Wednesday, March 27, 2019

How to Crack Spring Core Professional v5.0 Certification - Latest Spring Certification for Java Programmers

Ever since Pivotal, the company behind Spring framework made the mandatory Spring training optional (see here), I have received many queries from experienced Java developers who are interested in doing Spring certifications. This move from Pivotal has suddenly made the Spring certification affordable for many experienced Java and Spring developers who were interested in Spring certification earlier but couldn't progress further due to expensive mandatory training. Since many of them are now preparing for Spring certifications e.g Spring Core 5 or Spring Professional 5 via self-study they are increasingly looking for good resources to prepare for the exam. I have received a lot of questions on preparation, books, mock exams, exam structure, passing marks and useful resources.

The 2019 DevOps Developer RoadMap - Your Guide to become DevOps Engineer

DevOps is really hot at the moment and most of my friends, colleagues and senior developers I know are working hard to become a DevOps engineer and project themselves as DevOps champion in their organization. While I truly understand the benefit of DevOps, which is directly linked to improved software development and deployment, from my limited experience I can say that it's not an easy job. It's very difficult to choose the right path in mind of so many tools and practices. Many of my readers also ask me this question is how to become a DevOps engineer, which tools should I learn? which practices should I follow? does learning Maven and Jenkins must for a DevOps guy? how about Docker and Kubernetes? Does infrastructure automation part of DevOps? should I learn Chef, Puppet, or Ansible are just some of those questions which keep coming to me.

Tuesday, March 26, 2019

Top 9 Java Programming Books - Best of lot, Must Read

These top Java programming books are some of the good books to learn Java and I would say some of them are simply best Java books ever published. Whenever a programmer starts learning Java programming language, the first question he asks is "Which book should I refer to learn Java?", or "What is the best book to learn Java for beginners?" or "Can you tell me some good books to learn Java?" .That itself says how important Java books are for programmers especially beginners.  Despite having so many free resources available in Java like tutorials, tips, blogs and code examples, Java books have their own place because of two reasons:
  • They are written by programmers who are authority in subject
  • They cover the subject with more details and explanation.

Java 8 Certifications - Oracle Java SE 8 Programmer 1 (1Z0-808) - Latest OCAJP Exam (OCP 11 1Z0-815 and 1Z0-816)

Update: The latest version of Java SE certification is now OCAJP 11 (1Z0-815) and OCPJP 11 (1Z0-816) which is based upon Java 11 version. You can take these two exams to become a certified Java 11 developer, but if you already have an Oracle Certified Professional Java Programmer for the Java 6, 7, or 8 version, then you can take the upgrade OCP Java 6, 7, and 8 to Java SE 11 Developer exam (Exam Code 1Z0-817). I don't have much detail so I still keep this post as it is but once I have got more information. I will also update this post. Today one of my readers asked about what is the latest OCPJP or SCJP exams available and is there a Java certification available for Java SE 9 and Java SE 10? This prompted me to browse through Oracle's certification website. During my casual browsing, I noticed that even though it's almost a year since Java SE 9 was released and 6 months since Java SE 10 was released the latest Java certification is still the Java  SE 8 certification. I know, you might be thinking about Java SE 11, which will come soon, but on the certification level, I don't see this happening. Anyway, I said great, as programmers are still digesting changes from Java 8 now have a chance to be certified the on latest Java 8.

Monday, March 25, 2019

Difference between Dependency Injection and Factory Design Pattern in Java Spring

Learning a Programming language like Java or Python is easy but writing production quality code is difficult. Coding is as much an art as much the Science behind it. In order to write good code, you need to carefully design your classes, their dependency and how to use that. This is important so that it can survive the constant change throughout his lifetime. If you have been coding for some time then you know that SOLID principles and Design Patterns help you to write better code. This is obvious because they are proven the solution of some common problems software developers face all around the world. But, knowing just the design pattern is not enough you also need to learn using the right design pattern in the right place.

Sunday, March 24, 2019

How to Crack Java Programming Interviews in 2019? Topics, Courses, Books, and Questions

Java Interviews are a little bit different than traditional programming interviews on tech giants and product based companies like Google, Amazon, Microsoft, or Facebook. First, even though it has questions from Data Structure and Algorithms like String or Array, you can still manage to clear Java interviews if you are not an expert on them. The questions are a little bit easier and more practical than those companies. Another very important thing about Java interviews are questions based upon Java programming language and JDK API. Since Java is also an Object-oriented programming language, you will find lots of OOP questions there.

2 Ways to Check if a String is Rotation of Other in Java - Algorithms

Write a program to check if one String is a rotation of another String is a common coding problem you will find on programming job interviews.  A String is said to be a rotation of another String, if it has the same length, contains the same characters, and they were rotated around one of the characters. For example,  String"bcda" is a rotation of "abcd" but "bdca" is not a rotation of String "abcd". One of the simplest solutions to this interesting problem is first to check if two String has the same length, if not then one String cannot be the rotation of another. If they are of the same length then just create another String by concatenating first String with itself, now check if second String is a substring of this concatenated String or not, if yes, the second String is a rotation of first.

Saturday, March 23, 2019

Difference between Stable and Unstable Sorting Algorithm - MergeSort vs QuickSort

Recently in one on the interview, after some initial questions about sorting algorithms e.g. how do you write QuickSort or difference between QuickSort and MergeSort, the interviewer asked about do you understand the difference between stable and unstable sorting algorithm? This question was new to my reader, so he says, Sorry, never heard about that. The story ended there, and Interviewer moved on to next question but like many of us, my reader went on to find more about unanswered questions and ultimately he asks me what is the meaning of a stable and unstable sorting algorithm? Some of you might be heard about it and many of you might not know about this distinction, I'll try to answer this question in this article.

Friday, March 22, 2019

Top 30 Eclipse Keyboard Shortcuts for Java Programmers

This tutorial is about 30 Eclipse keyboard shortcuts, this list is by no means complete and I will suggest you guys share eclipse shortcuts listed other than here to make this more useful. Eclipse is the most used Java development IDE and knowing these Eclipse shortcuts not only improve your productivity but also makes you more efficient. You will have more time for things you like to do. Using keyboard shortcuts also helps to impress colleagues and shows that you have a good hold on tools you used for Java Development. If you are a Java developer, who use Eclipse as your main IDE for all-purpose e.g. coding, development, and debugging, then I also suggest you take a look at Beginners Eclipse Java IDE Training Course, one of the best course to learn how to use Eclipse effectively from Java programmer's perspective.

How to Find Multiple Missing Integers in Given Array of Numbers with Duplicates in Java?

It's been a long time since I have discussed any coding or algorithm interview questions, so I thought to revisit one of the most popular array based coding problem of finding missing numbers in a given array of integers. You might have heard or seen this problem before on your programming job interviews and you might already know how to solve this problem. But, there are a lot of different versions of this problem with increasing difficulty levels which interviewers normally use to confuse candidate and further test their ability to adapt to frequent changes. In the past I have demonstrated how to find the missing number in a sorted array as well on the unsorted integer array in Java using BitSet (see here), but, with just one missing number and without any duplicates, which kinda make those problems a bit easier.

Thursday, March 14, 2019

5 Websites to Learn SQL Online for FREE

The SQL is one of the most important skills for any programmer be it a Java, C++, Python, JavaScript, or Ruby developer. Almost 95% of the Java applications use a relational database in their back-end and almost all web applications use the database. In recent years, one of the most common way to learn any programming skill is online, at your comfort of the office or home and SQL is no different. Learning SQL online has another advantage of a quick head start because you don't need to install a database and create tables to write some SELECT queries. The installation and setup is definitely a tough part for beginners and I have gone through that pain every time I have to learn a new database.

Wednesday, March 13, 2019

Top 20 String Algorithm Questions from Coding Interviews

In this article, we are going to see top 20 String based coding interview question and their solution to help programmers better prepare for interviews. The string is one of the most important data structure and available in almost every programming language like Java, C, C++, Python, Perl, and Ruby. Though there implement differ the essence remains same like String is NULL terminated character array in C but String is an object in Java, again backed by character array. The string is also available on weekly typed languages like Python and Perl.  This is why you will always find some String based coding question on programming interview.

Top 5 Data Science and Machine Learning Courses to Learn Online - Best of Lot

Many programmers and Computer Science graduates are moving towards Data Science and Machine learning hoping for better pay and career opportunity and there is a reason for it. Data Scientist and Machine Learning Specialist have been ranked the number one job on Glassdoor for last a couple of years and the average salary of a data scientist is over $120,000 in the United States according to Indeed. Data Science is not only a rewarding career in terms of money but also it provides the opportunity to solve some of the world's most interesting problems.  IMHO, that's the main motivation many good programmers are moving towards Data Science, Machine Learning, and Artificial Intelligence.

Tuesday, March 12, 2019

How to Reverse a linked list in Java Using Recursion and Iteration (Loop) - Example

This is one of the class coding problems from Programming job interviews. It may seem easy to reverse a linked list but when you go around doing the actual task, it's not that easy, especially for first-timers. There are a couple of algorithms exists to reverse a singly linked list in Java like you can use the three-pointers approach or solve this problem using a Stack, or simply using Recursion without the external stack. As I had pointed out on the earlier post about linked list, that reversing a linked list is one of the most popular linked list based data structure interview question. This means, you just can't afford to prepare this one, before going for any programming interview. Despite being so common, It's not easy to solve this problem on the fly.

Monday, March 11, 2019

5 Free Data Structure and Algorithms Books in Java Programming

In the last article, I have shared some of the best data structure and algorithms books for programmers, but those were not free. After that article, I received some feedback about how about sharing free data structure and algorithm books? Fair enough, everybody loves free eBooks, courses and PDFs, don't you? In the past, I have shared a list of free Java programming books, so I had some idea. I did some more research on the internet and checked my collection as well. Fortunately, there are a couple of good Data Structure and Algorithm books which are available for free as a PDF download or for online reading, which is what I am going to share with you all today.

Sunday, March 10, 2019

5 Best books for OCAJP8 Exam 1Z0-808 - Java 8 Certification

It's been more than a couple of years since Java SE 8 was launched on 17th March 2014 and OCAJP 8 exam went live. You might know that in order to become a Java SE 8 certified developer you need to pass two examples, the OCAJP8 (Exam 1Z0-808) and OCPJP8 (Exam 1Z0-809). The first one is called associate level certification and the second one is called professional level certification. When OCAJP8 first comes, there were not enough good books to prepare this exam and many candidates rely heavily on Java 8 books, online courses, and professional exam simulators like Whizlabs and Enthuware, but if you are going to appear for the OCAJP8 exam now, there are no such problems. In this article, you will find some of the best books to prepare for OCAJP8 exams.

Saturday, March 9, 2019

Bucket Sort in Java with Example - How Algorithm Works

In recent years, one of the questions I have increasingly seen in programming job interviews is about constant time sorting algorithms like do you know any O(n) sorting algorithm? how do they work? When I first encountered this question, I had no idea whether we can sort in constant time because even some of the fastest sorting algorithms like QuickSort or MergeSort takes O(N log N) time for sorting on their average case. After some research, mainly by going through the classic CLRS book and this DS and Algorithms course by Tim Buchalka and Goran Lochert on Udemy, I come to know that there indeed are some constant time or linear time sorting algorithms like bucket sort, counting sort, and radix sort, which can sort an array in O(n) time but they work with only a special set of input.

Friday, March 8, 2019

5 Tips to Prepare for Oracle Java Certifications (OCAJP and OCPJP)

Hello All, today, I am going to share some useful tips to prepare for Oracle's Java certifications like OCAJP and OCPJP, both associate and programmer level certification. These certifications are great for both mastering Java language as well as getting recognition for your skill which not only improves your chances of getting a Java development job but also helps you in your career growth. Though you need a bit of Java experience or knowledge to pass the exam. If you are completely new to Java then you need to first go through a comprehensive course like The Complete Java MasterClass on Udemy and learn how to program in Java, because getting certified without knowing how to program in Java is of no use.

10 Technology Jobs for Programmers and Computer Science Engineers to Earn Better Salary

If you are a Computer Science Graduate or someone who is thinking to make a career in the Software development world, or an experienced programmer who is thinking about his next career move but not so sure which field you should go then you have come to the right place. In this article, I will tell you the top 10 highest paying technical jobs you can aim for. All you need is some Programming and Coding experience and a passion for learning. Particularly the Machine learning and Data science field looking very promising for fresh Computer Science graduages, beginners and experienced programmers.

Thursday, March 7, 2019

6 Books to Learn and Master Programming and Coding - Must Read

Coding is an integral part of Programming and we all somehow learned to code by following examples here and there. Yes, I am talking about both self-taught programmer and Computer Science Graduates. You can learn Coding easily if you are dedicated, but what is more difficult is to write good code. You can easily find programmers in Java, C++, Ruby or Python, but finding programmers, who are also a good coder is very difficult. Some universities have a good curriculum and practical classes to teach coding better than others, but most of these great coders are self-taught Programmers, who learned by reading books, joining online courses and doing things by their own.

Wednesday, March 6, 2019

Spring Hello World Example in Java using Dependency Injection and XML Configuration

Hello All, In this Spring framework tutorial, you will learn how to write the hello world example in the Spring framework. This should be your first tutorial to start learning Spring framework, as it gets the ball rolling. While coding and running this example, you learn a lot about Spring framework, Spring XSD files, necessary JAR files, and more importantly how Spring framework works. This HelloWorld program in Spring framework is an extension of the classical Java hello world program, which you might have seen earlier. This program is written using the Dependency Injection design pattern by using the Spring Framework's IOC container.  Even though now you can configure Spring dependency using annotations and Java configuration, this example uses a traditional XML way to configure dependencies.

Top 5 Online Courses to Learn Web Development in 2019

Hello guys, if you are wanted to learn Web Development this year and thinking that it's too late to make that goal than let me tell you it's never too late. In this article, I am going to share some of the best Web Development courses you can take to learn online by yourself. If you are a regular reader of this blog then you might know that earlier I have shared about The 2019 Web Developer RoadMap which outlines how you can become a Modern Web Developer everybody wants to hire. In that post, I have explained how you can learn everything about Programming and Web Development from scratch and with no coding experience.

Tuesday, March 5, 2019

How to deal with java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet in Spring Application

The java.lang.ClassNotFoundException: org.springframework.web.servlet.DispatcherServlet error comes when you deploy a Spring MVC application into Tomcat or Jetty and Servlet container not able to found this class, which usually found in the spring-webmvc.jar file. The DispatcherServlet is the core of Spring MVC framework, it implements the FrontController pattern and intercept all HTTP requests sent to your Web application and subsequently route it to correct controller based upon URL mapping.

Monday, March 4, 2019

Top 5 React Native Online Courses for Programmers and Mobile Developers - Best of Lot

If you are a web developer who wants to go into the massive world of mobile app development but don't want to spend time learning Java or Kotlin for Android development, or Objective C or Swift for iOS development then React Native could be a great tool for you. React Native is an extension of React, a popular JavaScript framework to develop web applications, which allows you to build native Android and iOS applications in JavaScript. Unlike Ionic and Cordova which promotes write once run everywhere but doesn't offer you to create a native app, React Native does convert your code into native code, especially for GUI.

Saturday, March 2, 2019

Top 10 Courses to Learn JavaScript in 2019 - Best of Lot

There is no doubt that JavaScript is the most popular programming language at this moment and it's also confirmed by StackOverFlow's 2018 Survey. You can build static websites, web applications, native mobile applications (yes you can do that too), desktop applications and even server-side application in JavaScript. It also makes you a hundred time more employer as there are tons of web development jobs out there. Because of that ore and more developers are learning JavaScript to become a web developer.

Difference between @RestController and @Controller Annotation in Spring MVC and REST

The @RestController annotation in Spring MVC is nothing but a combination of @Controller and @ResponseBody annotation. It was added into Spring 4.0 to make the development of RESTful Web Services in Spring framework easier. If you are familiar with the REST web services you know that the fundamental difference between a web application and a REST API is that the response from a web application is generally view (HTML + CSS + JavaScript)  because they are intended for human viewers while REST API just return data in form of JSON or XML because most of the REST clients are programs. This difference is also obvious in the @Controller and @RestController annotation.