JAR files are typically used to distribute applications that can be run with the Oracle Java Runtime Environment (multiplatform). If you have JRE installed and set as the default program associated with JAR files, you can simply double-click the JAR file to run it. When you do this on a Mac, Apple Jar Launcher (bundled with macOS) passes the JAR file to JRE, or JVM, which runs the file.
You can also view, extract, run, and create JAR files with the Java Archive Tool provided as part of the Java Development Kit (JDK) included in the Oracle Java SE Development Kit. The Java Archive Tool is a command-line utility and here are the commands associated with the different capabilities:
To view a JAR file - jar tf jar fileTo extract a JAR file - jar xf jar fileTo run a JAR file - java -jar app.jarTo create a JAR file - jar cf jar file input file(s)NOTE: If you are looking to extract the contents from a JAR file, you can use various decompression utilities, such as Corel WinZip (Windows), Corel WinZip Mac (Mac), RARLAB WinRAR (Windows), and 7-Zip (Windows).