Hello guys, if you are interested in learning Spring Boot and looking for some excellent resources, e.g. books, tutorials, and online courses to start with, then you have come to the right place. Earlier I have shared some great books to learn Spring Framework, including Spring Boot (see), and today, I'll share some of the best online Spring Boot courses you can join to learn Spring Boot by yourself. In the past, I was a big fan of learning from a book, but online courses have changed that completely. Now I prefer to start with an online course, like Spring Boot 3, Spring 6 & Hibernate for Beginners, and then move on to a book like Spring Boot in Action for more comprehensive learning. Anyway, before going through those Spring Boot courses, let's first revise what Spring Boot is, and its benefits, and why you should learn it.
Friday, March 29, 2024
Wednesday, March 27, 2024
How to Compare Date in SQL Server Query? Finding All Rows Between Two Dates
It's tricky to use dates in the SQL server query, especially if you don't have good knowledge of how DateTime type works in the SQL server. For example, one of the frequently asked SQL queries on the interview is to "select all rows where the date is 20151007?" How would you do that? Does the following SQL Query will work correctly
select * from table where date = '20151007'
It may or may not, it entirely depends on upon data in your table. When you only provide date part of a DateTime variable, it uses '00:00:00.000' for the time part.
select * from table where date = '20151007'
It may or may not, it entirely depends on upon data in your table. When you only provide date part of a DateTime variable, it uses '00:00:00.000' for the time part.
Labels:
Microsoft SQL Server
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SQL
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SQL Interview Questions
Tuesday, March 26, 2024
Top 50 Java Programs from Coding Interviews
Coding is an integral part of any programming job interviews, and Java development interviews are no exception. I would even suggest you should never hire anyone without testing their coding skill, coding is also an art, and more often than a good code is an excellent developer as well. If you look at tech giants like Amazon, Facebook, and Google they thoroughly test the coding skill of any developer they hire, notably Amazon who first send online coding exercises to filter Java programmers who can code. This online test usually gives you requirements and ask you to write a program in a limited time, usually 2 to 3 hours. The application should meet the output provided by the exercise itself. These type of tasks are very tough to crack if you don't have excellent coding skill.
Monday, March 18, 2024
What is N+1 SELECT Problem in Hibernate? Strategies to avoid this?
In some cases while using Hibernate for object-relational mapping, you will encounter the N+ 1 select problem. That is, Hibernate will execute (n+1) queries to populate a list of records of size n, I mean 5 SELECT queries will be required to populate 4 records. This happens when each object contains reference of another object which needs to be populated. For example, suppose you have list of authors and you want to print out title of books written by each other. A naive ORM will first do a SELECT query to load all authors and then execute another N SELECT query to load book for each author. That's your N + 1 SELECT problem because it involves N+1 database roundtrips'. There are some mechanisms suggested by Hibernate that can be used to mitigate this risk e.g. EAGER fetching mode.
Labels:
hibernate
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hibernate interview questions
Sunday, March 17, 2024
Top 22 Apache Tomcat Interview Questions Answers for Java JEE Developers
The Apache Tomcat is one of the most popular web server used to deploy Java web application comprising HTML, JavaScript, Servlet and JSP. If you have ever worked in a Java web application you might have found yourself using Tomcat everywhere, from test environment to production. It is the defacto standard for deploying Java Web applications without EJB because using application server like WebSphere or WebLogic is both costly and superfluous for such web application. As a Java developer, working in Java and Spring based web applications, you should know some basic and advanced detail of Tomcat server to efficiently support your Java web app and troubleshoot any issue arising on request processing.
Labels:
interview questions
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Java web tutorial
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Tomcat
Thursday, March 14, 2024
Top 10 HTTP Status Code Every RESTful web Service Developer Should know
A good knowledge of HTTP protocol is must for a RESTful Web Service developer because REST uses HTTP principles and a good portion of its popularity is due to HTTP itself. One of the important part of HTTP is the status code, which gives useful information related to client request. They are also known as HTTP response code because they are sent in header on HTTP response by Server to indicate what happened with client's request. The status codes ranges from 100 to 500 but not all of them are valid and useful. Instead the first number e.g. 1xx or 2xxx denotes the class of status codes.
Labels:
Java HTTP Tutorial
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REST
Saturday, March 9, 2024
10 Example of Gson in Java - JSON tutorial
The Gson library is a gift from Google to Java developers. It provides the simplest but powerful mechanism to deal with JSON documents in Java. By using Gson library, you can parse JSON String to generate Java objects, serialize a Java object to create a JSON document. You can even pretty print JSON String by setting some option to the Gson class, which is the main helper class to interact with Gson library. It also provides mechanism to deal with nulls e.g. you can include null on JSON String or you can omit them. By default Gson print JSON in compact format where null fields are not exported to JSON document but null within array and list are exported.
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Gson
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Java JSON tutorial
Thursday, March 7, 2024
Difference between Servlet and Filter in Java
Servlet and Filter are two of the essential concepts defined in Servlet specification. They are core of any web application because most of the request will pass through them. This is why they are also very popular on Java Web developer interviews. What is the difference between a Servlet and a Filter is one of the most common and interesting interview question related to Servlet. If you can explain the difference clearly, you improve your chance of hiring a lot. In order to understand and explain the difference, you must understand what is the purpose of Servlet and Filter, How they work and how they are used in various web applications.
Labels:
JSP and Servlet
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spring interview questions
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spring security
Sunday, March 3, 2024
Top 27 Gson Interview Questions with Answers for Java Developers
Hello guys, parsing and creating JSON is a very common task in any Java application, particularly spring based application and that's why its important for a Java developer to not just understand the JSON format but also to be familiar with the important JSON parsing libraries in Java like Gson and Jackson. It's not just important for your day to day Java development work but also for interviews as there is a increased focus on checking if candidate is familiar with key JSON libraries like Jackson or Gson or not. Since I shared Java interview questions on core Java topics like concurrency, abstract class, static, and final modifier, a lot of my reader asked me to share JSON related interview questions as well.
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Gson
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Java JSON tutorial
Friday, March 1, 2024
Difference between known_hosts and authorized_keys file in SSH - Linux
If you have used SSH to login into remote host in Linux, you might have come across these two files stored under the .ssh directory in your home directory e.g. ~/.ssh. Both files are used in the login process for authentication, but the main difference between known_hosts and authorized_keys files are that, known_host is used for server authentication, while authorized_keys are used for client or user authentication. SSH allows login using both password and private keys, you might have heard about trusted SSH connection between two host to download files without entering password, this is achieved using public and private keys.
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linux
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Linux interview questions
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SSH
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unix
2 ways to Split String with Dot (.) in Java using Regular Expression? Examples
You can use the split() method of java.lang.String class to split a string based on the dot. Unlike comma, colon, or whitespace, a dot is not a common delimiter to join String, and that's why beginner often struggles to split a String by dot. One more reason for this struggle is the dot being a special character in the regular expression. If you want to split String on the dot you need to escape dot as \\. instead of just passing "." to the split() method. Alternatively, you can also use the regular expression [.] to split the String by a dot in Java. The dot is mostly used to get the file extension as shown in our example.
Thursday, February 29, 2024
What is the ContextLoaderListener in Spring MVC? What does it do?
The ContextLoaderListener is one of the important component of Spring MVC framework. It is like any listener defined by Servlet specification and specified in web.xml using <listener> tag. It is loaded when Spring MVC based web application is deployed in any Servlet container e.g. Tomcat. The ContextLoaderLister of Spring MVC is responsible for loading root ApplicationContext for Spring. The application context is the place where Spring bean lives. If you need reference to a Spring bean either its auto-wired or injected by framework or you can get it directly from application context. In Spring MVC based web application, there can be multiple application context e.g. root application context and context local to each DispatcherServlet.
Labels:
spring
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spring interview questions
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spring mvc
Thursday, February 15, 2024
Review - Is Grokking the System Design interview Course on DesignGuru Worth it?
Hello guys, we are here again today for another exciting topic to discuss. But today, we will not discuss something related to Java or any other language or spring boot. Today, we will discuss something that is immensely practical and has the potential to land you very high-paying jobs. Today we are going to review a course that focuses on System Design! System Design is crucial for coding interviews! And it's also one of the most challenging topics to master. I have shared the best System design courses for coding interviews in the past. Today, I will review one of the top system design courses for technical discussions, Grokking the System Design Interview by Design Gurus.
Tuesday, February 13, 2024
Top 5 React and Redux Courses to Learn Online in 2024 - Best of Lot
If you are a Web developer or someone passionate about web development and looking for some awesome courses to learn React or React JS, a popular JavaScript framework to develop a component-based user interface then you have come to the right place. Facebook's React library has taken the front-end development world by storm. More and more people have started using React even in favor of Google's Angular, another popular front-end development framework. Well, I am not going into the classic debate of Angular vs React as both the framework has their own advantage and disadvantage but if you have chosen to learn React, you have made the right decision.
Labels:
courses
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online resources
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React JS
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web development
Monday, February 12, 2024
Top 10 System Design Courses for Beginners and Experienced Developers in 2024 - Best of Lot
Hello guys, if you are preparing for System design interview and looking for best online courses to learn essential System design concepts like load balancing, API Gateway, scalability, Microservices architecture as well as learn how to solve popular System design questions like how to design YouTube, WhatsApp, Parking Lot, Library System as well when to use NoSQL and SQL then you have come to the right place. In the past, I have shared best System Design Books, Free System design courses, System design prep guide, and System Interview Questions and in this article, I am going to share best System Design Courses for beginners and experienced Software Engineer to level up their System Design skills in 2024.
Labels:
courses
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software architecture
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System Design
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