How to setup and run Java on your machine

In this post, we will set up Java on our computer and run a simple program that prints Hello World.

First thing first

To develop our awesome Java applications, we need to install the Java Development Kit (JDK). But what is the JDK?? JDK is a software development environment that is bundled with the necessary tools and libraries to develop and run Java programs. The JDK contains the Java Virtual Machine (JVM) and the Java Runtime Environment (JRE).

Difference between JVM, JRE, and JDK

• JVM is a virtual machine that compiles Java programs into bytecode
• JRE is a runtime environment that is responsible for running the compiled bytecode. If you want only to run the Java programs and are not interested in developing, you can use JRE.
• JDK contains JVM + JRE + Development tools so we can develop, compile and run Java programs.

Setting up JDK

There are a lot of implementations of JDK. In this article, we will install the Oracle JDK.

First of all, visit the following link https://www.oracle.com/java/technologies/downloads/ and download the package according to your operating system. Then install the software like any other software.

Verifying the installation

To verify that JDK is installed successfully or not, open your terminal and type
java --version

then press enter. You will do something like this :

Congratulations! You have successfully installed Java

Running our first program

• Open a code editor like VS Code or any other of your favorite code editors.
• Create a new file named Hello.java.
• Now, open the Hello.java file and write the following program

class Hello {
      public static void main(String[] args) {
          System.out.println("Hello World!");
      }
  }

• The file name and the class name must be the same.
• Save the file
• Open the terminal where the Hello.java file is located.
• Type javac Hello.java and press enter to compile the Java program.
• Now you will see a Hello.class file is located in the same directory.
• Open the terminal again, type java Hello and press enter.
• Now, you will see Hello World! on the console.

Congrats! you have successfully run your first Java program.
This article was also published in Hashnode

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