前台页面：
function selectChange(id){
?jQuery.get("managercheck_getCarListByType.do?carType.id="+id,function(data){
?if(data!="nodata"){
?//var json=[{'id':'33','carCode':'ddd'},{'id':'33','carCode':'ddd'}];
?var json=eval(data);
?processData(json);
?}
?else processData(null);
?});
?}
function processData(json){
?var select=document.getElementById("carSelect");
?if(select.options.length > 1){
? var a = select.options.length;
?? while(a > 1){
??? select.removeChild(select.options[--a]);
???? }
???}
?? if(json!= null){
???for(var i = 0;i < json.length;i++){
??? select.options.add(new Option(json[i].carCode,json[i].carId));
?????? }
???? }
??}
?
后台：
?public String getCarListByType(){
??if(carType!=null&&carType.getId()!=null){
??carList=carService.findCarsByType(carType);
??System.out.println(carList.size());
??HttpServletResponse response = ServletActionContext.getResponse();
??
??try {
???PrintWriter out = response.getWriter();
???StringBuffer sb=new StringBuffer();
???sb.append("[");
???if(carList!=null&&carList.size() > 0){
????response.setContentType("text;charset=gbk");
????for(Car car : carList){
?????sb.append("{'carId':'"+car.getId()+"',"+"'carCode':'"+car.getCarCode()+"'},");
????}
????sb.replace(sb.length()-1, sb.length(), "");
????sb.append("]");
????out.println(sb.toString());
???}
???else {
????response.setContentType("text;charset=gbk");
????out.print("nodata");
???}
??} catch (IOException e) {
???// TODO Auto-generated catch block
???e.printStackTrace();
??}
??}
??return null;
?}