Christa  Stehr

Christa Stehr

1602320459

Install and run multiple Java versions on Linux and MacOS using SDKMAN

If you are a Java developer, you may need to install multiple Java versions on your machine. You may use Java8 or Java11 in your project, but want to learn newer versions of Java. Or maybe you are working on two different projects where two different versions of Java are used.

One way to achieve this is to install multiple Java versions and configure different Java versions manually. In that case, you have to modify a few environment variables when you need to switch your Java version. The other elegant and convenient way is to use the SDKMAN.

SDKMAN is a Software Development Kit Manager for managing parallel versions of multiple Software Development Kits on most Unix based systems. It allows us to install, remove, switch and list candidate versions of different SDKs including Java (e.g., JDK, Ant, Dotty, Gradle, Scala, and many more).

Here I will show how to manage multiple Java version on your UNIX based machine using SDKMAN. By reading this article, you will learn the following:

  • Install SDKMAN
  • List candidate JDKs using SDKMAN
  • Install multiple candidate JDKs using SDKMAN
  • Switch candidate JDKs using SDKMAN
  • Remove/Uninstall JDK using SDKMAN

The instructions are valid for most of the UNIX based operating systems including MacOS, any Linux OS (Ubuntu, Debian, MINT, Manjaro, OpenSUSE), FreeBSD, Solaris, Cygwin.

#java #linux #macos #ubuntu #programming

What is GEEK

Buddha Community

Install and run multiple Java versions on Linux and MacOS using SDKMAN
Tyrique  Littel

Tyrique Littel

1600135200

How to Install OpenJDK 11 on CentOS 8

What is OpenJDK?

OpenJDk or Open Java Development Kit is a free, open-source framework of the Java Platform, Standard Edition (or Java SE). It contains the virtual machine, the Java Class Library, and the Java compiler. The difference between the Oracle OpenJDK and Oracle JDK is that OpenJDK is a source code reference point for the open-source model. Simultaneously, the Oracle JDK is a continuation or advanced model of the OpenJDK, which is not open source and requires a license to use.

In this article, we will be installing OpenJDK on Centos 8.

#tutorials #alternatives #centos #centos 8 #configuration #dnf #frameworks #java #java development kit #java ee #java environment variables #java framework #java jdk #java jre #java platform #java sdk #java se #jdk #jre #open java development kit #open source #openjdk #openjdk 11 #openjdk 8 #openjdk runtime environment

Christa  Stehr

Christa Stehr

1602320459

Install and run multiple Java versions on Linux and MacOS using SDKMAN

If you are a Java developer, you may need to install multiple Java versions on your machine. You may use Java8 or Java11 in your project, but want to learn newer versions of Java. Or maybe you are working on two different projects where two different versions of Java are used.

One way to achieve this is to install multiple Java versions and configure different Java versions manually. In that case, you have to modify a few environment variables when you need to switch your Java version. The other elegant and convenient way is to use the SDKMAN.

SDKMAN is a Software Development Kit Manager for managing parallel versions of multiple Software Development Kits on most Unix based systems. It allows us to install, remove, switch and list candidate versions of different SDKs including Java (e.g., JDK, Ant, Dotty, Gradle, Scala, and many more).

Here I will show how to manage multiple Java version on your UNIX based machine using SDKMAN. By reading this article, you will learn the following:

  • Install SDKMAN
  • List candidate JDKs using SDKMAN
  • Install multiple candidate JDKs using SDKMAN
  • Switch candidate JDKs using SDKMAN
  • Remove/Uninstall JDK using SDKMAN

The instructions are valid for most of the UNIX based operating systems including MacOS, any Linux OS (Ubuntu, Debian, MINT, Manjaro, OpenSUSE), FreeBSD, Solaris, Cygwin.

#java #linux #macos #ubuntu #programming

Seamus  Quitzon

Seamus Quitzon

1599522905

How to Install Multiple Versions of Java on the Same Machine

Some time back, I wrote the article Java Lambda Expression Explained with Example, but it was easy for me to explore Java 8 because I was using it in my project and allowed to install it. But in my current project, we are still using Java 8, and now, I want to upgrade and learn Java 11, but unfortunately, I cannot install it.

And this happens a lot with Java developers. Sometimes, you want to learn and explore the latest version of Java, but you cannot install it on your machine because you and your team are working on an older version, e.g. Java 8, and you don’t want to accidentally break your project.

Or, suppose you are working on multiple projects, some of which use Java 8 and some of which are new projects using Java 11. So, in order to work on both of these projects, you will need to install multiple versions of the JDK on your machine and be able to switch between them.

What if there is a way to install multiple versions of Java and turn different versions on and off, depending on your needs.

Well, there is a tool called SDKMan which allows us to do just that. According to their website:

SDKMan! is a tool for managing parallel versions of multiple S oftware Development Kits on most Unix-based systems. It provides a convenient Command Line Interface (CLI) and API for installing, switching, removing, and listing Candidates.

Some points about SDKMan are as follows:

  1. SDKMan is free to use and is developed by the open-source community.
  2. SDKMan is written in bash and only requires curl and zip/unzip programs to be present on your system.
  3. We do not need to worry about setting the _HOME and PATH environment variables because SDKMan handles them automatically.

Installing SDKMan

SDKMan can run on any UNIX-based platforms such as Mac OSX, Linux, Cygwin, Solaris, and FreeBSD, and we can install it using the following commands:

$ curl -s "https://get.sdkman.io" | bash

$ source “$HOME/.sdkman/bin/sdkman-init.sh”


We can verify the installation using `sdk version` and `sdk help` commands, which will give us complete help with the usage of the `sdk `command.

> Because SDKMan is written in [bash](https://www.gnu.org/software/bash/) and only requires [curl](http://curl.haxx.se/) and [zip/unzip](http://www.info-zip.org/) to be present on your system, you can install SDKMan on Windows as well either by first installing [Cygwin](https://www.cygwin.com/install.html) or [Git Bash for Windows](https://git-scm.com/download/win) environment and then running the above commands.

#java #jvm #java 9 #jdk #java 11 #java 10 #jdk 11 #versions

Samanta  Moore

Samanta Moore

1620458875

Going Beyond Java 8: Local Variable Type Inference (var) - DZone Java

According to some surveys, such as JetBrains’s great survey, Java 8 is currently the most used version of Java, despite being a 2014 release.

What you are reading is one in a series of articles titled ‘Going beyond Java 8,’ inspired by the contents of my book, Java for Aliens. These articles will guide you step-by-step through the most important features introduced to the language, starting from version 9. The aim is to make you aware of how important it is to move forward from Java 8, explaining the enormous advantages that the latest versions of the language offer.

In this article, we will talk about the most important new feature introduced with Java 10. Officially called local variable type inference, this feature is better known as the **introduction of the word **var. Despite the complicated name, it is actually quite a simple feature to use. However, some observations need to be made before we can see the impact that the introduction of the word var has on other pre-existing characteristics.

#java #java 11 #java 10 #java 12 #var #java 14 #java 13 #java 15 #verbosity

Samanta  Moore

Samanta Moore

1623861240

What is Assertion in Java? How to use Assertion in Java

Table of Contents

What is Assertion in Java?

The assertion in Java is used to ensure the correctness of any program’s assumptions as the assertion is assumed to be true when it is executed. The Java Virtual Machine throws an error named AssertionError if the assertion is false. The assertion in Java has found its application mainly for testing purposes. Boolean expressions are used along with assertion statements. An assertion is a statement, and the ‘asset’ keyword is used to carry out an assertion in Java.

#full stack development #assertion in java #assertion in java #assertion in java #what is assertion in java #how to use assertion in java