在學習 Spring Mvc 過程當中,有必要來先了解幾個關鍵參數:html
@Controller:java
在類上註解,則此類將編程一個控制器,在項目啓動 Spring 將自動掃描此類,並進行對應URL路由映射。web
@Controller public class UserAction { }
@RequestMapping編程
指定URL映射路徑,若是在控制器上配置 RequestMapping ,具體請求方法也配置路徑則映射的路徑爲二者路徑的疊加 經常使用映射如:RequestMapping("url.html")json
配置映射路徑:cookie
@Controller public class UserAction { @RequestMapping(value = "/get_alluser.html") public ModelAndView GetAllUser(String Id) { } }
以上配置映射app
http://***:8080:web1/get_alluser.html:ide
如在 @Controller添加 @RequestMapping(value = "/user"),則映射路徑變成post
http://***:8080:web1/user/get_alluser.html學習
@ResponseBody
將註解方法對應的字符串直接返回
@RequestParam
自動映射URL對應的參數到Action上面的數值,RequestParam 默認爲必填參數。
@PathVariable
獲取@RequestMapping 配置指定格式的URL映射參數
/* * 直接輸出 HTML,或JSON 字符串 * 請求路徑: * /web1/urlinfo/getcontent.html?key=rhythmk * /web1/urlinfo/getcontent.json?key=rhythmk * */ @ResponseBody @RequestMapping(value = "/getcontent.**") public String GetContent( @RequestParam("key") String key, @RequestParam(value = "key2", required = false, defaultValue = "defaultValue") String key2) { System.out.println("getcontent 被調用"); String result = "直接返回內容 - key:" + key + ",key2:" + key2; System.out.println(result); return result; }
/* * RequestMapping 支持 Ant 風格的URL配置 : * 請求路徑: * /urlinfo/geturlant/config.html?key=adddd */ @ResponseBody @RequestMapping(value = "/geturlant/**.html") public String getUrlAnt(HttpServletRequest request) { String result = "?後面的參數爲:" + request.getQueryString(); return result; }
/* * 配置指定格式的URL,映射到對應的參數 * 請求路徑:/web1/urlinfo/geturlparam/12_123.html * * */ @RequestMapping(value = "/geturlparam/{id}_{menuId}.html") public ModelAndView getUrlParam(@PathVariable("id") String id, @PathVariable("menuId") String menuId) { ModelAndView mode = new ModelAndView(ShowMsg); mode.addObject("msg", "獲取到的Id:" + id + ",menuId:" + menuId); return mode; }
/* * 只接收Post 請求 */ @ResponseBody @RequestMapping(value = "/posturl.html", method = RequestMethod.POST) public String UrlMethod(@RequestParam String id) { return "只能是Post請求,獲取到的Id:" + id; }
/* * 寫入 cookie * */ @RequestMapping("/writecookies.html") public ModelAndView writeCookies(@RequestParam String value, HttpServletResponse response) { response.addCookie(new Cookie("key", value)); ModelAndView mode = new ModelAndView(ShowMsg); mode.addObject("msg", "cookies 寫入成功"); return mode ; }
/* * 經過 @CookieValue 獲取對應的key的值 * */ @RequestMapping("/getcookies.html") public ModelAndView getCookie(@CookieValue("key") String cookvalue) { ModelAndView mode = new ModelAndView(ShowMsg); mode.addObject("msg", "cookies=" + cookvalue); return mode; }
/* * 將 Servlet Api 做爲參數傳入 * 能夠在action中直接使用 HttpServletResponse,HttpServletRequest * */ @RequestMapping("/servlet.html") public String Servlet1(HttpServletResponse response, HttpServletRequest request) { Boolean result = (request != null && response != null); ModelAndView mode = new ModelAndView(); mode.addObject("msg", "result=" + result.toString()); return ShowMsg; }
/* * 根據URL傳入的參數實例化對象 * * 如: http://127.0.0.1:8080/web1/urlinfo/getobject.html?UserId=1&UserName=ad * */ @RequestMapping("getobject.html") public ModelAndView getObject(UserInfo user) { String result = "用戶ID:" + user.getUserId().toString() + ",用戶名:" + user.getUserName().toString(); ModelAndView mode = new ModelAndView(ShowMsg); mode.addObject("msg", "result=" + result.toString()); return mode; }
實現頁面跳轉:
/* * 實現頁面跳轉 * /web1/urlinfo/redirectpage.html * */ @RequestMapping("/redirectpage.html") public String RedirectPage() { return "redirect:getcookies.html?r=10"; }
直接回傳JSON
請求的URL地址必定是以.json結尾,不然異常
Failed to load resource: the server responded with a status of 406 (Not Acceptable) : The resource identified by this request is only capable of generating responses with characteristics not acceptable according to the request "accept" headers ()
回傳實體:
@JsonSerialize(include = JsonSerialize.Inclusion.NON_NULL) public class UserInfo { private Integer UserId; public Integer getUserId() { return UserId; } public void setUserId(Integer userId) { UserId = userId; } public String getUserName() { return UserName; } public void setUserName(String userName) { UserName = userName; } private String UserName; }
回傳 action
@ResponseBody @RequestMapping("/getuser.json") public UserInfo GetUser() { System.out.println("getuser"); UserInfo model=new UserInfo(); model.setUserId(100); model.setUserName("王坤"); return model; }
請求:
/web1/urlinfo/getuser.json
輸出:
{"userId":100,"userName":"王坤"}