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Spring MVC 学习 之 - URL参数传递详解

程序员文章站 2024-03-08 14:15:40
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...

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。

@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:

@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

 /*
   *  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:

 {"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。