Activiti导出模型文件xml(xml文件超过10K)

Activiti导出超过10K的xml文件时，response 要在获取输出流之前设置header格式

原代码为：

ByteArrayInputStream in = new ByteArrayInputStream(exportBytes);

IOUtils.copy(in, response.getOutputStream());

response.setHeader("Content-Disposition", "attachment; filename="+ filename);

response.flushBuffer();

修改后，代码为：

ByteArrayInputStream in = new ByteArrayInputStream(exportBytes);

response.setHeader("Content-Disposition", "attachment; filename="+ filename);

IOUtils.copy(in, response.getOutputStream());

response.flushBuffer();