How to Run a Java File (.jar)

Today, Mytour will guide you on how to open and execute executable JAR files on your Windows or Mac computer. JAR files (Java Archive) contain data that can be used with Java programs. Most JAR files are simply containers for data that other programs need to run Java; therefore, you cannot run these files directly, and nothing happens when you double-click them. Similarly, most executable JAR files are downloaded as installation files for setting up applications or programs. If you encounter issues opening a file, ensure your JAR file is compatible with your operating system.

Install Java on your computer if you haven't already. You cannot run JAR files without Java installed. Visit the website https://www.java.com/en/download/ and click the Free Java Download button below the latest Java version, then install Java once the file is downloaded.

• You may need to restart your computer to complete the Java installation.

Double-click the JAR file. If the file is executable and Java is installed, it will open. Otherwise, proceed to the next step.

• A pop-up window may appear asking which program to use. Select Java(TM) and click OK.

Ensure the JAR file is executable. JAR files used for installing programs differ from "library" JAR files that store data for Java programs. Non-executable JAR files lack an interface, making them impossible to run.

• For example, many JAR files in a program's data folder are not executable.
• If downloading a JAR file online, ensure you select the Windows version, not the Mac version.

Double-click the JAR file again. If the file still doesn't open, it means the file you're trying to access is not executable and cannot be "run" in the conventional sense.

Install Java on your computer if it's not already installed. You cannot run JAR files without Java. Visit https://www.java.com/en/download/ and click the Free Java Download button below the latest Java version, then install Java once the file is downloaded.

• When installing a non-Apple file on a Mac, click OK on the warning prompt, then go to the Apple menu, select System Preferences, click Security & Privacy, unlock the menu, click Open Anyway next to the file name, and finally click Open in the prompt before installing the file.

Try double-clicking the JAR file. If the file is executable and Java is installed, it will open. Otherwise, proceed to the next step.

Ensure the JAR file is executable. JAR files used for setting up programs differ from "library" JAR files that store data for Java programs. Non-executable JAR files lack an interface, making them impossible to run.

• For example, many JAR files in a program's data folder are not executable.
• If you downloaded the JAR file from the internet, ensure you selected the Mac version, not the version for another operating system.

Double-click the JAR file again. If the file still doesn't open, it means the file you're trying to access is not executable and cannot be "run" in the conventional sense.

• Java programs work across all platforms. If a program doesn't work, it may be improperly coded or highly specialized (requiring specific system resources or other programs).
• A file with a .jar extension can be either a program or a library. If it's a library, it lacks an executable class inside, making it impossible to run.

• Java is safer than most programming languages, but malicious software written in Java still exists. Be cautious when running JAR files downloaded from the internet.