ajax请求后台详解

AJAX 是一种在无需重新加载整个网页的情况下,能够更新部分网页的技术。

什么是 AJAX ?

AJAX = 异步 JavaScript 和 XML。

AJAX 是一种用于创建快速动态网页的技术。

通过在后台与服务器进行少量数据交换,AJAX 可以使网页实现异步更新。这意味着可以在不重新加载整个网页的情况下,对网页的某部分进行更新。

传统的网页(不使用 AJAX)如果需要更新内容,必需重载整个网页面。

有很多使用 AJAX 的应用程序案例:新浪微博、Google 地图、开心网等等。

前端ajax与后端Spring MVC控制器有以下五种数据交互方式

方式一  通过URL传参

通过URL挂接参数,如/auth/getUser?userid='6'

服务器端方法可编写为:getUser(String userid),也可新增其他参数如HttpSession, HttpServletRequest,HttpServletResponse,Mode,ModelAndView等。

 

方式二  单值传参

前台调用如:

ajaxPost("/base/user/exchangeSort",{"id":rid,"otherid":otherid},function(data,status){

                                       xxxxxx

                        xxxxxx

                             });

 

服务器端为:

public String exchangeSort(String id, String otherid)

 

方式三  对象传参

前台调用如:

  var org={id:id};

    ajaxPost("/base/org/getOrgById", org,function(data,textStatus){

                  xxxx

                  xxxx

     }); 

服务器端为

public Org getOrgById(Org org)

 

 

方式四  对象序列化传参

前台调用如:

var ueser={id:rowId};

var data=ajaxPost("/base/user/findById",{"userObj":JSON.stringify(user)},null);

或者

var ueser={ };//创建对象

user["id"]=id;

user["name"]=$("#name").val();

user["dept"]={};//外键对象

user["dept"]["id"]=$("#deptid").val();

ajaxPost("/base/user/addUser",{"userObj":JSON.stringify(user)},function(data){xxxx;xxxxx;});

 

服务器端为:

      @RequestMapping("/findById")

      @ResponseBody

      public UserInfo findById(String userObj) {

       //使用fastJSON

             UserInfo user = JSON.parseObject(userObj, UserInfo.class);

             user = (UserInfo) userService.findById(UserInfo.class, user.getId());

             return user;

      }

 

方式五  列表传参

前台代码如:

               var objList = new Array();

                            grid.forEachRow(function(rId) {

                                  var index = grid.getRowIndex(rId);

                                  var obj = {};

                                   obj["id"] = rId;

                                   obj["user"] = {};

                                   obj["user"]["id"] = $("#userId").val();

                    //不推荐这样的写法

                                   //obj["kinShip"] = grid.cells(rId, 1).getValue();

                                   //obj["name"] = grid.cells(rId, 2).getValue();

                   obj["kinShip"]=grid.cells(rId,grid. getColIndexById ("columnName")).getValue();

obj["name"]=grid.cells(rId,grid.getColIndexById("name")).getValue();

                                  if(grid.cells(rId, 3).getValue()!=null && grid.cells(rId, 3).getValue()!="") {

                                         var str = grid.cells(rId, 3).getValue().split("-");

                                         var day = parseFloat(str[2]);

                                         var month = parseFloat(str[1])-1;

                                         var year = parseInt(str[0]);

                                         var date=new Date();

                                          date.setFullYear(year, month, day);

                                          obj["birth"] = date;

                                   }else {

                                          obj["birth"] ="";

                                   }

                                   obj["politicalStatus"]  = grid.cells(rId, 4).getValue();

                                   obj["workUnit"] = grid.cells(rId, 5).getValue();

                                  if (grid.cells(rId, 6).isChecked())

                                          obj["isContact"] ="1";

                                  else

                                          obj["isContact"] ="0";

                                   obj["phone"] = grid.cells(rId, 7).getValue();

                                   obj["remark"] = grid.cells(rId, 8).getValue();

                                   obj["sort"] = index;

                                   objList.push(obj);

                            });

                           

                            ajaxPost("/base/user/addUpdateUserHomeList", {

                                  "userHomeList" : JSON.stringify(objList),

                                  "userId" : $("#userId").val()

                            },function(data, status) {

                                   xxxxx

                            });

 

服务器端:

  @RequestMapping("/addUpdateUserHomeList")

       @ResponseBody   

       public String addUpdateUserHomeList(String userHomeList, String userId) {

             List<UserHome> userHomes = JSON

                           .parseArray(userHomeList, UserHome.class);//fastJSON

              if (userHomes != null && userHomes.size() > 0) {

                     try {

                            userService.addUpdateUserHomeList(userHomes, userId);

                     } catch (Exception e) {

                            e.printStackTrace();

                     }

              }

              return "200";

       }

 附上ajaxPost代码:

 function ajaxPost(url,dataParam,callback){
     var retData=null;
     $.ajax({ 
         type: "post",
         url: url, 
         data: dataParam,
         dataType: "json",  
         success: function (data,status) {
            // alert(data);
             retData=data;
             if(callback!=null&&callback!=""&&callback!=undefined)
                 callback(data,status); 
         },
         error: function (err,err1,err2) {     
             alertMsg.error("调用方法发生异常:"+JSON.stringify(err)+"err1"+ JSON.stringify(err1)+"err2:"+JSON.stringify(err2));
         }  
 });       
      return retData;
 }

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转载自www.cnblogs.com/lee24789229/p/9216860.html