How to check whether radiobutton is selected or not

Webdriver driver=new FirefoxDriver();

driver.get("https://www.cleartrip.com/");

WebElement radio=driver.findElementBy.id("OneWay"));

boolean selected=radio.isselected();

if(selected==true){

System.out.print("already selected");

}

else{

System.out.print("not selected");

radio.click();

}