一、文件上传
页面type为file的input标签，提交到后台的文件可以用request获取，获取后的是mutipleFile类型，可以直接getbyte获取其字节，再调用接口上传至七牛
public JsonResponse<String> uploadFile(MultipartFile file) {
JsonResponse<String> response = new JsonResponse<String>();
try {
if(file.getBytes().length==0||StringUtils.isBlank(file.getOriginalFilename())){
response.setStatus(ResponseInfo.ERROR.getStatus());
response.setMsg("文件上传错误！请重新上传！");
return response;
}
String fileUploadMsg = fileUpload(file.getBytes(), file.getOriginalFilename());
if(FileUtil.isFileId(fileUploadMsg)){
response.setData(fileUploadMsg);
return response;
}else{
response.setStatus(ResponseInfo.ERROR.getStatus());
response.setMsg(fileUploadMsg);
return response;
}
} catch (IOException e) {
e.printStackTrace();
response.setStatus(ResponseInfo.ERROR.getStatus());
response.setMsg("文件上传失败！请重新上传！");
return response;
}
}```
```@Override
public String fileUpload(byte[] data, String originalFileName) {
if(StringUtils.isBlank(originalFileName)){
return "文件名称为空";
}
if(data.length > 10485760){//单个文件不可以超过10M
return "文件过大";
}
String ext = originalFileName.substring(originalFileName.lastIndexOf(".")+1);
String regex = "^JPG|JEPG|PNG|DOC|DOCX|PDF$";
Pattern pattern = Pattern.compile(regex, Pattern.CASE_INSENSITIVE);//忽略大小写
if(!pattern.matcher(ext).matches()){
return "文件格式不正确";
}
//eg_file表创建一条记录
File file = new File();
file.setFileId(IdWorker.nextId(ModelPrefix.FILE));
String fileName = originalFileName.substring(0,originalFileName.lastIndexOf("."));
file.setFileName(fileName);
file.setExt(ext);
file.setByteCount(data.length);
fileMapper.insertSelective(file);
try{
FileUtil.fileUploadByByteArray(data, file.getFileId());
return file.getFileId();
}catch(Exception e){
fileMapper.deleteByPrimaryKey(file.getFileId());
e.printStackTrace();
}
return null;
}```
##二、文件下载
####先页面请求获取七牛里文件的地址url
```@Override
public JsonResponse<String> getDownloadUrlByFileId(String fileId) {
JsonResponse<String> response = new JsonResponse<String>();
if(StringUtils.isBlank(fileId)){
response.setStatus(ResponseInfo.ERROR.getStatus());
response.setMsg("文件编号不能为空！");
return response;
}
File file = new File();
file.setFileId(fileId);
file = fileMapper.selectByPrimaryKey(file);
if(file!=null&&StringUtils.isNotBlank(file.getFileName())&&StringUtils.isNotBlank(file.getExt())){
String fileName=file.getFileName()+"."+file.getExt();
try {
String fileUrl = FileUtil.getFileUrl(fileId, fileName);
response.setData(fileUrl);
return response;
} catch (Exception e) {
e.printStackTrace();
}
}else{
response.setStatus(ResponseInfo.ERROR.getStatus());
response.setMsg("文件不存在！");
return response;
}
return response;
}```
####再次请求上面获得的地址，即可下载文件。此处做异步下载，以标签a的形式在前端实现
scope.downloadFile=function(){
if(scope.egFileId){
var url=__ctx+"/file/getDownloadUrlByFileId/"+scope.egFileId;
//获取文件名
$http.get(url).success(function(data){
if(data.status==0){
if (navigator.userAgent.indexOf('Firefox') >= 0){
//解决火狐浏览器不兼容问题
var b=window.open();
setTimeout(function(){
b.location=data.data;
}, 200);
}else{
var elementObj= document.createElement("a");
elementObj.href = data.data;
elementObj.click();
}
}
})
}
}```
三、也可做同步下载（不推荐，响应时间较长）
页面发送请求给服务器，服务器先获取url，再向url请求到文件并返回页面
public static ResponseEntity<byte[]> downLoadWithGet(String url,String fileName,String ext) throws Exception{
CloseableHttpClient httpclient = HttpClients.createDefault();
try {
HttpGet httpget = new HttpGet(url);
httpget.setHeader("Accept-Encoding", "identity");
HttpResponse response = httpclient.execute(httpget);
int status = response.getStatusLine().getStatusCode();
if (status >= 200 && status < 300) {
HttpEntity entity = response.getEntity();
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
byte[] buffer = new byte[1024*10];
InputStream is = entity.getContent();
int len = 0;
while((len=is.read(buffer))!=-1){
outStream.write(buffer,0,len);
}
outStream.close();
is.close();
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
headers.setContentLength(entity.getContentLength());
headers.setContentDispositionFormData("attachment", fileName+"."+ext);
return new ResponseEntity<byte[]>(outStream.toByteArray(),headers, HttpStatus.CREATED);
} else {
throw new ClientProtocolException("Unexpected response status: " + status);
}
} finally {
httpclient.close();
}
}```
