question: private Document createDocument ( final InputStream inputStream , final FormDataContentDisposition formDataContentDisposition ) { final Document document = new Document ( ) ; final List < File > files = new ArrayList < File > ( 0 ) ; final List < String > contentTypes = new ArrayList < String > ( 0 ) ; final List < String > fileNames = new ArrayList < String > ( 0 ) ; File file = null ; if ( inputStream != null && formDataContentDisposition != null ) { fileNames . add ( formDataContentDisposition . getFileName ( ) ) ; document . setUploadsFileName ( fileNames ) ; file = writeToFile ( inputStream , formDataContentDisposition . getFileName ( ) ) ; files . add ( file ) ; document . setUploads ( files ) ; contentTypes . add ( MessageFormat . format ( THIRD_PARTY_CONTENT_TYPE , FilenameUtils . getExtension ( file . getPath ( ) ) ) ) ; document . setUploadsContentType ( contentTypes ) ; } return document ; }
target:  This method is used to create Document object to upload the files.