#表单验证token#

TokenUtil.java

//token.servlet→jsp→servlet→jsp结果页

public class TokenUtil {

  public static void createToken(HttpServletRequest request,HttpServletResponse response){
		
		UUID uuid = UUID.randomUUID();
		String token = uuid.toString();
		request.getSession().setAttribute("session_token",token);
		request.setAttribute("request_token", token);
		
	}
	
	public static boolean validateToken(HttpServletRequest request,HttpServletResponse response){
		
		String req_token = request.getParameter("token");
		String se_token=(String) request.getSession().getAttribute("session_token");
		
		if(req_token==null || se_token==null || !req_token.equals(se_token)){
//			重复提交
			return false;
		}else{
//			提交成功
			System.out.println("扣钱成功");
//			删除session中的token
			request.getSession().removeAttribute("session_token");
			return true;
		}
	}
}