The JRE is part of the JDK, so you don’t have to install it additionally if you have already installed the JDK. (Optional) A Java Runtime Environment (JRE) that will execute the compiled code.For other platforms, see Oracle’s JDK Installation Guide or the official instructions for installing OpnJDK version 11 or above. For Ubuntu, you can follow the JDK installation instructions in Option 1 from How To Install Java with Apt on Ubuntu 22.04. You can compile your source either on your local computer or on a remote server in the cloud. To compile the source code, you’ll use the default Java compiler called javac. A compiler provided by the Java Development Kit (JDK).For other operating systems, including Mac and Windows, see the download options for Java installation. For Ubuntu and Debian, follow the steps for Option 1 in our tutorial, How To Install Java with Apt on Ubuntu 22.04. Java (version 11 or above) installed on your machine.Once you’re finished, you’ll be able to write and run basic Java code. By creating a “Hello, World” program, you’ll start learning Java’s basic syntax as well as the compilation and execution process of a Java program. It’s a complete first program for beginners, and it’s a good way to make sure your environment is properly configured. The “Hello, World!” program is a classic and time-honored tradition in computer programming. In this tutorial, you’ll create a “Hello, World!” program in Java. If you’re used to languages such as PHP and Python, which allow source code to be executed directly, then compiling the code first will be a new step in the development process. For developers, this means that you have to compile its source code before you can run it. Java achieves high performance because it executes compiled (that is, machine-optimized) code. One of its unique benefits is that it is cross-platform: once you create a Java program, you can run it on many operating systems, including servers (Linux/Unix), desktop (Windows, macOS, Linux), and mobile operating systems (Android, iOS).

Java is a mature and well-designed programming language with a wide range of uses, from being studied in class to running commercial applications of any size. There are several ways to use this feature, as well as some limitations and things to keep in mind.The author selected the Free and Open Source Fund to receive a donation as part of the Write for DOnations program. This can be a great way to learn how to use Java or explore new features within the Java API, without having to go through the cruft of compiling and then executing code. This works by the java launcher automatically invoking the compiler and storing the compiled code in-memory. In JDK 11, Java introduced the ability to launch a single-file source-code program with the java launcher, without first needing to explicitly compile the source code. Single-File Source-Code Program Execution

Java programs with source code