Spring MVC 学习 之 - URL参数传递详解

时间:2022-02-26 23:42:39

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。

?
1
2
3
@Controller
 
public 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:

?
1
2
3
4
5
6
7
8
@Controller
public 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

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
/*
  *  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;
 }
?
1
2
3
4
5
6
7
8
9
10
11
/*
  * 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;
 }
?
1
2
3
4
5
6
7
8
9
10
11
12
13
/*
  * 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;
 }
?
1
2
3
4
5
6
7
8
/*
 * 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;
}
?
1
2
3
4
5
6
7
8
9
10
11
12
/*
 *  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 ;
}
?
1
2
3
4
5
6
7
8
9
/*
  * 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;
}
?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
/*
 * 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;
 
}
?
1
2
3
4
5
6
7
8
9
10
11
12
13
/*
 *  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:

?
1
2
3
4
5
6
7
8
9
10
/*
 * 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:
 

?
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
@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 

?
1
2
3
4
5
6
7
8
9
10
@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:

?
1
{"userId":100,"userName":"王坤"}

 以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。