How to Check Java Version

Introduction

Java is a popular programming language used for developing a wide range of applications, from web and mobile to enterprise-level software. It is essential to know the version of Java installed on your system to ensure compatibility and troubleshoot any issues. In this article, we will explore different methods to check the Java version on various operating systems.

1. Checking Java Version on Windows

On Windows, you can check the Java version using the Command Prompt or the Control Panel. Follow the steps below:

Using Command Prompt:

1. Open the Command Prompt by pressing Windows + R and typing cmd.
2. In the Command Prompt, type the following command and press Enter:Copy codejava -version
3. The output will display the installed Java version information.

Using Control Panel:

1. Press Windows + R to open the Run dialog box, type control and press Enter.
2. In the Control Panel, select Programs or Programs and Features.
3. Look for Java in the list of installed programs.
4. Double-click on Java to open the Java Control Panel.
5. In the Java Control Panel, go to the General tab and click on About.
6. The installed Java version will be displayed in the popup window.
7. Checking Java Version on macOS

To check the Java version on macOS, you can use the Terminal application. Follow the steps below:

1. Open the Finder and navigate to Applications > Utilities.
2. Open the Terminal application.
3. In the Terminal, type the following command and press Enter:Copy codejava -version
4. The output will display the installed Java version information.
5. Checking Java Version on Linux

On Linux, you can check the Java version using the Terminal. Follow the steps below:

1. Open the Terminal application.
2. In the Terminal, type the following command and press Enter:Copy codejava -version
3. The output will display the installed Java version information.
4. Checking Java Version Programmatically

If you want to check the Java version programmatically in a Java application, you can use the java.lang.System class. Here’s an example code snippet:

public class JavaVersionChecker {
    public static void main(String[] args) {
        String javaVersion = System.getProperty("java.version");
        System.out.println("Java version: " + javaVersion);
    }
}

Running this code will print the installed Java version.

Checking Java Version in Integrated Development Environments (IDEs)

If you are using an Integrated Development Environment (IDE) for Java development, there are typically built-in features to check the Java version. Here are instructions for checking the Java version in some popular IDEs:

• Eclipse: In Eclipse, click on Help > Eclipse Marketplace. Search for “Java Development Tools” and install the appropriate version. Once installed, you can go to Window > Preferences > Java > Installed JREs to view the installed Java version.
• IntelliJ IDEA: In IntelliJ IDEA, go to File > Project Structure. Under Platform Settings, click on SDKs to see the installed Java versions.
• NetBeans: In NetBeans, go to Tools > Java Platforms to view the installed Java versions.

It’s important to note that these instructions may vary slightly depending on the IDE version you are using.

Checking Java Version on Remote Servers

If you need to check the Java version on a remote server, you can use SSH (Secure Shell) to access the server’s command line interface. Once connected, you can follow the instructions mentioned earlier for checking the Java version using the command line.

Here’s an example command to check the Java version using SSH:

ssh user@hostname java -version

Replace user with your username and hostname with the IP address or domain name of the remote server.

Conclusion

Checking the Java version is a crucial step in Java development and troubleshooting. In this article, we explored various methods to check the Java version on different operating systems, including using the command line, Control Panel, Terminal, and IDEs. We also provided a code snippet for programmatically retrieving the Java version within a Java application. Additionally, we briefly discussed checking the Java version on remote servers using SSH. With the knowledge gained from this article, you can confidently determine the Java version installed on your system and ensure compatibility and smooth functioning of your Java applications.