<textarea data-dojo-attach-point="txtViewForm" style="font-ize: 15px; width: 100%;height: 100%"  readonly="readonly" >
    this.txtViewForm.value = content;

   /**
     * 綜合利用，線上預覽 txt格式附件
     * @param osName
     * @param docId
     * @throws EcmException
     * @throws IOException
     */
    public static String downloadPrimaryAttach(String osName, String docId) throws EcmException, IOException {
        EntityManager em = null;
        try {
            em = DaoManager.getEntityManager();
            ObjectStore os = ObjectStoreHelper.getObjectStore(osName);
            Document doc = P8DocumentDao.fetchDocumentById(os, docId);
            Collection<ContentTransfer> collection = EngineCollectionUtils.c(doc.get_ContentElements(), ContentTransfer.class);
            Iterator<ContentTransfer> it = collection.iterator();
            ContentTransfer content = it.next();
            InputStream in = content.accessContentStream();
            StringBuffer sb = new StringBuffer();

            //根據特徵碼，來判斷文字檔案編碼格式，目前版本不支援全部格式轉換
            //在網路上查詢資料，沒有找到可用的覆蓋面比較廣的特徵碼集合。求各位大神分享。
            byte[] head = new byte[3]; 
            in.read(head);  
            String code = "GBK";
            if (head[0] == -1 && head[1] == -2 )  {
                  //txt編碼為utf8
                code = "UTF-8"; 
            }else if (head[0] == -2 && head[1] == -1 ){  
                //txt編碼為Unicode
                  code = "UTF-16"; 
            }else if(head[0]==-17 && head[1]==-69 && head[2] ==-65){
                   //txt編碼為UTF-8
                  code = "UTF-8";
            }else if(head[0]==49 && head[1]==46 && head[2] ==-44){
                  //[49, 46, -44]
                  code ="GB2312";
            }
            Charset charset = Charset.forName(code);

            //此處需要設定charset，以便很好的控制頁面上文字的亂碼問題。
            InputStreamReader reader = new InputStreamReader(in,charset);
            BufferedReader bfreader = new BufferedReader(reader);

            String content1 = "";
            while(content1 != null){
                  content1 = bfreader.readLine();
                  if(content1 == null){
                      break;
                  }
                    
               sb.append(content1.trim());
               sb.append("\r\n");
            }
            return sb.toString();
        } catch (Exception e) {
            logger.error("downloadAttach error", e);
            throw new EcmException(ErrorCode.ATTACHMENT_DOWNLOAD_ERROR, "downloadAttach error ", e);
        } finally {
            if (em != null) {
                em.close();
            }
        }
    }