/**
* Download attachment
* @param response
* @param fileName
*/
@GetMapping(value = "/downloadAttachment")
public ResponseEntity<?> downloadAttachment(final HttpServletResponse response, @RequestParam("fileName") String fileName) {
InputStream inputStream = null;
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
try {
// Get file information
ObjectStat objectStat = template.getObjectInfo(bucketName, fileName);
// Set response header
response.setHeader("content-type", objectStat.contentType());
response.setContentType(objectStat.contentType());
// Get file input stream
inputStream = template.getObject(bucketName, fileName);
outputStream = this.readInpurStream(inputStream);
ByteArrayResource resource = new ByteArrayResource(outputStream.toByteArray());
return ResponseEntity.ok()
.contentType(MediaType.APPLICATION_OCTET_STREAM)
.header(HttpHeaders.CONTENT_DISPOSITION, String.format("attachment; filename=%s", URLEncoder.encode(fileName+".pdf", "UTF-8")))
.body(resource);
} catch (Exception e) {
log.error("Export attachment failed:",e);
return ResponseEntity.status(HttpStatus.BAD_REQUEST).body("Exception occurred when downloading the file");
}
}
/**
* Convert input stream to ByteArrayOutputStream
* @param input
* @return
* @throws Exception
*/
public ByteArrayOutputStream readInpurStream(InputStream input) throws Exception{
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len;
try {
while ((len = input.read(buffer)) > -1) {
baos.write(buffer, 0, len);
}
baos.flush();
} catch (IOException e) {
throw new Exception("Illegal flow.");
} finally {
try {
input.close();
} catch (IOException e) {
log.error("file stream shutdown failed.");
}
}
return baos;
}
