How to detect Operating System using Java code

If you have a Java Application that is supposed to run on various operating system (Windows, macOS, Linux etc) it becomes very important to know which underlying operating system is the code executing to set options like - directory structure, file system, end of line encoding (CL, RF, CLRF) etc,

Java code to detect Operating System (OS):

/**
 * 
 * Detect Java OS
 * 
 */
public class Example {

    public static void main(String[] args) {

        String os = getOperatingSystemDetails();

        if(os.contains("Windows")) {
            System.out.println("Your Operating System is - Windows");
        } else if (os.contains("Mac OS X")) {
            System.out.println("Your Operating System is - macOS");
        } else if  (os.contains("Linux")) {
            System.out.println("Your Operating System is - Linux"); 
        } else {
            System.out.println("Your Operating System is " + os);
        }

    }

    /**
     * This Method returns the underlying OS where
     * the Java code run.
     * 
     * @return the Operating System name as a String
     */
    public static String getOperatingSystemDetails() {
        return System.getProperty("os.name");

    }

}

Your Operating System is - macOS