public class OSValidator {
	public static boolean isWindows() {
		String os = System.getProperty("os.name").toLowerCase();
		// windows
		return (os.indexOf("win") >= 0);
	}
 
	public static boolean isMac() {
		String os = System.getProperty("os.name").toLowerCase();
		// Mac
		return (os.indexOf("mac") >= 0);
	}
 
	public static boolean isUnix() {
		String os = System.getProperty("os.name").toLowerCase();
		// linux or unix
		return (os.indexOf("nix") >= 0 || os.indexOf("nux") >= 0);
	}
 
	public static boolean isSolaris() {
		String os = System.getProperty("os.name").toLowerCase();
		// Solaris
		return (os.indexOf("sunos") >= 0);
	}
}

Check which operating system the program is running. The program explains itself.

Operational System Validator

Java