How to detect OS in Java

This article shows a handy Java class that uses System.getProperty("os.name") to detect which type of operating system (OS) you are using now.

1. Detect OS (Original Version)

This code can detect Windows, Mac, Unix, and Solaris.

package com.mkyong.system;

public class OSValidator {

    private static String OS = System.getProperty("os.name").toLowerCase();

    public static void main(String[] args) {

        System.out.println("os.name: " + OS);

        if (isWindows()) {
            System.out.println("This is Windows");
        } else if (isMac()) {
            System.out.println("This is Mac");
        } else if (isUnix()) {
            System.out.println("This is Unix or Linux");
        } else if (isSolaris()) {
            System.out.println("This is Solaris");
        } else {
            System.out.println("Your OS is not support!!");
        }
    }

    public static boolean isWindows() {
        return (OS.indexOf("win") >= 0);
    }

    public static boolean isMac() {
        return (OS.indexOf("mac") >= 0);
    }

    public static boolean isUnix() {
        return (OS.indexOf("nix") >= 0
                || OS.indexOf("nux") >= 0
                || OS.indexOf("aix") > 0);
    }

    public static boolean isSolaris() {
        return (OS.indexOf("sunos") >= 0);
    }

}

Output, run on Windows 10.

os.name: windows 10
This is Windows

2. Detect OS (Enhanced Version)

Since the operating system will remain the same for the running Java app, we can increase the performance by moving the OS checking to static fields; The static ensures the OS.indexOf checking runs once only.

package com.mkyong.system;

public class OSValidator {

    private static String OS = System.getProperty("os.name").toLowerCase();
    public static boolean IS_WINDOWS = (OS.indexOf("win") >= 0);
    public static boolean IS_MAC = (OS.indexOf("mac") >= 0);
    public static boolean IS_UNIX = (OS.indexOf("nix") >= 0 || OS.indexOf("nux") >= 0 || OS.indexOf("aix") > 0);
    public static boolean IS_SOLARIS = (OS.indexOf("sunos") >= 0);

    public static void main(String[] args) {

        System.out.println("os.name: " + OS);

        if (IS_WINDOWS) {
            System.out.println("This is Windows");
        } else if (IS_MAC) {
            System.out.println("This is Mac");
        } else if (IS_UNIX) {
            System.out.println("This is Unix or Linux");
        } else if (IS_SOLARIS) {
            System.out.println("This is Solaris");
        } else {
            System.out.println("Your OS is not support!!");
        }
    }

}

Download Source Code

References

• System JavaDoc
• Wikipedia – Operating system