mvc 各种返回值

一个例子胜过千言万语，直接上代码

SpringMVC的Controller控制器返回值详解

SpringMVC Controller 返回值几种类型

Spring MVC 更灵活的控制 json 返回（自定义过滤字段）   另1

/**
     *
     * @return Bean
     */
    @RequestMapping("/Test")
    @ResponseBody
    public TestBean  test (){
    log.debug("Test function");
    TestBean testBean=new TestBean();
    testBean.setName("haha");
        return testBean;
    }
    /**
     *
     * @return Bean List
     */
    @RequestMapping("/TestList")
    @ResponseBody
    public List<TestBean>  testList (){
    log.debug("TestList function");
    List<TestBean> testBeanList=new ArrayList<TestBean>();
    TestBean testBean1=new TestBean();
    testBean1.setName("haha");
    TestBean testBean2=new TestBean();
    testBean2.setName("hehe");
    testBeanList.add(testBean1);
    testBeanList.add(testBean2);
        return testBeanList;
    }     

    /**
     *
     * @return JSON Data
     */
    @RequestMapping("/TestJSONObject")
    public void  testReturrnJSONWithoutBean(HttpServletRequest request,HttpServletResponse response) throws IOException{
        log.debug("TestJSONObject function");
        response.setContentType("application/json");
        response.setCharacterEncoding("UTF-8");
        PrintWriter writer=response.getWriter();
        JsonObject jsonObject=new JsonObject();
        jsonObject.addProperty("name","hehe jsonobject");
        writer.println(jsonObject.toString());
        writer.close();
        }  

    /**
     *
     * @return String
     */
    @RequestMapping("/TestReturnPage")
    @ResponseBody
    public String  testReturrnPage(){
        log.debug("TestReturnPage");
            return "/testpage";
        }     

    /**
     * The difference between model and modelandview is just sematic
     * */
    /**
     * @return JSON ModelAndView
     */
    @RequestMapping("/TestReturnModel")
    public String  testReturnModel(Model model){
        log.debug("testReturrnModel");
        model.addAttribute("testmodel", "hello model");
            return "testpage";
        }
    /**
     * The difference between model and modelandview is just sematic
     * */
    /**
     * @return JSON ModelAndView
     */
    @RequestMapping("/TestReturnModelAndView")
    public ModelAndView  testReturnModelAndView(){
        log.debug("testReturrnModel");
        ModelAndView mav = new ModelAndView("testpage");
        mav.addObject("testmodel", "hello test model");
            return mav;
        }     

/**
     * 获取系统显示的菜单
     *
     * @param 无
     * @return 返回JSON字符串，这是经过处理后的结构化树形数据。
     */
    @RequestMapping(value = "/getShowedMenus", produces = "application/json; charset=utf-8")
    @ResponseBody
    public String getShowedMenus() {
        JsonArray menus=new JsonArray();
        try{
            menus=platformMenuService.getMenusForShow();
        }catch(Exception e)
        {
            logger.error(e.toString());
            e.printStackTrace();
        }
        return menus.toString();
    }
    /**
     * 从远程数据中心中注销登录
     * @param request
     * @param response
     * @return 返回逻辑值
     */
    @RequestMapping("/logout")
    @ResponseBody
    private boolean logout(HttpServletRequest request,HttpServletResponse response)
    {
     boolean retVal=false;
     try{  

     }catch(Exception e){
      logger.error(e.toString());
     }
        return retVal;
    }
    /**
     * 本地数据中心登录至远程数据中心。
     * @param datacenterId
     * @return 返回是否登录成功
     */
    @RequestMapping(value="/login",produces = "application/json; charset=utf-8")
    @ResponseBody
    public Boolean login(String dcId,HttpServletRequest request,HttpServletResponse response) {
        logger.info("datacenterId"+dcId);
        dcId="12";
        Boolean retVal=false;
        try{
         DatacatalogDatacenter dc=datacenterService.selectByPrimaryKey(dcId);
String url="http://localhost:8080/"+request.getContextPath()+"/rest/datacatalog/datacenter/server/login?&no=121";
String val=HttpUtils.HttpPost(url);
    retVal=Boolean.parseBoolean(val);
//retObject=new JSONObject(detail);
        }catch(Exception e){
         logger.error(e.toString());
         e.printStackTrace();
        }
        return retVal;
    } 

//使用request转向页面

@RequestMapping("/itemList2")
public void itmeList2(HttpServletRequest request, HttpServletResponse response) throws Exception {
    // 查询商品列表
    List<Items> itemList = itemService.getItemList();
    // 向页面传递参数
    request.setAttribute("itemList", itemList);
    // 如果使用原始的方式做页面跳转，必须给的是jsp的完整路径
    request.getRequestDispatcher("/WEB-INF/jsp/itemList.jsp").forward(request, response);
}

也通过response实现页面重定向：
response.sendRedirect("url")
如：

@RequestMapping("/itemList2")
public void itmeList2(HttpServletRequest request, HttpServletResponse response) throws Exception {
    PrintWriter writer = response.getWriter();
    response.setCharacterEncoding("utf-8");
    response.setContentType("application/json;charset=utf-8");
    writer.write("{\"id\":\"123\"}");

第一种，通过request.setAttribute进行返回。

@RequestMapping(value="/welcomeF")
public String WelcomeF(User user,HttpServletRequest request){
System.out.println(user.toString());
/*通过setAttribute来设置返回*/
request.setAttribute("name", user.getName());
request.setAttribute("password", user.getPassword());
request.setAttribute("password", user.getHobby());
return "welcome";
}

第二种，通过ModelAndView进行返回。

@RequestMapping(value="/welcomeSeven")
public ModelAndView WelcomeSeven(User2 user2){
/*通过ModelAndView来返回数据*/
ModelAndView mav = new ModelAndView("welcome");
mav.addObject("name", user2.getName());
mav.addObject("date", user2.getUdate());
return mav;
}

第三种，通过model对象进行返回。

@RequestMapping(value="/welcomeEight")
public String WelcomeEight(User2 user2,Model model){
/*通过Model对象来返回数据*/
model.addAttribute("name", user2.getName());
model.addAttribute("date", user2.getUdate());
return "welcome";
}

第四种，通过Map对象进行返回。

@RequestMapping(value="/welcomeNine")
public String WelcomeNine(User2 user2,Map map){
/*通过Model对象来返回数据*/
map.put("name", user2.getName());
map.put("date", user2.getUdate());
return "welcome";
}

spring mvc返回json数据，只需要返回一个java bean对象就行，只要这个java bean 对象实现了序列化serializeable

    @RequestMapping(value = { "/actor_details" }, method = { RequestMethod.POST })
    @ResponseBody
    public ResultObject actorDetails(@RequestBody ActorDetailsRequest req) {
        logger.debug("查看{}主播信息", req.getAid());
        if (req.getAid() == null || req.getAid().equals("null")
                || req.getAid().equals("")) {
            return new ResultObject(ResultCode.NULL_PARAM);
        }
        ActorAndUser result = actorServiceImpl.queryActorData(req.getAid());
        return new ResultObject(result);
    }

ModelAndView

   @RequestMapping(method=RequestMethod.GET)
    public ModelAndView index(){
        ModelAndView modelAndView = new ModelAndView("/user/index");
        modelAndView.addObject("xxx", "xxx");
        return modelAndView;
    }

@RequestMapping(method=RequestMethod.GET)
    public ModelAndView index(){
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.addObject("xxx", "xxx");
        modelAndView.setViewName("/user/index");
        return modelAndView;
    }

Map

响应的view应该也是该请求的view。等同于void返回。
@RequestMapping(method=RequestMethod.GET)
    public Map<String, String> index(){
        Map<String, String> map = new HashMap<String, String>();
        map.put("1", "1");
        //map.put相当于request.setAttribute方法
        return map;
    }

@RequestMapping("/demo2/show")
    publicMap<String, String> getMap() {
        Map<String, String> map = newHashMap<String, String>();
        map.put("key1", "value-1");
        map.put("key2", "value-2");
        returnmap;
    }

在jsp页面中可直通过${key1}获得到值, map.put()相当于request.setAttribute方法。
写例子时发现，key值包括 - . 时会有问题.

String

对于String的返回类型，笔者是配合Model来使用的；
@RequestMapping(method = RequestMethod.GET)2
    public String index(Model model) {
        String retVal = "user/index";
        List<User> users = userService.getUsers();
        model.addAttribute("users", users);
        return retVal;
    }

或者通过配合@ResponseBody来将内容或者对象作为HTTP响应正文返回（适合做即时校验）；

    @RequestMapping(value = "/valid", method = RequestMethod.GET)
    public @ResponseBody
    String valid(@RequestParam(value = "userId", required = false) Integer userId,@RequestParam(value = "logName") String strLogName) {
    return String.valueOf(!userService.isLogNameExist(strLogName, userId));
    }

具体参考：https://blog.csdn.net/u011001084/article/details/52846791  太长了，没整理

@RequestMapping(value=”twoB.do”)
public void twoBCode(HttpServletRequest request,HttpServletResponse response) {
response.setContentType(“type=text/html;charset=UTF-8”);
String s = “一堆字符串……”;
response.getWriter().write(s);
return;
} 

上面的太low，用下面的比较好
@RequestMapping(value=”getJosn.do”, produces=”text/html;charset=UTF-8”) 
@ResponseBody 
public String getTabJson(){ 
String json = “{“无主题”:”jjjjj”}”; 
return json; 
}