标签：style blog http color java os io for
对于某些Controller的处理方法，当返回值为String类型时，返回的结果中可能含有forward或redirect前缀；
如：
1 @Controller 2 @RequestMapping("/user") 3 public class UserController { 4 @RequestMapping("/forward") 5 public String replyWithForward(HttpServletRequest request, String userId){ 6 request.setAttribute("userid", userId); 7 8 System.out.println("userId =" +userId); 9 10 return "forward:hello"; 11 } 12 13 @RequestMapping("/redirect") 14 public String replyWithRedirect(HttpServletRequest request, String userId){ 15 request.setAttribute("userid", userId); 16 17 System.out.println("userId = "+userId); 18 19 return "redirect:hello"; 20 } 21 }
测试页面hello.jsp：
1 <%@ page language="java" contentType="text/html; charset=UTF-8" 2 pageEncoding="UTF-8"%> 3 <% 4 String userId = (String)request.getAttribute("userid"); 5 System.out.println("获取到的userId为："+userId); 6 %> 7 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 8 <html> 9 <head> 10 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 11 <title>测试页面</title> 12 </head> 13 <body> 14 hello, <%= userId %>; 15 </body> 16 </html>
当路径为 http://localhost:8080/crazysnailweb/user/forward?userId=123时，浏览器中的URL不会发生变化，且页面输出：
当路径为http://localhost:8080/crazysnailweb/user/redirect?userId=123 时，浏览器中URL变为http://localhost:8080/crazysnailweb/user/hello，且页面输出：
注：redirect会让浏览器发起一个新的请求，因而原来request对象中的参数丢失；而forward所到的目标地址位于当前请求中，request中的参数不会丢失；
forward:hello 与 redirect:hello的区别,布布扣,bubuko.com
forward:hello 与 redirect:hello的区别
标签：style blog http color java os io for
原文地址：http://www.cnblogs.com/-crazysnail/p/3923108.html
