SpringMVC - 转到空白页面/错误页面 401,500 / Redirect Page

in MVC controller, for example

TestController extends MultiActionController

1. 转到空白页面

public ModelAndView testMVC(HttpServletRequest req,HttpServletResponse res) throws Exception {		
		return null;
}

2. 转到空白页面,并打印字符

public ModelAndView testMVC(HttpServletRequest req,HttpServletResponse res) throws Exception {		
		res.getOutputStream().write(new String("testString").getBytes());
		return null;
}

3. 转到系统错误页面
3.1 forward to one jsp and set the HTTP_STATUS in jsp file :

<%
response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
%>

3.2 set the HTTP_STATUS in MVC Controller.

public ModelAndView testMVC(HttpServletRequest req,HttpServletResponse res) throws Exception {		
		res.setStatus(401);
		return null;
}

4. Redirect in Spring MVC

public ModelAndView testMVC(HttpServletRequest req,HttpServletResponse res) throws Exception {		
		String view = "redirect:"+redirectPath; -- redirectPaht must including the "http://"
			return new ModelAndView(view, model);
}