Package com.jbstrap.ui.servlet

Class FileManagerServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

com.jbstrap.ui.servlet.FileManagerServlet

All Implemented Interfaces:

Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

@WebServlet("/fileManager/*")
public class FileManagerServlet
extends javax.servlet.http.HttpServlet

File manager servlet.

Files to be downloaded are stored in a temporary cache. An item in the cache is a file, designated with a unique ID. A file is stored in the cache for the time period specified by the parameter JBStrapParamType.DOWNLOAD_LINK_EXPIRATION_TIME. If the file is downloaded or the time expires, the file is removed from the cache and will not be available for download.

If you want to download a file, it is saved to the cache. A JavaScript method call originating from the interface causes the servlet to start file download. The method call is a GET method and you pass the file ID as a parameter to the method. The servlet gets the reference file from the cache and all its metadata and downloads it to the client. The file download request is given an OCTET stream response.

If the file download is impossible (due to the file not being in the cache or an error occurred during file download), the servlet sends a PLAIN/TEXT response with the error text.

Since:

4.0

Author:

JBStrap

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
FileManagerServlet()

Method Summary

Modifier and Type	Method	Description
protected void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
protected void	doPost(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse resp)	File uploadin from file item component
static void	downloadFile(UI ui, JBFile file)	Downloads the file specified by a JBFile object to the UI.
static void	downloadFile(UI ui, String filename, byte[] fileBody)	Downloads the file to the specified UI.

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPut, doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, init, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

FileManagerServlet

public FileManagerServlet()

Method Details

doGet

protected void doGet(javax.servlet.http.HttpServletRequest request,
 javax.servlet.http.HttpServletResponse response)

Overrides:

doGet in class javax.servlet.http.HttpServlet

Parameters:

request - Client request containing file ID in the “id” parameter

response - Response to the request, either an OCTET stream or PLAIN/TEXT

doPost

protected void doPost(javax.servlet.http.HttpServletRequest req,
 javax.servlet.http.HttpServletResponse resp)
               throws javax.servlet.ServletException,
IOException

File uploadin from file item component

Overrides:

doPost in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

IOException

downloadFile

public static void downloadFile(UI ui,
 String filename,
 byte[] fileBody)

Downloads the file to the specified UI.

Parameters:

ui - UI instance

filename - File name

fileBody - File content as a byte array

Throws:

NullPointerException - Thrown if the specified file name or UI is null

downloadFile

public static void downloadFile(UI ui,
 JBFile file)

Downloads the file specified by a JBFile object to the UI.

Parameters:

ui - UI instance

file - The JBFile object representing the file

Throws:

NullPointerException - Thrown if:

• The specified JBFile object is null
• The specified JBFile object does not contain a file name
• The specified JBFile object does not contain a file
• The specified UI is null