Java从后台重定向（redirect）到另一个项目的方法

本文摘自：http://blog.youkuaiyun.com/aqsunkai/article/details/51374670

首先感谢博主的总结，让我成功解决了自己的问题，想转发呢 但是因为转发不成所以就copy啦~望见谅！

（1）通过ModelAndView跳转

@RequestMapping("alipayforward")  
    public ModelAndView alipayforward(HttpServletRequest req, HttpServletResponse resp) throws Exception {  
        String contNo =req.getParameter("contNo");  
        logger.info("访问/downloadRequestElecCont.action");  
        String url = "redirect:http://baidu.com/downloadRequestElecCont.action?contNo="+contNo;   
        return new ModelAndView(url);  
    }  

（2）通过HttpServletResponse跳转

@RequestMapping("alipayforward/{contNo}")  
    public void alipayforward(@PathVariable("contNo") String contNo, HttpServletRequest req, HttpServletResponse resp) throws Exception {  
        //String contNo =req.getParameter("contNo"); //保单号  
        logger.info("访问/downloadRequestElecCont.action");  
        resp.sendRedirect("http://baidu.com/downloadRequestElecCont.action?contNo="+contNo);  
    }  

（3）通过redirect返回String类型跳转，注意这种方法不允许Spring控制器用@RestController注解，

因为@RestController相当于类中的所有方法都标注了@ResponseBody，这些方法不会返回一个视图，而是返回一个json对象，

这样的话只是在页面上打印出字符串，而不跳转。控制器用@Controller注解即可

@RequestMapping("alipayforward")  
    public String alipayforward(@RequestParam("contNo") String contNo, HttpServletRequest req, HttpServletResponse resp) throws Exception {  
        //String contNo =req.getParameter("contNo"); //保单号  
        logger.info("访问/downloadRequestElecCont.action");  
        return "redirect:http://baidu.com/downloadRequestElecCont.action?contNo="+contNo;  
    }  

下面是关于传参问题

重定向传参为get方式，如果传参数较多，可以封装到map或modelMap中

@RequestMapping(params = "action=alipayforward")  
    public String alipayforward(Map modelMap){  
        modelMap.put("userName", "呵呵");  
        modelMap.put("password", "123456");  
        modelMap.put("age", "25");  
        return "redirect:http://localhost:8088/era/user/alipayforward4?modelMap="+modelMap;  
    } 

另一个项目用实体类对象接收

@RequestMapping("alipayforward4")  
    public void alipayforward4(User user, HttpServletRequest req) throws Exception {  
        System.out.println(user.getPassword());  
        String modelMap = req.getParameter("modelMap");  
        System.out.println(modelMap);  
    }