读取Blob字段类型数据在页面显示

dzt

使用的是IBATIS持久层框架。。。
 
public String queryBlobVal() {
    template = sqlMapClientTemplateFactory.getTemplate(DataType.SIGN);
    if (StringUtils.isNotEmpty(schemaType)) {
      if (schemaType.equals("CZ")) {
        model.setSchema(dataSourceManager.getCzSchema());
      } else {
        model.setSchema(dataSourceManager.getQzSchema());
      }
    }
    //要查询的表和字段，查询时使用IBATIS持久层框架
    if (StringUtils.isNotEmpty(tableName) && StringUtils.isNotEmpty(columnName)) {
      Map map = (Map) template.queryForObject(SQL_BLOBVAL_ID, model);
      Blob blob = (Blob) map.get("BLOBVAL");
      InputStream in = null;
      try {
        if (blob != null && blob.length() > 0) {
          in = blob.getBinaryStream();
          int byteCount = 0;
          byte[] buffer = new byte[4096];
          int bytesRead = -1;
          while ((bytesRead = in.read(buffer)) != -1) {
            getResponse().getOutputStream().write(buffer, 0, bytesRead);
            if (model.getColumnType().equalsIgnoreCase("WORD")) {
              getResponse().setContentType("application/msword");
              getResponse().setContentType("application/x-download");
              getResponse().addHeader("Content-Disposition",
                  "attachment;filename=\"" + model.getStationId() + "_" + model.getColumnName() + ".doc\"");
            } else {
              getResponse().setContentType("image/jpeg");
            }
            byteCount += bytesRead;
          }
        } else {
          render(getResponse(), "暂无数据", "text/html");
        }
      } catch (Exception e) {
        e.printStackTrace();
      } finally {
        try {
          if (in != null) {
            in.close();
          }
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
    }
    return null;
  }