Spring MVC 学习之 - URL参数传递详解

2024-07-13 10:02:49

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在学习 Spring Mvc 过程中，有必要来先了解几个关键参数：

@Controller：

在类上注解，则此类将编程一个控制器，在项目启动 Spring 将自动扫描此类，并进行对应URL路由映射。

@Controllerpublic class UserAction{ }

@RequestMapping

指定URL映射路径，如果在控制器上配置 RequestMapping ，具体请求方法也配置路径则映射的路径为两者路径的叠加常用映射如:RequestMapping("url.html")

配置映射路径：

@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"),则映射路径变成

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

@ResponseBody

将注解方法对应的字符串直接返回

@RequestParam

自动映射URL对应的参数到Action上面的数值，RequestParam 默认为必填参数。

@PathVariable

获取@RequestMapping 配置指定格式的URL映射参数

 /*   *  直接输出 HTML，或JSON 字符串   *  请求路径:   *    /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 被调用");    String result = "直接返回内容 - key:" + key + ",key2:" + key2;    System.out.println(result);    return result;  }

 /*   * RequestMapping 支持 Ant 风格的URL配置 ：   * 请求路径：   *   /urlinfo/geturlant/config.html?key=adddd   */  @ResponseBody  @RequestMapping(value = "/geturlant/**.html")  public String getUrlAnt(HttpServletRequest request) {    String result = "?后面的参数为：" + request.getQueryString();    return result;  }

 /*   * 配置指定格式的URL，映射到对应的参数   *  请求路径：/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", "获取到的Id:" + id + ",menuId:" + menuId);    return mode;  }

  /*   * 只接收Post 请求   */  @ResponseBody  @RequestMapping(value = "/posturl.html", method = RequestMethod.POST)  public String UrlMethod(@RequestParam String id) {    return "只能是Post请求,获取到的Id:" + id;  }

  /*   *  写入 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 写入成功");    return mode ;  }

  /*    * 通过 @CookieValue 获取对应的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;  }

  /*    * 将 Servlet Api 作为参数传入    *  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;  }

  /*   *  根据URL传入的参数实例化对象   *     *  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 = "用户ID：" + user.getUserId().toString() + ",用户名:"        + user.getUserName().toString();    ModelAndView mode = new ModelAndView(ShowMsg);    mode.addObject("msg", "result=" + result.toString());    return mode;  }

实现页面跳转：

  /*    * 实现页面跳转   * /web1/urlinfo/redirectpage.html   * */  @RequestMapping("/redirectpage.html")  public String RedirectPage()  {    return "redirect:getcookies.html?r=10";           }

直接回传JSON

请求的URL地址一定是以.json结尾，否则异常

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 ()

回传实体：

@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;      }

回传 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;  }

请求：

/web1/urlinfo/getuser.json

输出：