这篇文章主要介绍了java实现文件上传、下载、图片预览,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下

多文件保存到本地：

@ResponseBody

@RequestMapping(value = "/uploadApp",produces = { "application/json;charset=UTF-8" },method= RequestMethod.POST)

public String uploadApp( HttpServletRequest request,@RequestParam("file") MultipartFile[] file) throws IOException {

try {

if(file.length > 0) {

String name = file[0].getOriginalFilename().split(";")[0];

String fileUrlName = CommonEnum.FILEPATH+"/"+name;

for (int i = 0; i < file.length; i++) {

FileUtils.copyInputStreamToFile(file[i].getInputStream(), new File(fileUrlName, file[i].getOriginalFilename().split(";")[1]));

}

return "success";

}else{

return "null";

}

}catch (Exception e){

e.printStackTrace();

return "error";

}

}

下载文件：

@RequestMapping(value = "/download", method = RequestMethod.GET)

@ResponseBody

public void download(@RequestParam Map data, HttpServletRequest request,HttpServletResponse response) throws FileNotFoundException {

String time = DateUtil.formatFromDate("yyyyMMddHHmmss", new Date());

List> urllist = companyService.findByIMG(data);

String path = (String) urllist.get(0).get("imgurl");

String docx = StringUtils.substringAfterLast(path, ".");

String fileName = time+"."+docx; // 文件的默认保存名

InputStream inStream = new FileInputStream(path);// 文件的存放路径

response.reset();

response.setContentType("bin");

response.addHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");

byte[] b = new byte[100];

int len;

try {

while ((len = inStream.read(b)) > 0)

response.getOutputStream().write(b, 0, len);

inStream.close();

} catch (IOException e) {

e.printStackTrace();

}

}

/**

* 读取图片

*/

@RequestMapping(value = "/iomoreimgcom", produces = {

"application/json;charset=UTF-8" }, method = RequestMethod.GET)

@ResponseBody

public synchronized void iomoreimgcom(HttpServletRequest request, HttpServletResponse response) throws Exception {

String url = request.getParameter("url");

File file = new File(url);

BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file));

BufferedOutputStream bos = new BufferedOutputStream(response.getOutputStream());

response.setHeader("Content-Type", "image/jpeg");

byte b[] = new byte[1024];

int read;

try {

while ((read = bis.read(b)) != -1) {

bos.write(b, 0, read);

}

//request.getRequestDispatcher("/components/hazard/yscchird.html").forward(request, response);

} catch (Exception e) {

// TODO: handle exception

} finally {

if (bos != null) {

bos.close();

}

if (bis != null) {

bis.close();

}

}

}

前端请求直接拼接图片路径即可。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。