install_java

In this tutorial, we will install java and try our first program :

1. Verify that you have not already installed Java
2. Install Ubuntu’s default JDK
3. Test Java on the command line
4. Set JAVA_HOME globally for all Ubuntu users
5. Write your first program
6. Compile the program
7. Run the program

Verify that you have not already installed Java

  $java -version

Install Ubuntu’s default JDK

  $sudo apt-get update
  $sudo apt install default-jdk

Test Java on the command line

  $java -version

Set JAVA_HOME globally for all Ubuntu users

  $update-alternatives --config java
  $sudo nano /etc/environment
  $JAVA_HOME="/lib/jvm/java-11-openjdk-amd64/bin/java"
  ctrl+o
  enter
  ctrl+x
  $source /etc/environment
  $echo $JAVA_HOME

Write your first program

  $ gedit Hello_World.java
  ![image](https://github.com/ykarray/install_java/blob/main/java.png)

Compile the program

  $javac Hello_World.java

Run the program

 $java Hello_World