java 下载文件

public class TemplateUtil {

public  void downloadTemplate(HttpServletResponse response) throws Exception{

        InputStream inputStream  =null ;
        OutputStream outputStream = null;
        inputStream = this.getClass().getResourceAsStream("/files/template.xlsx");
if (inputStream == null){
throw new Exception("未找到模板文件");
        }

        response.setContentType("application/vnd.ms-excel;charset=utf-8");
        response.setCharacterEncoding("UTF-8");
        response.setHeader("content-disposition","attachment;filename=" + "模板.xlsx");

try{
            outputStream = response.getOutputStream();
byte[] readBytes = new byte[1024];
int read = 0;
while ((read = inputStream.read(readBytes)) != -1){
                outputStream.write(readBytes,0,read);
                outputStream.flush();
            }
        }
catch (Exception e){
// do something
         }
finally {
if (inputStream != null){
                inputStream.close();
            }
if (outputStream != null){
                outputStream.close();
            }
        }
    }
}