<headless-server>true</headless-server>

validator 부분 태그
<mx:StringValidator id="stringValidator" property="text" minLength="1" required="true" requiredFieldError="필수 기재 항목입니다."/>

//최종 validation 체크 및 업로드
private function setRegAppl(event:MouseEvent):void {

private function download():void {
    if (tx_fileLogicNm.text == "등록된 파일이 없습니다."){
        tx_fileLogicNm.buttonMode = false;
    }else{
        tx_fileLogicNm.buttonMode = true;
        if(!fileRef) {
            fileRef = new FileReference();
        }
        configureListeners(fileRef);

        var filePhysiclNm:String = contentData.filePhysiclNm;
        var fileLogicNm:String = contentData.fileLogicNm;
        var variables:URLVariables = new URLVariables();
        var urlRequest:URLRequest = new URLRequest(UrlUtil.getUrlRoot("JAVA SERVLET URL"));
        variables.filePhysiclNm = filePhysiclNm;
        variables.uploadPath    = FileCont.FILE_UPLOAD_PATH;
        urlRequest.method = URLRequestMethod.POST;
        urlRequest.data = variables;
        fileRef.download(urlRequest, fileLogicNm);      
    } 
}

private function configureListeners(dispatcher:IEventDispatcher):void {
    //dispatcher.addEventListener(Event.COMPLETE, completeHandler);

- upload -

        try {
            boolean isMultipart = ServletFileUpload.isMultipartContent(request);
           
            if (isMultipart) {
                FileItemFactory factory = new DiskFileItemFactory();
                ServletFileUpload upload = new ServletFileUpload(factory);
                upload.setHeaderEncoding("UTF-8");
                request.setCharacterEncoding("UTF-8");
               
                List items = upload.parseRequest(request);
                Iterator iter = items.iterator();
               
                long fileMaxSize    = 0;       //file upload 용량 제한
                String filePhysiclNm = "";    //물리파일명
                String uploadPath   = "";      //파일저장경로
               
                while (iter.hasNext()) {
                    FileItem item = (FileItem) iter.next();
                   
                    if (item.isFormField()) {
                        if(item.getFieldName().equals("fileMaxSize")){
                            fileMaxSize = Long.parseLong(item.getString());
                        } else if(item.getFieldName().equals("filePhysiclNm")) {
                            filePhysiclNm = item.getString("UTF-8");
                        } else if(item.getFieldName().equals("uploadPath")) {
                            uploadPath = item.getString("UTF-8");
                        }
                    } else {
                        if (item.getSize() < fileMaxSize) {
                            String filePath = CommonUtil.getRealPath(uploadPath + filePhysiclNm);
                            //System.out.println("filePath:::::::::"+filePath);
                            File uploadedFile = new File(filePath);
                           
                            File upDir = uploadedFile.getParentFile();
                            if(!upDir.isDirectory()){
                                upDir.mkdirs();
                            }
                            if (!uploadedFile.exists()) {
                                uploadedFile.createNewFile();
                            }
                            item.write(uploadedFile);
                        } else {
                        }
                    }
                }
            } else {
            }     
        } catch (Exception ex) {
        }

   
- download -

        String filePhysiclNm = request.getParameter("filePhysiclNm");
        String downloadPath = request.getParameter("uploadPath");        
        try {
            String filePath = CommonUtil.getRealPath(downloadPath + filePhysiclNm);
            System.out.println("filePath:::::::::"+filePath);
            File downloadFile = new File(filePath);
           
            int length = 0;
            ServletOutputStream op = response.getOutputStream();
            ServletContext context = getServlet().getServletConfig().getServletContext();
            String mimetype = context.getMimeType(filePhysiclNm);
           
            response.setContentType((mimetype != null)?mimetype:"application/octet-stream");
            response.setContentLength((int)downloadFile.length());
            response.setHeader("Content-Disposition", "attachment;filename=\"" + filePhysiclNm + "\"" );
           
            byte[] bbuf = new byte[2048];
            DataInputStream in = new DataInputStream(new FileInputStream(downloadFile));
            while ((in != null) && ((length = in.read(bbuf)) != -1)) {
                op.write(bbuf, 0, length);
            }
            in.close();
            op.flush();
            op.close();
        } catch (Exception ex) {
            ex.printStackTrace();
        }

<?xml version="1.0"?>
<!-- validators\PNValidatorErrMessageStyle.mxml -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">

    <!-- Use blue for the error message. -->
    <mx:Style>
        .errorTip { borderColor: #0000FF}
    </mx:Style>

    <!-- Define the PhoneNumberValidator. -->
    <mx:PhoneNumberValidator id="pnV"
        source="{phoneInput}" property="text"
        wrongLengthError="Please enter a 10-digit number."/>

    <!-- Define the TextInput control for entering the phone number. -->
    <mx:TextInput id="phoneInput"/>
    <mx:TextInput id="zipCodeInput"/>
</mx:Application>

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical" creationComplete="test11()">
    <mx:Script>
        <![CDATA[
            import mx.containers.VBox;
            private var tt:Text;
            private var vv:VBox;
            private function test11():void {
                var i:int;
                for(i = 0;i<vb.getChildren().length;i++) {
                   if(vb.getChildAt(i) is VBox) {
                       vv = vb.getChildAt(i) as VBox;
                       var j:int;
                       for(j = 0;j<vv.getChildren().length;j++) {
                           if(vv.getChildAt(j) is Text) {
                                tt = vv.getChildAt(j) as Text;
                                tt.text = "########### i::" + i + ", j::" + j; 
                                trace(tt.id);                    
                           }
                       }
                   }
                }
            }
        ]]>
    </mx:Script>
    <mx:VBox id="vb">
        <mx:VBox >
            <mx:Text id="test1" />
        </mx:VBox>
        <mx:VBox >
            <mx:Label id="ee" />
            <mx:Text id="test2" />
            <mx:Text id="test3" />
        </mx:VBox>
        <mx:VBox >
            <mx:Text id="test4" />
        </mx:VBox>
        <mx:VBox >
            <mx:Text id="test5" />
        </mx:VBox>   
    </mx:VBox>
</mx:Application>