stated, it teaches you how to think. A computer is a machine with Zero IQ. Telling it what to do to ensure it acts the way you want it to, under varying circumstances, will shoot up your reasoning and analytical skills by a non-trivial amount. Check out our free courses to get an edge over the competition. Motivation To me, the most potent benefit has to be power. Programming makes you feel powerful. It gives you the ability to create anything imaginable on a computer: Music Players, Social Networking Sites, Blogs, Search Engines, Workout Assistants; you name it and you can build it. Converting design mocks into real, working apps is a euphoria I wouldn’t trade anything in the world for. Once you’ve taught yourself to program, your imagination is the only thing stopping you from creating the next big thing. Some of the greatest minds explain why you should learn to program, no matter who you are: I’m going to tell you how to go about acquiring these full stack development skills. It doesn’t matter what your college major was or the field you’re currently working in. Neither does your age or your self-perceived intellectual capability matter. Contrary to what most people think, literally anybody can program. All you need is a computer and an internet connection. Check out upGrad’s Advanced Certification in Cyber Security That said, let’s begin our full stack journey! Step 1: Fundamentals of Computer Science Before you venture into full stack development or any of the various fields of computer science, it is imperative that you get your basics straight. Online education has been one of the biggest boons to the field of education and the art of self-learning. With the advent of universities putting up their courses online, there isn’t a dearth of quality content on any subject you could imagine yourself studying. Computer Science is no exception. I’d suggest signing up for Harvard University’s CS50: Introduction to Computer Science on edX. David Malan is one of the best instructors on the planet and his enthusiasm for the subject is sure to rub off on you by the time you’re done with the course. To give you a sort of a teaser as to what is in store, you will learn up to 5 programming languages and technologies (including C, Python and Javascript), build a stock exchange and trade stocks, build a version of Pong and program with Google Earth to take a virtual tour of Harvard’s campus, etc. Another option I’d suggest taking is the Pre-Course of IIIT-B & UpGrad PG Diploma program in Software Development. The entire program spans over 11 months, but I really like the way they have structured content to start off from the basics of computer science and then help you build your skillset when it comes to advanced concepts of full stack development. Explore our Popular Software Engineering Courses Master of Science in Computer Science from LJMU & IIITB Caltech CTME Cybersecurity Certificate Program Full Stack Development Bootcamp PG Program in Blockchain Executive PG Program in Full Stack Development View All our Courses Below Software Engineering Courses Check out upGrad’s Advanced Certification in Cloud Computing Once you’re done with them, you’ll have a pretty good idea as to what the field of Computer Science has to offer. From here, you can dive deeper into the many branches of CS: AI and Machine Learning, Data Science, Full Stack Development, Information Security, etc. In this series of posts, however, I will only be covering a suggested path towards teaching yourself Full Stack Development. Interview with Ankit Tomar, Co-Founder & CTO, Bizongo Step 2: Data Structures and Algorithms When you become a full stack developer, it is extremely important you understand how to store a particular piece of data and how to implement a certain task in the most efficient and logical way possible. This is where Data Structures and Algorithms come in. They are the lifeblood of every branch of Computer Science in existence. How does Google Maps calculate the shortest distance to our destination? What’s behind Netflix recommending movies? How does Facebook store and render the data of its billion-plus users? The answers lie in powerful data structures and algorithms. No wonder they are the topic of choice in almost every technical interview you will ever sit in. For this step, I’d recommend going through Princeton University’s Algorithms I & II. They are taught by Robert Sedgewick, a renowned Computer Science professor. For our purposes, these courses should suffice to give us a strong understanding of how logic and structuring work in Computer Science. However, if you’d prefer to go a little deeper into the subject, I’d suggest going through Stanford’s Design and Analysis of Algorithms series of courses. Keep in mind though that the course is considerably more mathematically intensive and lays immense emphasis on proofs. But should you be able to graduate, you can consider yourself an expert on the subject. Finally, any list of resources for Algorithms would be incomplete without CLRS. Titled Introduction to Algorithms, it is the bible on the subject of algorithms. Anything that you could possibly want to know is in this book. Again, like the Stanford courses, the book is mathematically heavy and language agnostic and for our purposes, optional. Explore Our Software Development Free Courses Fundamentals of Cloud Computing JavaScript Basics from the scratch Data Structures and Algorithms Blockchain Technology React for Beginners Core Java Basics Java Node.js for Beginners Advanced JavaScript Step 3: User Experience and Design The final ‘prerequisite’ before we delve into full-stack web development technologies is UI and UX. Now, unless you want to be a unicorn, you will not be designing apps yourself. Rather, you will be converting design mock-ups and product descriptions into code. Nevertheless, I believe that every developer must have a rudimentary knowledge of UX/UI principles and the world of design, in general. For this, I’m going to suggest two books which are of monumental importance to the world of full stack development. The first is Steve Krug’s Don’t Make Me Think. This book will teach you the basics of UX/UI and the ability to differentiate good design from bad. The other one, The Design of Everyday Things is a book almost every designer I know swears by. It is often called the bible of design and rightly so. You will find yourself looking at the world in an entirely different way after reading this book. These two books should be enough for our purposes. The book will arm you with tools that will let you identify good design(er)s from bad. It will also help you build decent looking websites without the help of a mockup from a professional. How to Become a Full Stack Developer: Part 2 Step 4: HTML and CSS HTML and CSS are the technologies that run every single website on the internet. The HTML provides the structure. The CSS provides style. If you’ve followed the path suggested so far, you may have already been introduced and gained a basic understanding of these technologies. HTML and CSS aren’t programming languages. Their syntax is incredibly simple to grasp. However, when used incorrectly, they can wreak all sorts of havoc. It is imperative you learn how to structure and style your websites well. UpGrad & IIIT-B’s Software Development program would be mighty helpful for those who wish to learn these technologies to create engaging and responsive user interfaces. Supplement the course by going through Head First’s HTML and CSS and HTML5 Programming. The latter book will help you familiarise yourself with the HTML5 standard. In parallel, I would suggest learning about Twitter’s Bootstrap library through scores of online material available on the subject. As you progress as a developer, you will gradually realise that CSS can be complicated. Bootstrap helps us alleviate a considerable amount of that pain and helps in making the website responsive and mobile friendly. That said, always keep a CSS Reference Guide close to you. I’d recommend CSS3: The Missing Manual by David McFarland. Also, create an account on StackOverflow if you haven’t already. A considerable amount of your stylesheet code is going to be copy-pasted from this God-sent website. In-Demand Software Development Skills JavaScript Courses Core Java Courses Data Structures Courses Node.js Courses SQL Courses Full stack development Courses NFT Courses DevOps Courses Big Data Courses React.js Courses Cyber Security Courses Cloud Computing Courses Database Design Courses Python Courses Cryptocurrency Courses Step 5: JS and jQuery You now know how to add structure and style to your web pages. Now, it is time to add responsiveness. Enter Javascript. Javascript, or JS, is the language of the web and the only language that every browser can parse. Its monopoly on the web makes it a mandatory skill for every full stack web developer. Even if you grow to hate it, you will have to put up with it and all its idiosyncrasies. A good place to start would be Head First’s Javascript Programming. The book provides a gentle introduction to the subject. Follow this up with Douglas Crockford’s Javascript: The Good Parts. This book will teach you to treat Javascript with the caution it deserves and the best practices while programming in it. Javascript is a tough language to master. Often, it is incredibly counterintuitive and annoying to deal with. To alleviate the world’s front-end developer’s pains, John Resig built the jQuery library. jQuery does things in a line where vanilla Javascript would have required a dozen. To maintain your sanity, it is absolutely essential that you get a strong grasp of jQuery. For this, go through Head First jQuery. To obtain mastery over the library, give jQuery: Novice to Ninja a thorough read. Congratulations! You are now a Front-end Developer. Theoretically speaking, you now have the tools to build the front-end of every website in existence. And I strongly suggest you do so in order to convince yourself of your newly found powers. Which brings me to the next step…s Step 6: Build a Website You now have the skills to build static websites. This is a good time to take on a few projects and build a website from scratch. There are many ways you could do this: If you’re in college, volunteer to build the website for a student group. Build your personal website. Put up samples of your work, social links, resume, articles, blog, etc. Apply for a freelancing job to build the frontend of a website. It can be anything, really. For instance, once I was done learning these technologies, I built a website for my college’s Dramatic Section. The website, in retrospect, was poorly structured and didn’t work on mobiles. But I learnt much more by doing that than from all the courses and books I’d gone through. Step 7: Front-end Javascript Frameworks With the advent of Single Page Applications, there has been a sudden surge in demand for front-end Javascript Frameworks. These frameworks aim at providing an MVC type of structuring on the front-end and delegate more and more backend tasks to the front-end. It is also incredibly useful in mocking the endpoints before the actual backend of the application is built. The usage of front-end frameworks like Angular and React has increased exponentially and almost every other startup uses it. So, I believe it is important you gain a rudimentary grasp of the major frontend frameworks. The most popular ones are Google’s Angular and Facebook’s React. The best place to get started with Angular would be the tutorial hosted on the official website. To gain mastery of the framework, go through Ng book 2. It’s highly recommended. As far as React is concerned, it is rapidly becoming the most popular frontend platform in the world, with a 300% rise in React developer jobs. UpGrad & IIIT-B’s Software Development program is a great platform for you to build expertise over this framework. Through the program, you would get valuable hands-on experience on React working on cool projects like creating an Instagram-lookalike or a Quora-like website on your own. Interview with Farooq Adam, Co-Founder, Fynd Conclusion So far, we’ve gone through curated lists to introduce ourselves to Computer Science, learn Data Structures and Algorithms, Design Principles and the technology stack of a front-end developer. In the next posts, I shall be covering the following: Back-end Development Mobile App Development I hope you’ve found this article useful. If there are resources or technologies I’ve left out that you feel are important, please do mention them in the comments!

by Rounak Banik

01 Dec'17

5.27K+

How to Become a Full-Stack Developer: Part 2

This is the second in a series of posts on teaching yourself programming and full-stack development. If you haven’t checked out the first part, on learning CS Fundamentals, Algorithms, Design Principles and Front-end Development, you can do so here. Check out our free courses to get an edge over the competition Motivation You now know how to build static websites using HTML, CSS, and Javascript. Although the Internet was originally designed to share static web pages, the capabilities (and expectations) of a modern web app have increased gigantically. Almost every app requires that you authenticate users, respond to them and replicate real-world scenarios as closely as possible. To do the aforementioned, you need to get data from a user (or an API), process it and produce an output. You also need to save this data and have a mechanism to identify the user the next time s/he returns to use your app. To perform these functions, our present stack isn’t enough. Interview with Ankit Tomar, Co-Founder & CTO, Bizongo Check out upGrad’s Advanced Certification in Blockchain Servers are required to process user data, store files, convert it into HTML/CSS/JS. Then, these servers serve it to the browser in a form that can be presented to the user. A database is required to store data important to your app. To program the server, we require a server-side scripting language and for the database, we require a database (duh) and a language to communicate with it. This is exactly what we’re going to do in the next steps. For the first seven, refer to the earlier post! Learn Software Development Courses online from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs or Masters Programs to fast-track your career. Step 8: Server Side Scripting Languages As mentioned before, to program and communicate with your server, you will need to know a language it understands. Unlike front-end where Javascript is the only choice, there are a plethora of options available for you to program on the backend. The most popular ones are Java, PHP, Python, JavaScript and Ruby. PHP has its shortcomings, but it has the gentlest learning curve out of all the languages and frameworks I’ve used so far. And PHP is about coding quick (and dirty) solutions. So, in an extremely short period of time, you can build a web app to be extremely proud of. Java is a general-purpose programming language and probably the most popular language of all time. It is extremely popular for building mobile apps (on the Android platform) and used extensively in most major tech companies. Head First Java is an excellent place to learn this ubiquitous language. Explore Our Software Development Free Courses Fundamentals of Cloud Computing JavaScript Basics from the scratch Data Structures and Algorithms Blockchain Technology React for Beginners Core Java Basics Java Node.js for Beginners Advanced JavaScript Check out upGrad’s Advanced Certification in DevOps To learn Python, I’d strongly recommend Zed Shaw’s Learn Python the Hard Way and Albert Sweigart’s Automate the Boring Stuff with Python. If you’ve decided to go with PHP, you can learn the basics of the language on Codecademy. You already know enough JavaScript syntax to get your hands dirty with the Node and backend JS frameworks (such as Express). I’ll cover Ruby later in conjunction with Rails as it is rarely used as a standalone language. Step 9: Learn SQL For the next step, you should probably pick up a little SQL (Structured Query Language). It is the language databases communicate with. And although you might not use it directly when you switch to using frameworks, it still helps to know how to directly communicate with your database. The good news is that SQL is incredibly easy to learn. You should be able to get a good grasp of it in a matter of hours. Head First SQL is a great resource for this purpose. How to Become a Full Stack Developer: Part 1 upGrad’s Exclusive Software Development Webinar for you – SAAS Business – What is So Different? document.createElement('video'); https://cdn.upgrad.com/blog/mausmi-ambastha.mp4 Step 10: Learn a ‘Conventional’ Full-Stack Web Framework Now is a good time to experiment with web frameworks that can do most of the lower level work for you. There isn’t a shortage of great frameworks that could cater to every purpose imaginable. Rails (written in Ruby), Spring (written in Java) and Django (written in Python) are among the popularly used frameworks today. You could take a look at Michael Hartl’s The Rails Tutorial – available for free. As far as Django is concerned, the tutorial on the official website is a good place to start. Once you feel you’re comfortable with the basics of the framework, do give Two Scoops of Django a read. It’s one of the best technology books ever. If you’ve decided to go the Spring route, I’d strongly suggest signing up for UpGrad & IIIT-B’s Software Development program. The program gives you a very holistic overview of the framework and helps you build a robust and scalable backend. Explore our Popular Software Engineering Courses Master of Science in Computer Science from LJMU & IIITB Caltech CTME Cybersecurity Certificate Program Full Stack Development Bootcamp PG Program in Blockchain Executive PG Program in Full Stack Development View All our Courses Below Software Engineering Courses Step 11: Javascript Full-Stack Frameworks and the MEAN Stack Not very long ago, Backend Development used to be based on the concept of the request-response cycle. For example, the browser sent a request and the server responded by spitting out a webpage in HTML. However, since early 2010, more and more applications have become real time. The structure of an entire web page changes without refreshing and behaves dynamically based on user input and interaction (Think chat, liking, commenting, live videos and reactions, etc.). In such a scenario, a simple request-response cycle simply isn’t enough. Therefore, there has been a recent surge of interest towards asynchronous programming and making AJAX requests the norm. Javascript Frameworks tend to excel at this. So, it makes sense to get acquainted with one of the major JS frameworks available in the market. The two most popular ones are the MEAN Stack and MeteorJS. Interview with Farooq Adam, Co-Founder, Fynd Learning MEAN is slightly more complicated due to its asynchronous nature and the callback hell Node usually tends to unleash. But now that you’re a seasoned developer, you are mature enough to deal with its idiosyncrasies. Meteor is a full-stack JS framework I’m currently experimenting with. The concept of Meteor is absolutely delightful – one framework in one language that takes care of all the components of an application (front-end, back-end, and database). However, this comes at the cost of customisation freedom. Once you’ve built something in Meteor, it is virtually impossible to change the database or the backend framework should you choose to do so. Though, I still think this is a worthwhile technology to learn. Meteor is known to be extremely powerful. It’s capable of doing things in hundreds of lines of code where other conventional frameworks would’ve required a thousand. In-Demand Software Development Skills JavaScript Courses Core Java Courses Data Structures Courses Node.js Courses SQL Courses Full stack development Courses NFT Courses DevOps Courses Big Data Courses React.js Courses Cyber Security Courses Cloud Computing Courses Database Design Courses Python Courses Cryptocurrency Courses Conclusion This is the end of part 2. In this post, we’ve covered resources concerning backend development and the various full-stack technologies available. You can now proudly call yourself a full-stack developer. Congratulations! But the story of full-stack web development doesn’t end here. With the introduction of the iPhone, there has been a smartphone revolution around the globe. More and more people are shifting towards using smartphones in place of desktops. In such a scenario, it is imperative that you learn to build apps for two of the most popular platforms out there: Android and iOS. We shall be covering this in the next and final part of this series. Additionally, we shall also look into frameworks that allow us to build native apps using Javascript (Ionic, React Native, etc.). Until then, it’s goodbye. 🙂 Your comments and suggestions are welcome! Read our Popular Articles related to Software Development Why Learn to Code? How Learn to Code? How to Install Specific Version of NPM Package? Types of Inheritance in C++ What Should You Know?

by Rounak Banik

01 Dec'17

5.3K+

How to Become a Full-Stack Developer: Part 3

This post is the third and final in the series on becoming a full-stack developer. This article talks specifically about mobile app development. Read here for more on frontend and backend development. When Steve Jobs introduced the iPhone in 2007, it ushered the biggest revolution the world had witnessed since the printing press. Smartphones have managed to penetrate almost every country on the globe. Even the most impoverished seem to be in possession of one so much so that life without them seems inconceivable. Check out our free courses to get an edge over the competition Motivation There are certain apps which make sense only when running on a phone. Take Uber, for instance. Uber needs to know your exact location through GPS. An Uber app for desktop wouldn’t make much sense. Another issue is that a majority of your audience will open your app through a phone, even if it is one that has been built for browsers. In such cases, it is imperative that you ensure the experience is seamless and too much data isn’t consumed. Finally, there are subtle differences between interacting using mouse-clicks and touch. Your app must ensure that it behaves well in both scenarios. Keeping all these considerations in mind, it makes good sense to venture out of the browser and build mobile apps. This ensures that you make maximum use of the functionalities a typical smartphone has to offer while at the same time making the user experience a delight. Below are the steps to acing mobile app development. For the first part to become a full stack developer on frontend and backend development. Check out upGrad’s Advanced Certification in Blockchain Learn Software Development Courses online from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs or Masters Programs to fast-track your career. Interview with Ankit Tomar, Co-Founder & CTO, Bizongo Step 12: Choose a Platform The first step would be to choose a platform where you would like to build your application. Unless you’re part of a reasonably big team, it is extremely unlikely that you will build apps from scratch on all major platforms. The more likely scenario is that you will be coding on your favourite platform and will then simply port it over to the others. The major smartphone platforms today are iOS, Android, and Windows. They use drastically different languages and IDEs. For instance, iOS uses Swift and XCode, Android uses Java and the Android Studio and Microsoft operate with C# and Visual Studio. upGrad’s Exclusive Software Development Webinar for you – SAAS Business – What is So Different? document.createElement('video'); https://cdn.upgrad.com/blog/mausmi-ambastha.mp4 Check out upGrad’s Advanced Certification in DevOps The market today is dominated by Android and iOS, so the choice really comes down to these two. Some things you may need to consider before making a choice is the audience share for your app. I believe it makes good business sense to build iOS apps if you’re in a First World country as Apple Devices are extremely popular there. In contrast, in a country like India, Android would be a more obvious choice as the market share for iPhones is extremely small owing to its exorbitant price. If you plan on making money from your app, keep in mind that iOS users are more likely to open their wallets for in-app purchases than their Android counterparts. This may be because iOS users usually tend to have more disposable income as compared to third world markets where Android dominates. iOS development requires you to have a Mac Development machine. Also, Apple App Store licenses retail at $99/year compared to Google Play’s one time $25 fee. In other words, iOS development is considerably more expensive. In this post, I shall cover how mobile app development is done today: Native Android Apps, Native iOS Apps and Hybrid Mobile Apps. Explore Our Software Development Free Courses Fundamentals of Cloud Computing JavaScript Basics from the scratch Data Structures and Algorithms Blockchain Technology React for Beginners Core Java Basics Java Node.js for Beginners Advanced JavaScript Step 13: Java and XML Java is the most popular language for Android Development (Google has recently introduced support for the Kotlin Programming language too). The founders of Android thought Java to be an appropriate choice and they have stuck to it since its inception. And if their trajectory is anything to go by, it has been nothing short of an amazing decision. The best resource to learn Java would be Head First Java. Reading this book will give you a thorough introduction to the language as well as Object Oriented Programming Principles. As far as XML is concerned, I do not think you need a concentrated tutorial on the subject. You’ve already worked extensively with a subset of XML (HTML) and you will be able to figure it out pretty quickly, even if you were to jump directly into Android development. I cannot say the same for Java. Ensure you have a good grasp of the language before venturing into Android. Step 14: Android You now have the technical know-how to build Android apps. It is time to dive deep into this revolutionary OS. Be wary though that certain Android practices differ from what you usually see on the web. The resources I’ve suggested below will ensure that your learning is not hindered by these differences. Android Programming- The Big Nerd Ranch Guide 2nd Edition is a good place to start if you know Java already. Make sure you pick up the second edition as that is the one that uses Android Studio, which is the industry standard now. The practice of building apps in Eclipse is largely outdated. Interview with Farooq Adam, Co-Founder, Fynd Explore our Popular Software Engineering Courses Master of Science in Computer Science from LJMU & IIITB Caltech CTME Cybersecurity Certificate Program Full Stack Development Bootcamp PG Program in Blockchain Executive PG Program in Full Stack Development View All our Courses Below Software Engineering Courses Step 15: iOS If you are more of an Apple aficionado and/or have decided that iOS apps make more sense to your business/career aspirations. The first step would be to acquire a Mac. XCode works only on Mac and in order to publish on the app store, you need a Mac. Sorry, VMWare. The resource I’m going to suggest for iOS is exactly the same as that for Android. Nerd Ranch has its own publication – iOS Programming: The Big Nerd Ranch Guide which deals with Swift and XCode, so that is a good place to start. Step 16: Hybrid Mobile Apps If you’re a solo developer or are working in a small team, you probably do not have the time or the resources to separately build and maintain Android and iOS Apps. To alleviate the developer’s pain of building for multiple platforms, the concept of Hybrid Mobile Apps was introduced. The concept is extremely simple and revolutionary. If you know Javascript, you already know how to build web apps. Therefore, should you have an app in JS, there must exist a framework that automatically ports your application into Android, iOS, and Windows. Incredible but true. Most hybrid frameworks achieve this using Cordova or React Native. You can think of Cordova as the bridge between browsers and the smartphone’s native hardware. It establishes a connection between the two solely using JS and helps in creating the build scripts in the native languages of each platform. Cordova based frameworks, however, are rapidly being overshadowed by Facebook’s powerhouse, React Native. The power of React Native lies in the fact that while Cordova constructs WebViews, React Native lets you build native apps that you’d build using either Java (for Android) or Swift (for iOS). In other words, Cordova is a website disguised as a mobile app, but React Native lets you build the real thing. In-Demand Software Development Skills JavaScript Courses Core Java Courses Data Structures Courses Node.js Courses SQL Courses Full stack development Courses NFT Courses DevOps Courses Big Data Courses React.js Courses Cyber Security Courses Cloud Computing Courses Database Design Courses Python Courses Cryptocurrency Courses In my opinion, you can give Cordova a miss and learn React Native instead. It is an extremely great career investment to make. UpGrad & IIIT-B’s Software Development program is a great place to start your journey with this revolutionary library which has already been used by companies like Facebook, Netflix and AirBnB to design their apps. Interview with Farooq Adam, Co-Founder, Fynd Conclusion With the conclusion of hybrid apps, we come to an end of this series. In summary, these are the things we’ve covered: Computer Science Fundamentals. Data Structures and Algorithms UI/UX HTML, CSS, JS Front-End Frameworks Server-Side Scripting and Databases Full Stack Frameworks Android and iOS Hybrid Mobile Apps Read our Popular Articles related to Software Development Why Learn to Code? How Learn to Code? How to Install Specific Version of NPM Package? Types of Inheritance in C++ What Should You Know? I hope you’ve enjoyed reading this series as much as I have enjoyed writing it and more importantly, found at least some parts useful. As always, your comments and suggestions are welcome!

by Rounak Banik

01 Dec'17

7.11K+

Why Companies are Looking to Hire Full Stack Developers

It’s no secret that companies today are looking to hire young and talented software developers. But with so many smart developers out there, how can you set yourself apart from everyone else applying for these coveted roles? The best way to do this is to master the skills companies demand: a wide variety of programming skills. When you are learning how to develop software, you can improve your odds of getting a job by learning full stack development. In fact, Indeed ranked the Full Stack Developer role as the #1 job in 2017. Check out our free courses to get an edge over the competition. There are three main reasons why companies love to hire young full stack developers: Full stack developers can solve many problems Companies look to hire people based on what problems the candidates can solve for the company. By definition, full stack developers can work on both backend, frontend, and the protocols that connect the two; being able to create a software product end to end and independently. When you learn full stack development, you have an advantage over other job seekers as you can solve many more problems than other developers. For example, think about working at a high growth startup. Startups need developers who can work on a variety of programming projects. From user interfaces to server-side programming, to database applications, and everything in between. With only a small team, startups want to hire full stack developers who can work on many of the different software projects. As a full stack developer, you build many types of software projects that most other developers cannot. Check out upGrad’s Full Stack Development Bootcamp (JS/MERN) Even at a larger company, hiring developers with the knowledge to work on many different projects gives a manager flexibility to move people between teams as businesses constantly need change. One year, you can have a developer work on a frontend project and then you can move him to a backend project the very next year. The added flexibility makes the manager’s job much easier so they like to work with developers with a wide variety of skills. Check out upGrad’s Java Bootcamp. How to Become a Full Stack Developer Companies love full stack developers because they can solve many different problems for the business. Companies like to hire young developers who are generalists The main reason is that companies hire young developers based on their potential rather than deep domain knowledge. Companies like to teach young developers what they want them to know. As a full stack developer, you have a broad set of technology skills that the company can help you expand further. As an entry-level developer, they don’t need you to understand every algorithm. But you need to have core programming knowledge so the company can teach you what is specific to their business. Let’s go back to the example of working at a startup. When the company is starting out, they need full stack developers to work on all layers of the development stack, but as the company grows, the developers will need to specialise. It’s easy for a full stack developer to start as a generalist and then become a specialist later as the company can hire more employees. On the other hand, it’s very difficult for a specialist to join a startup and learn to be a generalist when the company is small. Full stack developers can grow with their companies more easily than specialists can. In-Demand Software Development Skills JavaScript Courses Core Java Courses Data Structures Courses Node.js Courses SQL Courses Full stack development Courses NFT Courses DevOps Courses Big Data Courses React.js Courses Cyber Security Courses Cloud Computing Courses Database Design Courses Python Courses Cryptocurrency Courses Once you know the basics and get the job, the company will invest time and money to help you expand your knowledge further. Full stack developers can become great managers and executives Companies love to promote people with a wide variety of experiences in the business. As a full stack developer, you will get a chance to work on frontend software, backend software, and all of the architecture that connects them. Through that variety of experience on different projects, you get the opportunity to learn much more than your solely backend and frontend peers. They only get a chance to learn one part of the company’s technology architecture, but you learn the whole architecture and understand how it all fits together. That puts you in a great opportunity to rise through the technology ranks of the company and get promoted. If you work at a startup, your experience as a full stack developer can help set you apart from your peers as the company grows. Where some developers only know how one part of the technology stack works, you understand how all aspects of the technology fit together. As more developers are hired and new technology teams form, you are more likely to manage those new teams because of your wide knowledge. At a large company, you may also get more chances for promotion. When companies look to promote from within, they need people who can manage cross-functional software teams. As a full stack developer, you will know how to talk to developers from both frontend and backend teams. How to Succeed in Your First Software Development Job Of course, technology skills are not the only ones needed to get you a promotion. You will also need to learn business skills to be a manager. But if you do that you can climb high up the corporate ladder. Looking to become a full stack developer? This article does a great job explaining how to get started: How to become a full stack developer. Explore Our Software Development Free Courses Fundamentals of Cloud Computing JavaScript Basics from the scratch Data Structures and Algorithms Blockchain Technology React for Beginners Core Java Basics Java Node.js for Beginners Advanced JavaScript Enroll in Software Engineering Courses from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs, or Masters Programs to fast-track your career.

by Gopi Vajravelu

31 Jan'18

5.53K+

What is Test-driven Development: A Newbie’s Guide

Programmers and bugs have been in a never-ending fight for supremacy since time unknown. It’s unavoidable – even the best programmers fall prey to bugs. No code is truly safe from bugs, that’s why we perform testing. Programmers, at least the sane ones, test their code by running it on development machines to make sure it does what it was meant to do. Traditionally, test cases were written after writing the code, but in Test-driven Development, an automated test case is written before writing any piece of code so that the execution and testing can be checked simultaneously. In this article, we’ll be talking about Test-Driven Development in depth and why is it better than the traditional methods! Check out our free courses to get an edge over the competition What is Test-Driven Development? Test-Driven Development was created as part of the Extreme Programming (XP) methodology and was called the ‘Test-First’ concept. Test-driven development allows you to test your code thoroughly, and also enables you to retest your code quickly and easily since it’s automated. In essence, before writing any piece of code, the programmer first creates a unit-test. Then, the programmer creates just enough code to satisfy the unit-test. Once the test is passed and the code refactored, the programmer can go ahead with making further improvements. Test-driven development makes sure that the code is thoroughly tested which leads to a modularized, extensible, and flexible code. Each time a new feature is to be added, it needs to undergo what is called the “lifecycle” of TDD. Let’s talk more about this lifecycle. Check out upGrad’s Advanced Certification in DevOps How to Become a Full Stack Developer Explore Our Software Development Free Courses Fundamentals of Cloud Computing JavaScript Basics from the scratch Data Structures and Algorithms Blockchain Technology React for Beginners Core Java Basics Java Node.js for Beginners Advanced JavaScript Test-Driven Development Lifecycle The test-driven development lifecycle covers everything from writing the initial unit-test to reworking the code. Add a test: Every new feature needs to undergo a test before its implemented. The essential requirement for writing a test is to have a clear understanding of all the requirements. This is accomplished using use-cases and user-stories. Run all tests and check the net test: This is done to ensure the correct working of our test. Basically, this phase aims to check that the test is not passed by any code that doesn’t meet the requirements. By doing so, this step eliminates the possibility of having a faulty test at hand. Write code: Now that you have your test in place, the next obvious step is to write a code that clears the test. This code need not be perfect in all aspects, but it needs to clear the test. Once we’re sure this code clears the test, it can be modified as per the requirements. Run the tests: Having written the code, now it’s time to see if the code passes the test or not. If your code passes the tests, it means that your code meets the requirements – till now. Refactor the code: This is essentially done to clean up the code. Refactoring doesn’t cause damage to any of the functionalities; it is just for cleaning the code by removing duplication between test code and production code. Repeat: This cycle is now repeated with a fresh test to add more functionalities. Each functionality undergoes the same cycle. Essentially, the size of steps should be not more than 1-10 edits between each test run. If a code doesn’t pass the test rapidly, the developer must revert and not debug excessively. Check out upGrad’s Full Stack Development Bootcamp (JS/MERN) Why Companies are Looking to Hire Full Stack Developers Explore our Popular Software Engineering Courses Master of Science in Computer Science from LJMU & IIITB Caltech CTME Cybersecurity Certificate Program Full Stack Development Bootcamp PG Program in Blockchain Executive PG Program in Full Stack Development View All our Courses Below Software Engineering Courses The Pros and Cons of Test-Driven Development Test-driven development has some definite pros over traditional methods of testing – which were mostly manual. However, it’s not infallible. Just like any other technology, the test-driven development also has a set of cons. Let’s have a look at what are the benefits of TDD in detail: Writing small tests ensures modularity of your code. Practicing TDD helps you understand the underlying principles of good modular design. TDD provides clarity during the implementation of your code which enables a safety-net during the refactoring phase. With TDD, collaborating is a lot easier as now people can edit the code with confidence because the test will inform them if their changes are not up to the mark of the test. The base of TDD is unit-tests. Because of that, refactoring is a whole lot easier and faster. Refactoring an old code is a pain, but if the code is backed by unit tests, it becomes so much easier. It helps in clarifying all the requirements before you begin the coding part. This way, a lot of ambiguity that can arise later on is avoided. Test-driven development focuses on testing while writing. This forces the programmer to make their interfaces clean enough to pass the test. It’s hard to understand this advantage until you work on a piece of code that hasn’t undergone TDD. Silly mistakes are caught almost immediately. It helps in removal of those mistakes that would waste a lot of time if found in QA. In-Demand Software Development Skills JavaScript Courses Core Java Courses Data Structures Courses Node.js Courses SQL Courses Full stack development Courses NFT Courses DevOps Courses Big Data Courses React.js Courses Cyber Security Courses Cloud Computing Courses Database Design Courses Python Courses Cryptocurrency Courses Now, let’s have a look at what are the limitations of test-driven development: The test suite that’s used for testing needs to be maintained else the tests may not be fully deterministic. The tests are hard to write – especially beyond the unit-testing phase. TDD does slow down the pace of development, at least initially. Like with any form of development, there’s a big difference between just doing it and doing it well. Writing good unit tests requires a level of specialty. It’s difficult to apply this approach to your legacy(existing) code. TDD requires you to perform routine housekeeping. It’s necessary to refine the tests to make them run more quickly. It’s easy to get distracted by the fancy features in any unit-testing framework, but it should be kept in mind that simple tests tend to give the best results. Unless everyone on the team correctly maintains their tests, the whole system can quickly degrade. How to Succeed in Your First Software Development Job Read our Popular Articles related to Software Development Why Learn to Code? How Learn to Code? How to Install Specific Version of NPM Package? Types of Inheritance in C++ What Should You Know? In Conclusion… Test-driven development is the way forward as far as future of application development goes. There are a number of automated testing frameworks like PHPUnit, Serenity, Robot, RedWoodHQ, and many more. Pick the one that fits your need and get started with building better maintainable applications in no time! Enroll in Software Engineering Courses from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs, or Masters Programs to fast-track your career.

by Arjun Mathur

12 Mar'18

35.67K+

A Beginner’s Guide to MVC Architecture in Java

If you’re related to web development scene, you’ll most certainly have come across the acronym “MVC” hundreds of time, if not more. MVC is one of the most talked about design patterns in the web programming world today, and rightly so. In this article, we’ll take you through the world of MVC Architecture. We’ll talk about the basics of MVC, its advantages, and finally, a simple code that will help you understand the implementation of MVC in Java in a clearer way. What exactly is the MVC architecture? Before we get into the technicalities of it, let’s make some things clear – MVC is NOT a design pattern, it’s a way to structure your applications. In recent years, the web applications are extensively using the MVC architecture, and hence it’s natural to confuse it for a design pattern exclusive for web applications. However, let’s tell you that MVC was first described way back in 1979 – before the WWW era when there was no concept of web applications. The architecture used today for web applications is an adaptation of the original pattern. In fact, this architecture was initially included in the two major web development frameworks – Struts and Ruby on Rails. These two environments paved the way for a majority of web frameworks that came later – and thus the popularity of this architecture kept rising. Learn to build applications like Swiggy, Quora, IMDB and more MVC architectural pattern follows an elementary idea – we must separate the responsibilities in any application on the following basis: Model: Handles data and business logic. View: Presents the data to the user whenever asked for. Controller: Entertains user requests and fetch necessary resources. Each of the components has a demarcated set of tasks which ensures smooth functioning of the entire application along with complete modularity. Let us have a look at each of these components in further detail. Check out our free courses to get an edge over the competition. Explore Our Software Development Free Courses Fundamentals of Cloud Computing JavaScript Basics from the scratch Data Structures and Algorithms Blockchain Technology React for Beginners Core Java Basics Java Node.js for Beginners Advanced JavaScript upGrad’s Exclusive Software and Tech Webinar for you – SAAS Business – What is So Different? document.createElement('video'); https://cdn.upgrad.com/blog/mausmi-ambastha.mp4 Controller The controller is the like the housekeeper of the application – it performs coordination between model and view to entertain a user request. The user requests are received as HTTP get or post request – for example, when the user clicks on any GUI elements to perform any action. The primary function of a controller is to call and coordinate with the model to fetch any necessary resources required to act. Usually, on receiving a user request, the controller calls the appropriate model for the task at hand. Check out upGrad’s Full Stack Development Bootcamp (JS/MERN) Model The model is quite simply the data for our application. The data is “modelled” in a way it’s easy to store, retrieve, and edit. The model is how we apply rules to our data, which eventually represents the concepts our application manages. For any software application, everything is modelled as data that can be handled easily. What is a user, a book, or a message for an app? Nothing really, only data that must be processed according to specific rules. Like, the date must not be higher than the current date, the email must be in the correct format, the name mustn’t be more than “x” characters long, etc. Check out upGrad’s Java Bootcamp Whenever a user makes any request from the controller, it contacts the appropriate model which returns a data representation of whatever the user requested. This model will be the same for a particular work, irrespective of how we wish to display it to the user. That is why we can choose any available view to render the model data. Additionally, a model also contains the logic to update the relevant controller whenever there is any change in the model’s data. Explore our Popular Software Engineering Courses Master of Science in Computer Science from LJMU & IIITB Caltech CTME Cybersecurity Certificate Program Full Stack Development Bootcamp PG Program in Blockchain Executive PG Program in Full Stack Development View All our Courses Below Software Engineering Courses View As the name suggests, the view is responsible for rendering the data received from the model. There may be pre-designed templates where you can fit the data, and there may even be several different views per model depending on the requirements. Any web application is structured keeping these three core components in mind. There may be a primary controller that is responsible for receiving all the requests and calling the specific controller for specific actions. Let’s understand the working of a web application under the MVC architecture better using an example. Let’s See an Example Let’s take an example of an online stationery shop. The user can view items, buy, add items to cart, add items to current order, or even add/remove items (if he’s the admin). Now, let’s see what will happen when a user clicks on the title “Pens” to see the list of pens. Our application will have a particular controller to handle all the queries related to pens. Let’s say it’s called “pens_controller.php”. We’ll also have a model that will store the data regarding the pens we have – let’s call it “pens_model.php”. Finally, we’ll have several views to present the data – a list of pens, a table displaying pens, a page to edit the list, etc. The following figure shows the complete flow of control right from the moment a user clicks on “pens”, to when the result is rendered in front of him: First, the “pens_controller.php” handles the user request (1) as a GET or POST request. We can also have an “index.php” which is the central controller which will call the “pens_controller” whenever needed. The controller then examines the request and the parameters and calls the required model – in this case, “pens_model.php”. The controller asks the model to return the list of available pens (2). Now, the model searches the database for the necessary information (3), applies logics if necessary, and returns the data to the controller(4). The controller then picks an appropriate view (5) and presents the data (6 and 7). If a request comes from a handheld device, a view suitable for it will be used, or if the user has a particular theme selected, its view will be picked – and so on. How to Become a Full Stack Developer The Advantages of the MVC Architecture A common problem faced by application developers these days is the support for different type of devices. The MVC architecture solves this problem as developers can create different interfaces for different devices, and based on from which device the request is made, the controller will select an appropriate view. The model sends the same data irrespective of the device being used, which ensures a complete consistency across all devices. The MVC separation beautifully isolates the view from the business logic. It also reduces complexities in designing large application by keeping the code and workflow structured. This makes the overall code much easier to maintain, test, debug, and reuse. In-Demand Software Development Skills JavaScript Courses Core Java Courses Data Structures Courses Node.js Courses SQL Courses Full stack development Courses NFT Courses DevOps Courses Big Data Courses React.js Courses Cyber Security Courses Cloud Computing Courses Database Design Courses Python Courses Cryptocurrency Courses A Simple Implementation of MVC using Java We will have the following three: StudentObject : the model. StudentView: view class to print details on the console. StudentController: a controller that stores data in studentObject and updates StudentView accordingly Step 1: Create the Model public class Student { private String rollNo; private String name; public String getRollNo() { return rollNo; } public void setRollNo(String rollNo) { this.rollNo = rollNo; } public String getName() { return name; } public void setName(String name) { this.name = name; } } The code is self-explanatory. It consists of functions to get/set roll number and names of the students. Let’s call it “student.java”. Step 2: Create the View public class StudentView { public void printStudentDetails(String studentName, String studentRollNo){ System.out.println("Student: "); System.out.println("Name: " + studentName); System.out.println("Roll No: " + studentRollNo); } } This is simply to print the values to the console. Let’s call this “studentView.java”. Step 3: Create the Controller public class StudentController { private Student model; private StudentView view; public StudentController(Student model, StudentView view){ this.model = model; this.view = view; } public void setStudentName(String name){ model.setName(name); } public String getStudentName(){ return model.getName(); } public void setStudentRollNo(String rollNo){ model.setRollNo(rollNo); } public String getStudentRollNo(){ return model.getRollNo(); } public void updateView(){ view.printStudentDetails(model.getName(), model.getRollNo()); } } Call this “StudentController.java”. A cursory glance will tell you that this controller is just responsible for calling the model to get/set the data, and then updating the view. Now, let’s have a look at how all of this is tied together. Step 4: Create the main Java file public class MVCPatternDemo { public static void main(String[] args) { //fetch student record based on his roll no from the database Student model = retriveStudentFromDatabase(); //Create a view : to write student details on console StudentView view = new StudentView(); StudentController controller = new StudentController(model, view); controller.updateView(); //update model data controller.setStudentName("John"); controller.updateView(); } private static Student retriveStudentFromDatabase(){ Student student = new Student(); student.setName("Robert"); student.setRollNo("10"); return student; } } This is called “MVCPatternDemo.java”. As you can see, it fetches the student data from the database or a function (in this case we’re using a function to set the values) and pushes it on to the Student model. Then, it initialises the view we had created earlier. Further, it also initialises our controller and binds it to the model and the view. The updateView() method is a part of the controller which updates the student details on the console. Step 5: Test the Result If everything goes right, the result should be: Student: Name: Robert Roll No: 10 Student: Name: John Roll No: 10 If you get this as the output, congratulations! You’ve successfully implemented the MVC architecture using Java, albeit for a simple application. However simple, this application is enough to demonstrate the powers of the MVC architecture. 15 Must-Know Spring MVC Interview Questions Wrapping Up… After so much said and done, it’s hard to emphasise more on the power of the MVC architecture in any web/desktop application these days. It provides an altogether new level of modularity to your code which makes it a lot more readable and maintainable. So, if you want to scale to new heights in your career as an application developer, getting hold of the MVC architecture and its working should be your top priority. Read our Popular Articles related to Software Development Why Learn to Code? How Learn to Code? How to Install Specific Version of NPM Package? Types of Inheritance in C++ What Should You Know? Enroll in Software Engineering Courses from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs, or Masters Programs to fast-track your career. Do drop by a comment and let us know how you like this article!

by Arjun Mathur

09 Apr'18