Cleaner way of saving a multipart file to a temporarily location.

Author: sagrawal31

grails-app/controllers/com/wizpanda/file/UploadController.groovy

@@ -17,7 +17,8 @@ class UploadController {
     FileUploadService fileUploadService
 
     /**
-     * This endpoint accepts the file in binary form, uploaded by the AJAX based application.
+     * This endpoint accepts the file in the binary form, uploaded by the AJAX based application. This endpoint saves
+     * the file in the temporary directory of the local server which will be cleaned automatically by the system itself.
      *
      * @example
      *
@@ -44,15 +45,15 @@ class UploadController {
      * This is done because if you install this plugin and forget to protect this endpoint then someone may bloat
      * your server by uploading junk files.
      */
-    def index() {
+    def temporarily() {
         if (!Holders.getFlatConfig()["wizpanda.plugins.kernel.allow.file.upload"]) {
             log.warn "App is not allowing to upload files"
             return
         }
 
         log.debug "Temporary upload with $params"
 
-        File file = fileUploadService.saveUploadedFile(params.file)
+        File file = fileUploadService.saveTemporarily(params.file)
         Map result = [filepath: file.getPath(), filename: file.getName()]
 
         // Work around for IE

grails-app/services/com/wizpanda/file/FileUploadService.groovy

@@ -10,63 +10,38 @@ class FileUploadService {
     MessageSource messageSource
 
     /**
-     * Save the uploaded multipart file to a temporary location.
+     * Save the uploaded multipart file in the temporary directory of the local server which will be cleaned
+     * automatically by the system itself.
      *
      * @param multipartFile
-     * @return Saved file with a metaclass method "getOriginalFilename" to get the actual uploaded file name
+     * @return Saved file in a temporary location
      * @throws FileNotFoundException
      * @throws IOException
      */
-    File saveUploadedFile(CommonsMultipartFile multipartFile) throws FileNotFoundException, IOException {
+    File saveTemporarily(CommonsMultipartFile multipartFile) throws FileNotFoundException, IOException {
         if (!multipartFile || multipartFile.isEmpty()) {
             log.debug "Received file is either empty or does not exists"
+
             throw new FileNotFoundException(messageSource.getMessage("kernel.uploaded.file.empty", null, null))
         }
 
-
-        InputStream inputStream
-        FileOutputStream fileOutputStream
-
-        byte[] fileRead = new byte[1024]
-
         try {
             String originalFilename = multipartFile.getOriginalFilename()
-
-            log.debug "Uploaded file's name [$originalFilename]"
-
-            // Remove special characters other than "a-z" "A-Z" "0-9" "." "-" or "_"
-            String fileName = originalFilename.replaceAll("[^a-zA-Z0-9//._-]+", "").toLowerCase()
-
             File temporaryDirectory = Files.createTempDirectory(null).toFile()
-            File temporaryFile = new File(temporaryDirectory, fileName)
-
-            log.debug "File [$fileName] will be saved in [${temporaryDirectory.absolutePath}]"
-
-            inputStream = multipartFile.getInputStream()
-            fileOutputStream = new FileOutputStream(temporaryFile)
 
-            int i = inputStream.read(fileRead)
+            log.debug "Uploaded file [$originalFilename] will be saved in [${temporaryDirectory.absolutePath}]"
 
-            while (i != -1) {
-                fileOutputStream.write(fileRead, 0, i)
-                i = inputStream.read(fileRead)
-            }
-
-            // A dynamic method to get the original name of the file which was received
-            temporaryFile.metaClass.getOriginalFilename = { ->
-                return originalFilename
-            }
+            File temporaryFile = new File(temporaryDirectory, originalFilename)
+            multipartFile.transferTo(temporaryFile)
 
             return temporaryFile
-        } catch (FileNotFoundException e) {
+        } catch (IllegalStateException e) {
             log.error "Problem saving file", e
-            throw e
+            throw new FileNotFoundException(e.message)
+
         } catch (IOException e) {
             log.error "Exception saving file", e
             throw e
-        } finally {
-            fileOutputStream?.close()
-            inputStream?.close()
         }
     }
 }