springboot文件下载案例

service层下载文件的方法：

1、加入依赖

<!--文件流处理工具包-->
<dependency>
　　<groupId>commons-io</groupId>
　　<artifactId>commons-io</artifactId>
　　<version>2.2</version>
</dependency>

2、在springboot的application.properties文件中配置文件路径

# 文件存储路径
file.path=C:/image/

3、编写下载代码

　　@Value("${file.path}")  //注入
　　private String filePath;

　　@Override
    public void download(String fileId, HttpServletResponse response) {
        SysFile sysFile=sysFileMapper.selectByPrimaryKey(fileId);
        ServletOutputStream fileOutputStream = null;
        response.setContentType("multipart/form-data");
        try {
            //万能乱码问题解决
            String fileName = new String(sysFile.getFileName().getBytes("UTF-8"), "ISO-8859-1");
            // 设置文件下载响应头
            response.setHeader("Content-disposition", String.format("attachment;filename=%s",fileName));
       } catch (Exception ex) {
            log.error("e:{}",ex);
            throw new BusinessException(BaseResponseCode.OPERATION_ERROR);
       }
        try {
            File file=FileUtils.getFile(filePath,sysFile.getFileName());
            fileOutputStream = response.getOutputStream();
        　　 IOUtils.write(FileUtils.readFileToByteArray(file),fileOutputStream);
       } catch (IOException e) {
            log.error("e:{}",e);
            throw new BusinessException(BaseResponseCode.OPERATION_ERROR);
       }finally {
            try {
                if(fileOutputStream != null){
                    fileOutputStream.close();
               }
           } catch (IOException e) {
                log.error("e:{}",e);
                throw new BusinessException(BaseResponseCode.OPERATION_ERROR);
           }
       }
   }