title: What is the use of token tag in Struts2 and how does it work?
body: <p>I came across this <code>&lt;s:token /&gt;</code> tag and it is enclosed in a <code>&lt;s:form&gt;&lt;/s:form&gt;</code> tag in a JSP Page. 
  Some other StackOverflow link discusses its usage in maintaining session and prevention of double submission of forms. What exactly is the use of this tag? If it prevents double submission of form then what happens when I submit form and how does it prevent it? </p>