activiti 根据模型ID导出、预览 xml文件

/**根据模型ID导出xml文件
   * @param response
   * @param modelId //模型ID
   * @from  fhadmin.cn
   */
  protected void exportXmlFromModelId(HttpServletResponse response, String modelId) throws Exception{
    Model modelData = repositoryService.getModel(modelId);  
    BpmnJsonConverter jsonConverter = new BpmnJsonConverter();  
    ObjectNode modelNode = (ObjectNode) new ObjectMapper().readTree(repositoryService.getModelEditorSource(modelData.getId()));
    BpmnModel bpmnModel = jsonConverter.convertToBpmnModel(modelNode);  
    BpmnXMLConverter xmlConverter = new BpmnXMLConverter();  
    byte[] bpmnBytes = xmlConverter.convertToXML(bpmnModel);  
    ByteArrayInputStream in = new ByteArrayInputStream(bpmnBytes);  
    //IOUtils.copy(in, response.getOutputStream());  
    String filename = bpmnModel.getMainProcess().getId() + ".bpmn20.xml";  
    /*response.setHeader("Content-Disposition", "attachment; filename=" + filename);  
    response.flushBuffer(); */
    FileUpload.copyFile(in,PathUtil.getProjectpath()+Const.FILEACTIVITI,filename);    //把文件上传到文件目录里面
    FileDownload.fileDownload(response, PathUtil.getProjectpath()+Const.FILEACTIVITI+filename, filename);
    in.close();
  }
  /**根据模型ID预览xml文件
   * @param response
   * @param modelId //模型ID
   * @from  fhadmin.org
   */
  protected String viewXmlFromModelId(String modelId) throws Exception{
    Model modelData = repositoryService.getModel(modelId);  
    BpmnJsonConverter jsonConverter = new BpmnJsonConverter();  
    ObjectNode modelNode = (ObjectNode) new ObjectMapper().readTree(repositoryService.getModelEditorSource(modelData.getId()));
    BpmnModel bpmnModel = jsonConverter.convertToBpmnModel(modelNode);  
    BpmnXMLConverter xmlConverter = new BpmnXMLConverter();  
    byte[] bpmnBytes = xmlConverter.convertToXML(bpmnModel);  
    ByteArrayInputStream in = new ByteArrayInputStream(bpmnBytes);  
    InputStreamReader isr = new InputStreamReader(in,"utf-8");
    BufferedReader bufferedReader = new BufferedReader(isr);
    StringBuffer xmlContent = new StringBuffer(); 
    String lineTxt = null;
    while ((lineTxt = bufferedReader.readLine()) != null) {
      xmlContent.append(lineTxt);
      xmlContent.append("\n");
    }
    isr.close();
    return xmlContent.toString();
  }