In Java, the concept of immutable refers to classes whose objects do not change information after they are instantiated. Normally, to declare an immutable class, we would: Declare this class as final so that no class can extend from it. Declare the fields of that… Read More

In Java, to prevent the inheritance of a certain class, we will use the final keyword to declare that class. Examples are as follows:

Class Test will not be able to inherit JavaExample class because this JavaExample class is declared with final: A need… Read More

We often use the Java server runtime to run Java web applications such as Tomcat, Jetty, … From Java version 18, by default, Java also supports us to run a server runtime using the jwebserver command. By default, the jwebserver command will run a web… Read More

A need that we often meet is how to know what version of the application we are running, so we can know what features the application is supporting up to this version. In Java, depending on what application you are using, Web application or Desktop… Read More

Java Module System was introduced by Java from Java 9 to solve some problems of Java that if you notice you will see how its necessary? NoClassDefFoundError: This error occurs while our Java program is running. The JVM cannot find the class needed to execute… Read More

Java allows us to define a class that belongs to another class, for example:

Class is defined inside another class, we call it nested class and this other class is called outer class. In my example above, the Builder is a nested class and… Read More

The instanceof operator in Java is an operator used to check if this object is an instance of a certain class or interface or not? The return result of this operator will be true if the object is an instance of the class you are… Read More

Previously, when declaring a multi-line text in Java, for example:

We will usually declare the following:

Result: But from Java 13 onwards, you do not need to declare so anymore. Java now supports the text blocks with the ability to declare multiple lines… Read More

To work with the Java programming language, the first thing you need to do is set up the environment to run the application with the Java JDK. In this article, I will guide you through the steps to install Java JDK! To install Java JDK,… Read More

In the tutorial about @Entity and @Table annotation in JPA, I mentioned to you the concept of Java Bean, they are POJOs with at least one constructor with no parameters. We often use Java Bean to contain information of an object. To ensure that the… Read More