概述
上传多个文件需要设置input属性multiple。如果上传单个文件则无需设置
上传实现
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
<script src="./jquery.min.js"></script>
</head>
<body>
<form id="uploadForm" action="" method="post" enctype="multipart/form-data">
<h2>多文件上传 </h2>
<table>
<tr>
<td>上传文件： <input type="file" name="file[]" id="file" multiple="multiple" /></td>
</tr>
<tr>
<td>
<input type="button" value="上传" id="but" />
</td>
</tr>
</table>
</form>
</body>
</html>
<script>
//文件上传
$("#but").click(function () {
var formData = new FormData($("#uploadForm")[0]);
$.ajax({
url: '',
type: 'POST',
data: formData,
async: false,
cache: false,
contentType: false,
processData: false,
success: function (returndata) {
alert(returndata);
},
error: function (returndata) {
alert(returndata);
}
});
})
</script>
下载实现
下载文件可以通过a标签实现文件的下载
- 前端代码
let url =""
let link = document.createElement('a')
link.style.display = 'none'
link.href = url
document.body.appendChild(link)
link.click()
// 释放URL对象所占资源
window.URL.revokeObjectURL(url)
// 用完即删
document.body.removeChild(link)
- 后端代码
如果上传的是多个文件，参数是一个文件数组
/**
* 获取上传的图片.
*
* @return 数据
*/
@GetMapping(value = "")
@ResponseBody
public Result downloadFile(HttpServletResponse response, final HttpServletRequest req) {
String title;
try {
title = URLDecoder.decode(req.getParameter("title"), "UTF-8");
} catch (UnsupportedEncodingException e) {
title="压缩包";
}
try {
response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(title+".zip", "UTF-8"));
} catch (UnsupportedEncodingException e) {
response.setHeader("Content-Disposition", "attachment;filename=" + "processs.zip");
e.printStackTrace();
}
response.setHeader("Connection", "close");
response.setHeader("Content-Type", "application/octet-stream");
String piids = req.getParameter("piids");
if (StringUtils.isBlank(piids)){
return new Result(false,"导出失败：流程piid为空");
}
String[] piidArr = StringUtils.split(piids,",");
try {
return new Result(true,integratedQueryService.exportProcessFormInfo(piidArr,response.getOutputStream())) ;
} catch (IOException e) {
return new Result(false,"流程压缩包导出失败，请联系管理员进行解决") ;
}
}
//查询文件，把文件输出到zip输出流
public String exportProcessFormInfo(final String[] piidArr, ServletOutputStream outputStream) {
try (ZipOutputStream zos = new ZipOutputStream(outputStream)) {
if (piidArr.length<=0){
return "流程piid为空，不能导出流程压缩包！";
}
String processImagePath = processImage.getPath();
File file1 = new File(processImagePath);
FileInputStream inputStream;
try {
inputStream = new FileInputStream(file1);
}catch (FileNotFoundException exception){
LOGGER.error("流程截图获取失败，piid:{}",piid);
continue;
// return "流程截图获取失败,piid:"+piid;
}
//流程截图的名称
zos.putNextEntry(new ZipEntry(processImage.getTitle()+".jpg"));
int len;
// 读入需要下载的文件的内容，打包到zip文件
byte[] buffer = new byte[1024];
while ((len = inputStream.read(buffer)) > 0) {
zos.write(buffer, 0, len);
}
zos.closeEntry();
inputStream.close();
attachmentMapper.updateProcessByPiid(piid);
return "流程压缩包导出成功";
}