ajax异步

 

js中获取Ajax实例：

function getAjax() {

   var a = null;

   try {

      a = new ActiveXObject("Msxml2.XMLHTTP");

   }catch (b) {

      try {

        a = new ActiveXObject("Microsoft.XMLHTTP");

      }catch (c) {

        a = null;

      }

   }

   if (!a && typeof XMLHttpRequest != "undefined") {

      a = new XMLHttpRequest;

   }

   return a;

}

 

js中使用异步：

function _selectid(obj){

      var A;

      if(A==null)A=getAjax();

      if (A.readyState != 0 && A.readyState != 4) {

         A.abort();

      }

      if(A){

        var rq =document.getElementById("cxrq").value;

        A.open("GET", "getdata.jsp?xmid="+obj.value+"&cxrq="+rq, true);

        A.onreadystatechange = function () {

           if (A.readyState == 4&& A.responseText) {

               if(A.status==200) {              obj.parentNode.parentNode.childNodes[6].childNodes[0].value=A.responseText;

               }

            }

           };

        A.send(null);

      }

   }

 

 

Jsp页面内容：

<%@ page language="java" pageEncoding="GB2312"%>

<%@ page import="com.victorysoft.ps.util.DAOFactory"%>

<%@ page import="com.victorysoft.ps.sccb.wtsc.dao.WtscDAO"%>

<%@ page import="com.victorysoft.util.DateUtil"%>

<% 

   String xmid = request.getParameter("xmid");

   String rq = request.getParameter("cxrq");  

   WtscDAO dao =DAOFactory.getInstance().getWtscDAO();

   String ps = dao.getNearData(DateUtil.parse(rq),xmid);  

   out.clear();

   out.print(ps);

%>

 

***********************************************************

 

js中使用异步：

function getxm(t){

      var nd;

      var dw;

      if(t.name=="nd"){

        nd=t.value;

        dw=document.getElementById("dw").value;

      }else{

        nd=document.getElementById("nd").value;

        dw=t.value;

      }

      var A = getAjax();

      if (A.readyState != 0 && A.readyState != 4) {

        A.abort();

      }

      if(A){

        A.open("GET", "getxm.jsp?nd="+nd+"&dw="+dw, true);

        A.onreadystatechange = function () {

           if (A.readyState == 4&& A.responseText) {

              if(A.status==200) {

                 var v = eval(A.responseText);

                 var dwSel = document.form1.xm;

                 dwSel.length=0;

                 dwSel[0]=new Option("全部","");

                 for(var i=0;i<v.length;i=i+2){

dwSel[dwSel.length] = new Option(v[i+1],v[i]);

                    if(v[i]=='<%=cycdm%>')

                      dwSel[dwSel.length-1].selected="selected";

                 }

              }

           }

        };

        A.send(null);

      }

   }

Jsp页面内容：

<%@ page language="java" pageEncoding="gb2312"%>

<%@ page import="java.util.List,java.util.Map"%>

<%@ page import="com.victorysoft.ps.util.DAOFactory"%>

<%

   response.setHeader("Pragma","No-cache");

   response.setHeader("Cache-Control","no-cache");

   response.setDateHeader("Expires", 0);

   String nd = request.getParameter("nd");

   String dw = request.getParameter("dw");

   List xmList=DAOFactory.getInstance()

.getCnxmInforDAO().getAllXm(nd,dw);

   String res = "[";

   for(int i=0;i<xmList.size();i++){

      Map map = (Map)xmList.get(i);

      if(i!=0)

   res+=",";

      res+="'"+map.get("XMID")+"','"+map.get("XMJC")+"'";

   }

   res+="]";

   out.clear();

   out.print(res);

%>