ajax案例

JSP页面：
//动态获取列的信息
function tankToWeb() {
var storeIndex=document.getElementByI('storeIndex').value;
if(storeIndex=="") return false;
var myAjax = new Ajax.Request('archiveTankGrid.do?service=tankToWeb',
{
method: 'post',parameters: 'wareHouse='storeIndex,
onComplete: function(response) {
   var ret = response.responseText;

   if(ret=="error"){
        alert("选择出错！");
        return false;
    }else
{
     ret="<select name='archiveTankLineVo.tankIndex' style='width:100px'><option value=''>--请选择--</option>"+ret;
                         ret=ret+"</select>";
document.getElementById("testid").innerHTML=ret;
       return true;
}
   }
});
}

action 中service=tankToWeb 调用查询方法
//2.根据机构、库房ID获取档案柜列
    private void tankToWeb(){
        String returnName="";
        HttpServletRequest request = ServletActionContext.getRequest();
        HttpServletResponse response = ServletActionContext.getResponse();
        response.setCharacterEncoding("GBK");
        response.setContentType("text/html;charset=GBK");
        String wareHouse=request.getParameter("wareHouse");
        String orgId=request.getParameter("orgId");
        String gtType=Util.getParameterValue(request.getParameter("gtType"));
        try {
            PrintWriter out = response.getWriter();
            returnName= getArchiveTank(orgId,wareHouse,gtType);
            out.println(returnName);
            out.close();
        } catch (Exception e) {
            try {
                PrintWriter out = response.getWriter();
                System.out.println("tankToWeb出错！");
                out.println("error");
                out.close();
            } catch (IOException e1) {
                e1.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
            }
        }
     }
public String getArchiveTank(String orgId,String storeIndex,String gtType){
        //String hql="select tankIndex,tankName from T_ArchiveTank where storeIndex='"+storeIndex+"' order by tankIndex";
         String hql = "select distinct tankIndex,tankName from T_ArchiveTankGrid where  orgId='"+orgId+"' and storeIndex='"+storeIndex+"' order by tankIndex";
        List list = archiveTankService.findArchiveTankByStoreIndex(hql);

        String retStr="";
        Iterator it=list.iterator();

        if("0".equals(gtType)){
            while(it.hasNext()){
               Object[] obj=(Object[])it.next();
               retStr+="<option value="+obj[0].toString()+">"+obj[0].toString()+"</option>";
            }
        }else{
            while(it.hasNext()){
               Object[] obj=(Object[])it.next();
               retStr+="<option value="+obj[0].toString()+">"+obj[1].toString()+"</option>";
            }
        }

        return retStr;
     }