Spring MVC 學(xué)習(xí) 之 - URL參數(shù)傳遞詳解

2019-11-26 13:18:08

字體：大中小

供稿：網(wǎng)友

在學(xué)習(xí) Spring Mvc 過程中，有必要來先了解幾個關(guān)鍵參數(shù)：

@Controller：

在類上注解，則此類將編程一個控制器，在項目啟動 Spring 將自動掃描此類，并進行對應(yīng)URL路由映射。

@Controllerpublic class UserAction{ }

@RequestMapping

指定URL映射路徑，如果在控制器上配置 RequestMapping ，具體請求方法也配置路徑則映射的路徑為兩者路徑的疊加常用映射如:RequestMapping("url.html")

配置映射路徑：

@Controllerpublic class UserAction {  @RequestMapping(value = "/get_alluser.html")  public ModelAndView GetAllUser(String Id)  {  }}

以上配置映射

http://***:8080:web1/get_alluser.html：

如在 @Controller添加 @RequestMapping(value = "/user"),則映射路徑變成

http://***:8080:web1/user/get_alluser.html

@ResponseBody

將注解方法對應(yīng)的字符串直接返回

@RequestParam

自動映射URL對應(yīng)的參數(shù)到Action上面的數(shù)值，RequestParam 默認(rèn)為必填參數(shù)。

@PathVariable

獲取@RequestMapping 配置指定格式的URL映射參數(shù)

 /*   *  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(diào)用");    String result = "直接返回內(nèi)容 - key:" + key + ",key2:" + key2;    System.out.println(result);    return result;  }

 /*   * RequestMapping 支持 Ant 風(fēng)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 = "?后面的參數(shù)為：" + request.getQueryString();    return result;  }

 /*   * 配置指定格式的URL，映射到對應(yīng)的參數(shù)   *  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 ;  }

  /*    * 通過 @CookieValue 獲取對應(yīng)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 作為參數(shù)傳入    *  可以在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(jù)URL傳入的參數(shù)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(xiàn)頁面跳轉(zhuǎn)：

  /*    * 實現(xiàn)頁面跳轉(zhuǎn)   * /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地址一定是以.json結(jié)尾，否則異常

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：