This article shows you how to open and run JAR files on Windows and Mac systems. JAR files (English acronym for "Java Archive") contain data and information that will be used by other programs created in Java. In most cases, JAR files are simple libraries that contain classes that Java programs refer to to work properly, so you can't run this type of file and nothing will happen by double clicking on them. Similarly, most executable JAR files are distributed on the web as installation files for installing applications and programs. In this case, it is therefore essential to verify that you have the correct JAR file according to the operating system in use, if you are having problems or difficulties in using it.
Steps
Method 1 of 2: Windows systems
Step 1. Install Java on your computer if you haven't already
If you don't have the Java environment installed on your system, you won't have the ability to run JAR files. To do this, go directly to the official Java website using this URL https://www.java.com/it/, then press the button Free Java download placed in the center of the page that appeared and follow the instructions to download the latest version of Java. Once the download is complete, proceed to install it.
You may need to restart the computer to finish installing Java on your computer
Step 2. Select the JAR file under consideration with a double click of the mouse
If it is an executable file and the Java environment is properly installed on your system, it should open automatically. Otherwise, continue reading.
A system dialog may appear asking you to select the program with which to open the JAR file. In this case you will have to choose the option Java (TM) and press the button OK.
Step 3. Make sure the JAR file is an executable file
JAR files created for installing programs and applications are different from JAR files that are used as "libraries" whose purpose is to store data and classes that will be used by other Java programs. Since JAR libraries do not have an interface, as is the case with executable JAR files, they cannot be run by the user.
- For example, many of the JAR files present in the installation folder of a Java program are not executable files.
- If you have downloaded a JAR file from the web, make sure you have saved the correct version for Windows and that you have not accidentally downloaded the one for Mac.
Step 4. Update the Java environment
If you get any error messages when you try to run the JAR file, you may need to update the version of Java installed on your system. To do this, follow these instructions:
-
Access the "Start" menu by clicking the icon
Windowsstart ;
- Scroll through the list of applications and programs in the "Start" menu to locate and select the folder Java;
- Select the option Check for updates;
- Now press the button Update now placed inside the card Update.
Step 5. Double click on the JAR file again
If it doesn't open, it simply means that the file is not an executable file, so it contains data and classes that are useful for other programs.
Method 2 of 2: Mac
Step 1. Install Java on your computer if you haven't already
If you don't have the Java environment installed on your system, you won't have the ability to run JAR files. To do this, go directly to the official Java website using this URL https://www.java.com/it/, then press the button Free Java download placed in the center of the page that appeared and follow the instructions to download the latest version of Java available. Once the download is complete, proceed to install it.
A warning message appears when you install a program or application that was not manufactured or certified by Apple. To proceed with the installation, press the button OK present in the pop-up window that appeared, access the menu Apple, select the option System Preferences, click the icon Security and Privacy, enable the changes, press the button Open anyway next to the file name and select the option You open when required.
Step 2. Select the JAR file under consideration with a double click of the mouse
If it is an executable file and the Java environment is correctly installed on the system, it should open automatically. Otherwise, continue reading.
Step 3. Make sure the JAR file is an executable file
JAR files created for installing programs and applications are different from JAR files that are used as "libraries" whose purpose is to store data and classes that will be used by other Java programs. Since JAR libraries do not have an interface, as is the case with executable JAR files, they cannot be run by the user.
- For example, many of the JAR files in a Java program installation folder are not executable files.
- If you have downloaded a JAR file from the web, make sure you have saved the correct version for Mac and that you have not downloaded the one for another hardware platform (e.g. Windows).
Step 4. Update the Java environment
If you get any error messages when you try to run this JAR file, you may need to update the version of Java installed on your system. To do this, follow these instructions:
-
Access the menu Apple clicking the icon
Macapple1 ;
- Select the option System Preferences;
- Click the icon Java;
- Access the card Update;
- Push the button Update now.
Step 5. Double click on the JAR file again
If it doesn't open, it simply means that the file is not an executable file, so it contains data and classes that are useful for other Java programs.
Advice
- Programs written in Java should be able to run on any hardware platform. If the software in question does not run correctly, it means that it was not created properly or that it requires the use of system resources or other programs specific to a particular environment.
- JAR files can contain a program or a library. In this second case, it means that they do not contain any executable classes and consequently there is no use in running them.
