How to Run a .Jar Java File: 10 Steps
Running a Java Archive (JAR) file is easy if you follow these ten simple steps. JAR files are created by developers to distribute Java-based applications and libraries with all the essential components bundled together.
Step 1: Install the Java Runtime Environment (JRE)
First and foremost, you need to install the Java Runtime Environment (JRE). Visit the official Oracle website to download the JRE for your system. Install it following their instructions.
Step 2: Save the JAR file
Save the JAR file in a proper location on your computer. Create a directory specifically for the JAR file if it’s not provided already.
Step 3: Open Command Prompt (Windows) or Terminal (Mac/Linux)
For Windows users, press ‘Win + R’, type ‘cmd’, and hit Enter to open the Command Prompt. For Mac or Linux users, open Terminal from your Applications folder or through a search.
Step 4: Navigate to the JAR file location
Using the ‘cd’ command, navigate to the directory where you saved the JAR file in Step 2. For example, type ‘cd C:\Users\John\Desktop\MyApp’ and press Enter.
Step 5: Check if “java” command works
Type ‘java -version’ and press Enter. This command checks whether your system recognizes “java” as a valid command. If it returns information about your installed Java version, proceed to Step 6. If not, there may be an issue with your Java installation or environment variables.
Step 6: Use “java -jar” command
Type ‘java -jar FileName.jar’, replacing ‘FileName’ with the name of your JAR file. Press Enter. This should launch the application.
Step 7: Troubleshoot errors
If an error appears, check that your Java installation is complete and that your environment variables are correctly configured. Ensure you typed the JAR file name correctly.
Step 8: Create a .bat or .sh file for easy execution (Optional)
You can create a batch (.bat) file on Windows or a shell (.sh) script on Mac/Linux to make launching your JAR file easier.
Simply create a new text document with the ‘java -jar FileName.jar’ command and save it with the appropriate extension. Double-click the file to launch your Java application.
Step 9: Set JAVA_HOME environment variable (Optional)
If you’re still facing issues, ensure the JAVA_HOME environment variable is set correctly. Add it to your system if it’s missing.
Step 10: Update Java (Optional)
Keep your Java installation up-to-date to avoid potential incompatibilities or security vulnerabilities.
Congratulations! You’ve successfully run a JAR file using these ten straightforward steps. These instructions should serve as a helpful guide for running Java applications and libraries, regardless of their complexity.