springMVC中的redirect和forward跳轉

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class Login{
	
        /**轉發**/
	@RequestMapping("/login.do")
	public String login(HttpServletRequest request,HttpServletResponse  response){
		request.setAttribute("message", "hello");
		return "forward:/index.do";  //forward在跳轉後可以取到message值
	}
	@RequestMapping("/index.do")
	public String index(HttpServletRequest request,HttpServletResponse response){
		return "welcome";
	}
	
	/**重定向**/
	@RequestMapping("/logout.do")
	public String logout(HttpServletRequest request,HttpServletResponse  response){
		request.setAttribute("message", "hello");
		return "redirect:/register.do";  //redirect在跳轉後無法取到message值
	}
	@RequestMapping("/register.do")
	public String register(HttpServletRequest request,HttpServletResponse  response){
		return "register";
	}
}

另外forward跳轉後地址欄URL不會改變 而redirect會改變