Spring MVC實現文件下載

時間 2019-11-29

標籤 spring mvc 實現文件下載欄目 Spring 简体版

原文原文鏈接

下載文件①java

下載文件須要將byte數組還原成文件。spring

首先使用mybatis將數據庫中的byte數組查出來，指定文件名(包括格式)。而後使用OutputStream將文件輸入數據庫

@RequestMapping(value = "downPhotoById")
public void downPhotoByStudentId(String id, final HttpServletResponse response){
PhotoEntity entity = this.photoMapper.getPhotoEntityByPhotoId(id);
byte[] data = entity.getPhotoData();
String fileName = entity.getFileName()== null ? "照片.png" : entity.getFileName();
fileName = URLEncoder.encode(fileName, "UTF-8");
response.reset();
response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
response.addHeader("Content-Length", "" + data.length);
response.setContentType("application/octet-stream;charset=UTF-8");
OutputStream outputStream = new BufferedOutputStream(response.getOutputStream());
outputStream.write(data);
outputStream.flush();
outputStream.close();
}

<a href="<%=request.getContextPath() %>/downPhotoById.do?id=8000001">下載照片</a>

下載文件②數組

/** * @Description 下載文件 mybatis

* @author jxldjsnmvc

* @date 2015年12月11日下午6:11:33 app

* @param fileName this

* @param file spa

* @return code

* @throws IOException

public ResponseEntity<byte[]> download(String fileName, File file) throws IOException {

String dfileName = new String(fileName.getBytes("gb2312"), "iso8859-1");

HttpHeaders headers = new HttpHeaders(); headers.setContentType(MediaType.APPLICATION_OCTET_STREAM); headers.setContentDispositionFormData("attachment", dfileName);

return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file), headers, HttpStatus.CREATED); }

下載文件③

//文件下載 主要方法
 public static void download(HttpServletRequest request,    HttpServletResponse response, String storeName, String contentType   ) throws Exception {     request.setCharacterEncoding("UTF-8");   BufferedInputStream bis = null;   BufferedOutputStream bos = null;   //獲取項目根目錄   String ctxPath = request.getSession().getServletContext()     .getRealPath("");     //獲取下載文件露肩   String downLoadPath = ctxPath+"/uploadFile/"+ storeName;   //獲取文件的長度   long fileLength = new File(downLoadPath).length();   //設置文件輸出類型   response.setContentType("application/octet-stream");   response.setHeader("Content-disposition", "attachment; filename="     + new String(storeName.getBytes("utf-8"), "ISO8859-1"));   //設置輸出長度   response.setHeader("Content-Length", String.valueOf(fileLength));   //獲取輸入流   bis = new BufferedInputStream(new FileInputStream(downLoadPath));   //輸出流   bos = new BufferedOutputStream(response.getOutputStream());   byte[] buff = new byte[2048];   int bytesRead;   while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {    bos.write(buff, 0, bytesRead);   }   //關閉流   bis.close();   bos.close();  }  }


下載直接訪問控制器如：http:\\localhost:8080/springmvc/download.do

下載文件④

@RequestMapping("/export")
public ResponseEntity<byte[]> export() throws IOException {
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
headers.setContentDispositionFormData("attachment", "dict.txt");
return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(new File("C:/Users/Administrator/Desktop/a.txt")),
headers, HttpStatus.CREATED);
}