GetSession and getCookies vs getWriter
Does one have to use the getSession and getCookies from the HttpServletRequest object before retrieving the Writer object from the HttpServletResponse's getWriter function? Or does the order not matter? Some books and online information provide conflicting information on the order of these. Thank You.
getCookies is for retrieving the cookies that are stored and getSession is for Http Session object. Both of them are not required to get a Writer object, which is used to write something to the screen.
Go thru a good JSP book and they will explain these more.
For a simple JSP, you dont need either getcookies or getsession....
Similar Messages
-
Difference between getSession() and getSession(true)
I am new to servlets. I couldn't find any difference between request.getSession()
and request.getSession(true) methods. Could any one help me plese.
Thanks.I am new to servlets. I couldn't find any difference
between request.getSession()
and request.getSession(true) methods. Could
any one help me plese.
Thanks.getSession() is a convenience method shortcut for getSession(true). There is no difference. There is a difference between getSession() and getSession(false) though...
(ie, if getSession(false) will not make a new session if one does not already exist...) -
Difference between getSession() and getSession(boolean)
What is the difference between sessionObj.getSession() and sessionObj.getSession(true)?
The reason would be if you wanted to check if the user had a session but didn't want to create a new session if they didn't.
i.e.
HttpSession session = request.getSession(false);
if (session == null) { // we know the user hasn't got a session and we haven't created one for them
response.sendRedirect("login.jsp"); // make them login
return;
} -
Ias1.0.2,Jserv, getSession and setAttribute
While getSession and setAttribute are usable from JSP pages, when including the same calls in servlets, I get the following Error:
(ERROR) ajp12: Servlet Error: java.lang.NoSuchMethodError: javax.servlet.http.HttpServletRequest: method getSession()Ljavax/servlet/http/HttpSession; not found: <ul>
Is this a configuration issue or is this just a limitation of using Jserv and it's conformance to servlet spec 2.0.
I have triple checked jserv.properties, wrapper.classpath and it does include servlet.jar.Hi,
I actually dont know how to solve your problem,but I am sure you cansolve mine.I have created BC4J application which works fine when I run from JDeveloper.When I deploy it on 9iAS its giving me problem,it says connection (connection name) not defined.
Exact message is ->
Error Message: oracle.jbo.JboException: JBO-33003: Connection name exeter not defined
My connection.properties file does have this connection entry,can you tell me how to solve this problem.
For installation on 9ias I did the following :
1) Made a jar file of BC4J application using the deployment profile.
2)Created Business com JSP application and used the created jar file of BC4J application
3)Deployed using local mode.
Hope its clear,and you'll solve my problem.
Rgds,
Mandar
null -
File upload, download using ADF UIX and not JSP
I have examples for the file upload, download using JSP
But I want to use ADF UIX. Look and feel in this is impressing and I want to use this. Any one have example for this.
Users will select a file from their desktop
This will be stored into the database (Any document. Word, Excel)
When they query the records then the UIX column need to give a hyperlink. Clicking on the link should prompt to download the file to the local systemSure, I use the Apache Commons File Upload package, so that is what I will discuss here ( [Commons File Upload|http://commons.apache.org/fileupload/] ).
The Commons File Upload uses instances of ProgressListener to receive upload progress status. So first create a simple class that implements ProgressListener:
public class ProgressListenerImpl implements ProgressListener {
private int percent = 0;
public int getPercentComplete() {
return percent;
public void update(long pBytesRead, long pContentLength, int pItems) {
if (pContentLength > -1) { //content length is known;
percent = (new Long((pBytesRead / pContentLength) * 100)).intValue();
}So in your Servlet that handles file upload you will need to create an instance of this ProgressListenerImpl, register it as a listener and store it in the session:
ServletFileUpload upload = new ServletFileUpload();
ProgressListenerImpl listener = new ProgressListenerImpl();
upload.setProgressListener(listener);
request.getSession().setAttribute("ProgressListener", listener);
...Now create another servlet that will retrieve the ProgressListenerImpl, get the percent complete and write it back (how you actually write it back is up to you, could be text, an XML file, a JSON object, up to you):
ProgressListenerImpl listener = (ProgressListenerImpl) request.getSession().getAttribute("ProgressListener");
response.getWriter().println("" + listener.getPercentComplete());
...Then your XMLHttpRequest object will call this second servlet and read the string returned as the percent complete.
HTH -
How set and get parameter for a session of a portlet (Java)
I would like get parameter and set parameter for a portlet in portal 9.02. This parameter must be availbale during the session of the portal.
With Java Servlet
// I retrieve my session
HttpServletRequest httpreq = (HttpServletRequest)req;
HttpServletResponse httpresp = (HttpServletResponse)resp;
HttpSession session = httpreq.getSession();
//And after i can get or set some parameter for this servlet
//Example
session.setAttribute("MyEmployeeNumber","600000");
String id = (String)session.getAttribute("MyEmployeeNumber");
// But with Portlet in portal, i can't do it.
PortletRenderRequest pr= (PortletRenderRequest)httpreq.getAttribute(HttpCommonConstants.PORTLET_RENDER_REQUEST);
String sUser=pr.getUser().getName();
ProviderSession session=pr.getSession();
// But after if i want get or set a value in this session i have a internal error 500
session.setAttribute("MyEmployeeNumber","600000");
I would like my parameter is avalaible during a session for a user in each page of the portal, because my portlet is on each page.I have almost the same problem. I tried as you suggested, but it doesn't work yet.
provider.xml
<session>true</session>
<passAllUrlParams>true</passAllUrlParams>
My code in my jsp-portlet is
<%@page contentType="text/html; charset=windows-1252"
import="oracle.portal.provider.v2.render.PortletRenderRequest"
import="oracle.portal.provider.v2.render.PortletRendererUtil"
import="oracle.portal.provider.v2.http.HttpCommonConstants"
import="oracle.portal.provider.v2.ParameterDefinition"
import="oracle.portal.provider.v2.render.http.HttpPortletRendererUtil"
%>
<%@page session="true"%>
<%
PortletRenderRequest pReq = (PortletRenderRequest)request.getAttribute(HttpCommonConstants.PORTLET_RENDER_REQUEST);
String valueSession = (String)pReq.getAttribute("sesion");
if (valueSession != null) {
pReq.setAttribute("session", "value1");
out.println("<br>(1)valueSession != null");
out.println("<br>(1)valueSession : " + pReq.getAttribute("session"));
} else {
pReq.setAttribute("session", "value2");
out.println("<br>(2)valueSession == null");
out.println("<br>(2)valueSession : " + pReq.getAttribute("session"));
%>
And i always get as result:
(2)valueSession == null
(2)valueSession : value2
Even when i send values (post) at the same page or browsing between tabs:
I check my provider registration and it has the value "once per session"
I have portal 9.0.2.2.14
Thanks -
Problem with Hibernate Connection and MySQL
I have the following setup:
J2EE web-application, Java Servlets, Jsp, Hibernate for DB persistence, MySQL 4 (InnoDB tables)
I have not specified any connection pool parameters (c3p0) in my hibernate.cfg.xml, as the default settings should suffice for my purposes.
I use the SessionFactory object as follows.
In my database access class, I have a static declaration that initialises the new SessionFactory.
Then, I use Session session = sessionFactory.getSession(); and session.close(); to do my DB access.
Likewise, when storing data into the DB, I use a Transaction object, and use transaction.commit(); at the end of database access.
The problem is:
When I store data into the database, the changes do not occur on the website. In other words, the data gets stored into the tables (I check that via phpMyAdmin) but when accessing it, it only gets the old data. This is a serious problem as I am developing a website with attached CMS that will be used to update the pages.
The OTHER problem is:
Instead of having a static initialisation of the SessionFactory object, I created a new one every time I needed to access the database. Although I had a sessionFactory.close(); statement at the end of the database acccess, I got an exception:
"java.sql.SQLException: User db_user already has more than 'max_user_connections' active connections"
At the very moment I don't have access to my code.
If somebody has a suggestion or a solution to the problem, please reply.
Also, I will supply any code that is necessary to identify the problem.
AndersThanks for the tip, but how do you mean to update the object?
Here is the code that stores the data into the database:
'sessionFactory' is a static SessionFactory object.
public static int saveOrUpdate ( Object object ) {
int flag = 0; // 0 is true
LOG.info("CMSLogic >>> saveOrUpdate() - object: " + object );
Session session = null;
Transaction transaction = null;
try {
session = sessionFactory.openSession();
transaction = session.beginTransaction();
LOG.info("CMSLogic >>> saveOrUpdate() - object to save or update: " + object );
session.saveOrUpdate(object);
// Flush the session
if ( session!= null )
session.flush();
transaction.commit();
} catch ( Exception e ) {
e.printStackTrace ();
transaction.rollback();
flag = 1;
} finally {
try{
if (session != null) {
session.close();
} catch (Exception e) {
LOG.error("CMSLogic >>> saveOrUpdate() - threw exception: " + e);
return flag;
}Further, here is the code that fetches the data from the DB:
public static Item getItemByURL ( String url ) {
// Verify the URL
if ( url.charAt(0) == '/' ) url = url.substring (1);
String [] urlArr = url.split( "/" );
LOG.info("BusinessLogic >>> getItemByURL() - split url: urlArr.length: " + urlArr.length );
for ( int i = 0; i < urlArr.length; i++ )
System.out.println ( urlArr[i] + ", " );
if ( urlArr == null ) return null;
if ( urlArr.length == 0 ) return null;
if ( urlArr.length > 4 ) return null; // If the path depth is more than 3 levels, abort
// Fetch data from DB
List<Item> items = null;
Session session = null;
Query query = null;
try {
session = sessionFactory.openSession();
if ( urlArr.length == 1 ) {
query = session.createQuery(
"FROM Item WHERE section.sectionKey LIKE 'root' " +
"AND filename LIKE '" + urlArr[0] + "'" );
else if ( urlArr.length == 2 ) {
query = session.createQuery(
"FROM Item WHERE section.sectionKey LIKE '" + urlArr[0] + "' " +
"AND filename LIKE '" + urlArr[1] + "'" );
else if ( urlArr.length == 3 ) {
query = session.createQuery(
"FROM Item WHERE section.sectionKey LIKE '" + urlArr[1] + "' " +
"AND section.parentSection.sectionKey LIKE '" + urlArr[0] + "' " +
"AND filename LIKE '" + urlArr[2] + "'" );
else { // if ( urlArr.length == 4 ) {
query = session.createQuery(
"FROM Item WHERE section.sectionKey LIKE '" + urlArr[2] + "' " +
"AND section.parentSection.sectionKey LIKE '" + urlArr[1] + "' " +
"AND section.parentSection.parentSection.sectionKey LIKE '" + urlArr[0] + "' " +
"AND filename LIKE '" + urlArr[3] + "'" );
items = query.list();
LOG.info("BusinessLogic >>> getItemByURL() - items = query.list(): " + items );
// Load the related revisions, too
if ( !items.isEmpty() ) {
Hibernate.initialize ( items.get(0).getRevisions() );
LOG.info("BusinessLogic >>> getItemByURL() - initialised revisions for item." );
Hibernate.initialize ( items.get(0).getRevisions().get(0).getTemplate() );
LOG.info("BusinessLogic >>> getItemByURL() - initialised template for first revision." );
// Flush the session
if ( session!= null )
session.flush();
} catch ( Exception e ) {
e.printStackTrace ();
LOG.error("BusinessLogic >>> getItemByURL() - threw exception: " + e );
} finally {
session.close();
//sessionFactory.close(); // !!!???
// Return query results
if ( items == null ) return null;
else if ( items.isEmpty() == true ) return null;
else {
LOG.info("BusinessLogic >>> getItemByURL() - items.get(0).getRevisions().size(): " + items.get(0).getRevisions().size() );
LOG.info("BusinessLogic >>> getItemByURL() - items.get(0).getRevisions().get(0): " + items.get(0).getRevisions().get(0) );
return items.get(0);
}Any constructive suggestions and helpful comments are more than welcome.
I have been struggling with this problem for a while now.
Anders -
Very poor implementation of XMLHttpRequest streaming with Safari for Window
I hope this post reaches Apple engineers. This is critical for us to resolve this. I am a member of the developer network, so if using incident support is necessary, it can be used. Do not hesitate to contact me with any questions. I have implemented a test to compare XMLHttpRequest streaming performance for different browsers. Safari for Windows 5.0.3 had the worst results compared to Chrome and Firefox. Furthermore, I think this problem was introduced after Safari 3. The test consists of a server pushing messages of about 350 bytes to the browser at a rate of about 300/s. Once server pushes 10,000 messages, it closes the connection and browser opens new one repeating the cycle. There were several problems associated with Safari: 1) Safari could not process much more then 300 messages/s, that is quite low. Chrome had no problem processing 1,000. If, for example, 500 m/s was used, Safari would quickly allocate hundreds of meg of memory and crash. 2) Safari starts with about 64MEG of memory allocated. Once the test page is opened, memory quickly climes to 150MEG and as test progresses to >400MEG. Once the connection closes, it drops to 150MEG again. Chrome's memory did not fluctuate at all staying at 32MEG for the same test. 3) CPU was steadily claiming as test progressed and then dropped as connection was reset, creating CPU spikes. It reached about 50% CPU before connection was closed. Chrome's CPU stayed at about 2% all the time. This is the code: Server. Should be run with the latest Java Tomcat 7. Configure Tomcat to use Http11NioProtocol: package test; import java.io.IOException; import java.io.PrintWriter; import java.text.SimpleDateFormat; import java.util.Date; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.catalina.comet.CometEvent; import org.apache.catalina.comet.CometProcessor; @SuppressWarnings("serial") public class WebFrameworkServletXHRReconnects extends HttpServlet implements CometProcessor { @Override public void event(CometEvent event) throws IOException, ServletException { HttpServletRequest request = event.getHttpServletRequest(); HttpServletResponse response = event.getHttpServletResponse(); if (event.getEventType() == CometEvent.EventType.BEGIN) { System.out.println("Begin for session: " + request.getSession(true).getId() + " " + response.getWriter()); response.setHeader("pragma", "no-cache,no-store"); response.setHeader("cache-control", "no-cache,no-store,max-age=0,max-stale=0"); event.setTimeout(Integer.MAX_VALUE); PrintWriter out = response.getWriter(); SimpleDateFormat formatter = new SimpleDateFormat("mm:ss: "); for (int i = 0; i < 10000; i++) { out.print("{\"messageType\":8448,\"requestId\":"0",\"eventType\":1,\"symbolId\" :[\"BAC.EA\",0],\"fields\":[{\"header\":"0",\"type\":6,\"data\":[3993,2]},{\"hea der\":"55",\"type\":6,\"data\":[1185,2]},{\"header\":54,\"type\":6,\"data\":[321 8,2]},{\"header\":"5",\"type\":6,\"data\":[6617,2]},{\"header\":52,\"type\":4,\" data\":[15]},{\"header\":"12",\"type\":6,\"data\":[1700,2]}]}"); out.flush(); if (i % 10 == 0) { try { //Thread.sleep(60); Thread.sleep(30); } catch (InterruptedException e) { } } if (i % 100 == 0) { System.out.println(formatter.format(new Date()) + i); } } out.close(); event.close(); } else if (event.getEventType() == CometEvent.EventType.ERROR) { event.close(); } else if (event.getEventType() == CometEvent.EventType.END) { event.close(); } } } client: <script type="text/javascript" src="log4js.js">
</script>
<script type="text/javascript">
var api;
var log = new Log(Log.DEBUG, Log.popupLogger);
var byteoffset;
var perocessedMessages;
function connect() {
perocessedMessages = 0;
byteoffset = 0;
id = 0;
api = new XMLHttpRequest;
api.onreadystatechange = onreadystatechange;
api.onerror = onerror;
log.debug('connect');
api.open("GET", "http://localhost/Test/Controller", true);
api.send("");
function onreadystatechange() {
switch (api.readyState) {
case 3:
change();
break;
case 4:
disconnect();
break;
function change() {
connected = true;
var buffer = api.responseText;
var newdata = buffer.substring(byteoffset);
byteoffset = buffer.length;
while (1) {
var x = newdata.indexOf("<activ>");
if (x != -1) {
y = newdata.indexOf("</activ>", x);
if (y != -1) {
processMessage(newdata.substring((x + 7), y));
newdata = newdata.substring(y + 8);
else {
break;
else {
break;
byteoffset = buffer.length - newdata.length;
function processMessage(msg) {
var objJson = eval('(' + msg + ')');
perocessedMessages++;
//if (perocessedMessages % 100 == 0) {
// log.debug('' + perocessedMessages);
function disconnect() {
log.debug('disconnect');
connect();
function onerror() {
log.debug('onerror');
</script>I hope this post reaches Apple engineers. This is critical for us to resolve this. I am a member of the developer network, so if using incident support is necessary, it can be used.
We're a user-to-user forum, ilyag. So it'd be better for you to use the Apple Bug Reporter if you want to ensure someone from Apple sees your post:
http://developer.apple.com/bugreporter/ -
Session does not end even when i close browser
when i close firefox/IE the session continues ,What i need is that i am adding amount in shopping cart ,but the amount adds to old amount even when i open a new browser window ,
i hv checked that my browser will remove cookies when i will close mozilla
i hv also printed total=0 in servlet's ini method but the init method is called only once and total does not reset to 0,does 'th the call to init method is made everytime we start a new session via browser ,it does not get called whn i close the current browser and open new one.how to destroy the older servlet?
I m using s=request.getSession()
and s.setAttribute("billamnt",total)
the code of the servlet is
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
public class addtocart extends HttpServlet
HttpSession s;
PrintWriter pw;
int total,cam,mob;
public void init()
total=0;
cam=0;
mob=0;
System.out.println("inside cart init");
public void service(HttpServletRequest req,HttpServletResponse res) throws IOException
s=req.getSession();
res.setContentType("text/html");
pw=res.getWriter();
pw.println("<html><body><a href="+"mobs"+">Mobile</a><br><a href="+"cams"+">Camera</a><form method = "+"post "+"action ="+"bill"+"><br><input type= "+"submit"+"></form></body></html>");
if(req.getParameter("csony")!=null)
cam=cam+Integer.parseInt(req.getParameter("csony"));
if(req.getParameter("clg")!=null)
cam=cam+Integer.parseInt(req.getParameter("clg"));
if(req.getParameter("cnokia")!=null)
mob=mob+Integer.parseInt(req.getParameter("cnokia"));
if(req.getParameter("cerricson")!=null)
mob=mob+Integer.parseInt(req.getParameter("cerricson"));
s.setAttribute("cambill",new Integer(cam));
s.setAttribute("mobbill",new Integer(mob));
s.setAttribute("billamnt",new Integer(cam+mob));
public void doPost(HttpServletRequest req,HttpServletResponse res)
public void doGet(HttpServletRequest req,HttpServletResponse res)
}Wats the problem?
Message was edited by:
pooja_k_onlineThe servlet is not created on a session basis. All users share the same servlet object. The servlet is created once when the servlet is first called in the context, then is maintaned until the server shuts down.
You should not store any state in the servlet. You should use the HttpSession object you get from the request object to store the totals, and all other values. You should not use the servlet to hold on to a session object, as multiple users would see the SAME session that way. If you need to use the session in multiple methods, then you should pass that object as parameter, not by making it a class member.
You also shouldn't put the work in the service method of the HttpServlet. You should put it in either the doGet or doPost method (and if you want to make it happen for both type requests, call doPost from the doGet method and put the work in the doPost method).
For example:
public class ShoppingCartServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) {
doPost(request, response);
public void doPost(HttpServletRequest request, HttpServletResponse response) {
HttpSession session = request.getSession();
Integer cambill = (Integer)session.getAttribute("cambill");
int cam = 0;
if(cambill != null) cam = cambill.intValue();
Integer mobbill = (Integer)session.getAttribute("mobbill");
int mob = 0;
if(mobbill != null) mob = mobbill.intValue();
Integer billamnt = (Integer)session.getAttribute("billamnt");
int total = 0;
if(billamnt != null) total = billamnt.intValue();
String csony = request.getParameter("csony");
if (csony != null) cam += Integer.parseInt(csony);
String clg = request.getParameter("clg");
if (clg != null) cam+= Integer.parseInt(clg);
String cnokia = request.getParameter("cnokia");
if (cnokia != null) mob += Integer.parseInt(cnokia);
String cerricson = request.getAttribute("cerricson");
if (cerricson != null) mob += Integer.parseInt(cerricson);
total = cam + mob;
session.setAttribute("cambill",new Integer(cam));
session.setAttribute("mobbill",new Integer(mob));
session.setAttribute("billamnt",new Integer(total));
PrintWriter pw=response.getWriter();
pw.println("<html><body><a href="+"mobs"+">Mobile</a><br><a href="+"cams"+">Camera</a><form method = "+"post "+"action ="+"bill"+"><br><input type= "+"submit"+"></form></body></html>");
pw.close();
}Message was edited by:
stevejluke -
PROBLEM IN INTERNET EXPLORER WITH THE fileupload API
i written a servlet to upload a file which will upload a file to a specific directory..............
this program is working with opera or Mozilla browser.......but it is not working in internet explorer 8.
i can not understand what is the problem..............
code working with opera or Mozilla and also for other browser but not with explorer 8..
my code is
index.jsp is a welcome file which is used to select a file which i want to upload
index.jsp
<html>
<head><title>Upload page</title></head></p> <p><body>
<form action="uploadFile" method="post" enctype="multipart/form-data" name="form1" id="form1">
<center>
<table border="2">
<tr>
<td align="center"><b>Multipale file Uploade</td>
</tr>
<tr>
<td>
Specify file: <input name="file" type="file" id="file">
<td> </tr>
<tr>
<td>
<div align="center">
<input type="submit" name="Submit" value="Submit files"/>
</div></td>
</table>
<center>
<p>
</p>
</form>
</body>
</html>
uploadFile.java is servlet file which is used to upload the file in the specific location....
the code of uploadFile.java is
uploadFile.java
import java.io.IOException;
import java.util.Iterator;
import java.lang.Object;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.List;
import java.io.*;
import java.io.File;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.fileupload.disk.DiskFileItemFactory ;
import org.apache.commons.fileupload.*;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class uploadFile extends HttpServlet
public void doPost(HttpServletRequest request,HttpServletResponse response)
throws IOException,ServletException {
HttpSession session=request.getSession();
PrintWriter out=response.getWriter();
ServletConfig config=getServletConfig();
boolean isMultipart = ServletFileUpload.isMultipartContent(request);
if(!isMultipart)
else
FileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
List items = null;
try {
items = upload.parseRequest(request);
} catch (FileUploadException e) {
e.printStackTrace();
Iterator itr = items.iterator();
while (itr.hasNext()) {
FileItem item = (FileItem) itr.next();
if (item.isFormField()) {
} else {
try {
String itemName = item.getName();
if(itemName.equals(""))
session.setAttribute("itemName",itemName);
response.sendRedirect("index.jsp");
File savedFile = new File(config.getServletContext().getRealPath("/")+"uploadedFiles/"+itemName);
item.write(savedFile);
out.println("Your file has been saved at the loaction:"+"\n"+config.getServletContext().getRealPath("/")+"uploadedFiles"+"\\"+itemName);
} catch (Exception e) {
e.printStackTrace();
Now i want to solve my problem in my code...............
pleasde help me.............First of all, please do not shout in topic titles. It is rude.
Secondly, please buy a new keyboard. Your dot key hangs all the time, it reads annoying.
Back to your problem: did you read the FAQ available at the [FileUpload homepage|http://commons.apache.org/fileupload]? There´s something stated about a misbehaviour in IE and how to fix it using Commons IO. It is namely sending the complete client´s file path instead of only the file name. -
Namburi,
When you said you used the Reg Exp tool, did you use it only as
preconfigured by the iMT migrate application wizard?
Because the default configuration of the regular expression tool will only
target the files in your ND project directories. If you wish to target
classes outside of the normal directory scope, you have to either modify the
"Source Directory" property OR create another instance of the regular
expression tool. See the "Tool" menu in the iMT to create additional tool
instances which can each be configured to target different sets of files
using different sets of rules.
Usually, I utilize 3 different sets of rules files on a given migration:
spider2jato.xml
these are the generic conversion rules (but includes the optimized rules for
ViewBean and Model based code, i.e. these rules do not utilize the
RequestManager since it is not needed for code running inside the ViewBean
or Model classes)
I run these rules against all files.
See the file download section of this forum for periodic updates to these
rules.
nonProjectFileRules.xml
these include rules that add the necessary
RequestManager.getRequestContext(). etc prefixes to many of the common
calls.
I run these rules against user module and any other classes that do not are
not ModuleServlet, ContainerView, or Model classes.
appXRules.xml
these rules include application specific changes that I discover while
working on the project. A common thing here is changing import statements
(since the migration tool moves ND project code into different jato
packaging structure, you sometime need to adjust imports in non-project
classes that previously imported ND project specific packages)
So you see, you are not limited to one set of rules at all. Just be careful
to keep track of your backups (the regexp tool provides several options in
its Expert Properties related to back up strategies).
----- Original Message -----
From: <vnamboori@y...>
Sent: Wednesday, August 08, 2001 6:08 AM
Subject: [iPlanet-JATO] Re: Use Of models in utility classes - Pease don't
forget about the regular expression potential
Thanks Matt, Mike, Todd
This is a great input for our migration. Though we used the existing
Regular Expression Mapping tool, we did not change this to meet our
own needs as mentioned by Mike.
We would certainly incorporate this to ease our migration.
Namburi
--- In iPlanet-JATO@y..., "Todd Fast" <toddwork@c...> wrote:
All--
Great response. By the way, the Regular Expression Tool uses thePerl5 RE
syntax as implemented by Apache OROMatcher. If you're doing lotsof these
sorts of migration changes manually, you should definitely buy theO'Reilly
book "Mastering Regular Expressions" and generate some rules toautomate the
conversion. Although they are definitely confusing at first,regular
expressions are fairly easy to understand with some documentation,and are
superbly effective at tackling this kind of migration task.
Todd
----- Original Message -----
From: "Mike Frisino" <Michael.Frisino@S...>
Sent: Tuesday, August 07, 2001 5:20 PM
Subject: Re: [iPlanet-JATO] Use Of models in utility classes -Pease don't
forget about the regular expression potential
Also, (and Matt's document may mention this)
Please bear in mind that this statement is not totally correct:
Since the migration tool does not do much of conversion for
these
utilities we have to do manually.Remember, the iMT is a SUITE of tools. There is the extractiontool, and
the translation tool, and the regular expression tool, and severalother
smaller tools (like the jar and compilation tools). It is correctto state
that the extraction and translation tools only significantlyconvert the
primary ND project objects (the pages, the data objects, and theproject
classes). The extraction and translation tools do minimumtranslation of the
User Module objects (i.e. they repackage the user module classes inthe new
jato module packages). It is correct that for all other utilityclasses
which are not formally part of the ND project, the extraction and
translation tools do not perform any migration.
However, the regular expression tool can "migrate" any arbitrary
file
(utility classes etc) to the degree that the regular expressionrules
correlate to the code present in the arbitrary file. So first andforemost,
if you have alot of spider code in your non-project classes youshould
consider using the regular expression tool and if warranted adding
additional rules to reduce the amount of manual adjustments thatneed to be
made. I can stress this enough. We can even help you write theregular
expression rules if you simply identify the code pattern you wish to
convert. Just because there is not already a regular expressionrule to
match your need does not mean it can't be written. We have notnearly
exhausted the possibilities.
For example if you say, we need to convert
CSpider.getDataObject("X");
To
RequestManager.getRequestContext().getModelManager().getModel(XModel.class);
Maybe we or somebody else in the list can help write that regularexpression if it has not already been written. For instance in thelast
updated spider2jato.xml file there is already aCSpider.getCommonPage("X")
rule:
<!--getPage to getViewBean-->
<mapping-rule>
<mapping-rule-primarymatch>
<![CDATA[CSpider[.\s]*getPage[\s]*\(\"([^"]*)\"]]>
</mapping-rule-primarymatch>
<mapping-rule-replacement>
<mapping-rule-match>
<![CDATA[CSpider[.\s]*getPage[\s]*\(\"([^"]*)\"]]>
</mapping-rule-match>
<mapping-rule-substitute>
<![CDATA[getViewBean($1ViewBean.class]]>
</mapping-rule-substitute>
</mapping-rule-replacement>
</mapping-rule>
Following this example a getDataObject to getModel would look
like this:
<mapping-rule>
<mapping-rule-primarymatch>
<![CDATA[CSpider[.\s]*getDataObject[\s]*\(\"([^"]*)\"]]>
</mapping-rule-primarymatch>
<mapping-rule-replacement>
<mapping-rule-match>
<![CDATA[CSpider[.\s]*getDataObject[\s]*\(\"([^"]*)\"]]>
</mapping-rule-match>
<mapping-rule-substitute>
<![CDATA[getModel($1Model.class]]>
</mapping-rule-substitute>
</mapping-rule-replacement>
</mapping-rule>
In fact, one migration developer already wrote that rule andsubmitted it
for inclusion in the basic set. I will post another upgrade to thebasic
regular expression rule set, look for a "file uploaded" posting.Also,
please consider contributing any additional generic rules that youhave
written for inclusion in the basic set.
Please not, that in some cases (Utility classes in particular)
the rule
application may be more effective as TWO sequention rules ratherthan one
monolithic rule. Again using the example above, it will convert
CSpider.getDataObject("Foo");
To
getModel(FooModel.class);
Now that is the most effective conversion for that code if that
code is in
a page or data object class file. But if that code is in a Utilityclass you
really want:
>
RequestManager.getRequestContext().getModelManager().getModel(FooModel.class
So to go from
getModel(FooModel.class);
To
RequestManager.getRequestContext().getModelManager().getModel(FooModel.class
You would apply a second rule AND you would ONLY run this rule
against
your utility classes so that you would not otherwise affect yourViewBean
and Model classes which are completely fine with the simplegetModel call.
<mapping-rule>
<mapping-rule-primarymatch>
<![CDATA[getModel\(]]>
</mapping-rule-primarymatch>
<mapping-rule-replacement>
<mapping-rule-match>
<![CDATA[getModel\(]]>
</mapping-rule-match>
<mapping-rule-substitute>
<![CDATA[RequestManager.getRequestContext().getModelManager().getModel(]]>
</mapping-rule-substitute>
</mapping-rule-replacement>
</mapping-rule>
A similer rule can be applied to getSession and other CSpider APIcalls.
For instance here is the rule for converting getSession calls toleverage
the RequestManager.
<mapping-rule>
<mapping-rule-primarymatch>
<![CDATA[getSession\(\)\.]]>
</mapping-rule-primarymatch>
<mapping-rule-replacement>
<mapping-rule-match>
<![CDATA[getSession\(\)\.]]>
</mapping-rule-match>
<mapping-rule-substitute>
<![CDATA[RequestManager.getSession().]]>
</mapping-rule-substitute>
</mapping-rule-replacement>
</mapping-rule>
----- Original Message -----
From: "Matthew Stevens" <matthew.stevens@e...>
Sent: Tuesday, August 07, 2001 12:56 PM
Subject: RE: [iPlanet-JATO] Use Of models in utility classes
Namburi,
I will post a document to the group site this evening which has
the
details
on various tactics of migrating these type of utilities.
Essentially,
you
either need to convert these utilities to Models themselves or
keep the
utilities as is and simply use the
RequestManager.getRequestContext.getModelManager().getModel()
to statically access Models.
For CSpSelect.executeImmediate() I have an example of customhelper
method
as a replacement whicch uses JDBC results instead of
CSpDBResult.
matt
-----Original Message-----
From: vnamboori@y... [mailto:<a href="/group/SunONE-JATO/post?protectID=081071113213093190112061186248100208071048">vnamboori@y...</a>]
Sent: Tuesday, August 07, 2001 3:24 PM
Subject: [iPlanet-JATO] Use Of models in utility classes
Hi All,
In the present ND project we have lots of utility classes.
These
classes in diffrent directory. Not part of nd pages.
In these classes we access the dataobjects and do themanipulations.
So we access dataobjects directly like
CSpider.getDataObject("do....");
and then execute it.
Since the migration tool does not do much of conversion forthese
utilities we have to do manually.
My question is Can we access the the models in the postmigration
sameway or do we need requestContext?
We have lots of utility classes which are DataObjectintensive. Can
someone suggest a better way to migrate this kind of code.
Thanks
Namburi
[email protected]
[email protected]
[Non-text portions of this message have been removed]
[email protected]
[email protected]Namburi,
When you said you used the Reg Exp tool, did you use it only as
preconfigured by the iMT migrate application wizard?
Because the default configuration of the regular expression tool will only
target the files in your ND project directories. If you wish to target
classes outside of the normal directory scope, you have to either modify the
"Source Directory" property OR create another instance of the regular
expression tool. See the "Tool" menu in the iMT to create additional tool
instances which can each be configured to target different sets of files
using different sets of rules.
Usually, I utilize 3 different sets of rules files on a given migration:
spider2jato.xml
these are the generic conversion rules (but includes the optimized rules for
ViewBean and Model based code, i.e. these rules do not utilize the
RequestManager since it is not needed for code running inside the ViewBean
or Model classes)
I run these rules against all files.
See the file download section of this forum for periodic updates to these
rules.
nonProjectFileRules.xml
these include rules that add the necessary
RequestManager.getRequestContext(). etc prefixes to many of the common
calls.
I run these rules against user module and any other classes that do not are
not ModuleServlet, ContainerView, or Model classes.
appXRules.xml
these rules include application specific changes that I discover while
working on the project. A common thing here is changing import statements
(since the migration tool moves ND project code into different jato
packaging structure, you sometime need to adjust imports in non-project
classes that previously imported ND project specific packages)
So you see, you are not limited to one set of rules at all. Just be careful
to keep track of your backups (the regexp tool provides several options in
its Expert Properties related to back up strategies).
----- Original Message -----
From: <vnamboori@y...>
Sent: Wednesday, August 08, 2001 6:08 AM
Subject: [iPlanet-JATO] Re: Use Of models in utility classes - Pease don't
forget about the regular expression potential
Thanks Matt, Mike, Todd
This is a great input for our migration. Though we used the existing
Regular Expression Mapping tool, we did not change this to meet our
own needs as mentioned by Mike.
We would certainly incorporate this to ease our migration.
Namburi
--- In iPlanet-JATO@y..., "Todd Fast" <toddwork@c...> wrote:
All--
Great response. By the way, the Regular Expression Tool uses thePerl5 RE
syntax as implemented by Apache OROMatcher. If you're doing lotsof these
sorts of migration changes manually, you should definitely buy theO'Reilly
book "Mastering Regular Expressions" and generate some rules toautomate the
conversion. Although they are definitely confusing at first,regular
expressions are fairly easy to understand with some documentation,and are
superbly effective at tackling this kind of migration task.
Todd
----- Original Message -----
From: "Mike Frisino" <Michael.Frisino@S...>
Sent: Tuesday, August 07, 2001 5:20 PM
Subject: Re: [iPlanet-JATO] Use Of models in utility classes -Pease don't
forget about the regular expression potential
Also, (and Matt's document may mention this)
Please bear in mind that this statement is not totally correct:
Since the migration tool does not do much of conversion for
these
utilities we have to do manually.Remember, the iMT is a SUITE of tools. There is the extractiontool, and
the translation tool, and the regular expression tool, and severalother
smaller tools (like the jar and compilation tools). It is correctto state
that the extraction and translation tools only significantlyconvert the
primary ND project objects (the pages, the data objects, and theproject
classes). The extraction and translation tools do minimumtranslation of the
User Module objects (i.e. they repackage the user module classes inthe new
jato module packages). It is correct that for all other utilityclasses
which are not formally part of the ND project, the extraction and
translation tools do not perform any migration.
However, the regular expression tool can "migrate" any arbitrary
file
(utility classes etc) to the degree that the regular expressionrules
correlate to the code present in the arbitrary file. So first andforemost,
if you have alot of spider code in your non-project classes youshould
consider using the regular expression tool and if warranted adding
additional rules to reduce the amount of manual adjustments thatneed to be
made. I can stress this enough. We can even help you write theregular
expression rules if you simply identify the code pattern you wish to
convert. Just because there is not already a regular expressionrule to
match your need does not mean it can't be written. We have notnearly
exhausted the possibilities.
For example if you say, we need to convert
CSpider.getDataObject("X");
To
RequestManager.getRequestContext().getModelManager().getModel(XModel.class);
Maybe we or somebody else in the list can help write that regularexpression if it has not already been written. For instance in thelast
updated spider2jato.xml file there is already aCSpider.getCommonPage("X")
rule:
<!--getPage to getViewBean-->
<mapping-rule>
<mapping-rule-primarymatch>
<![CDATA[CSpider[.\s]*getPage[\s]*\(\"([^"]*)\"]]>
</mapping-rule-primarymatch>
<mapping-rule-replacement>
<mapping-rule-match>
<![CDATA[CSpider[.\s]*getPage[\s]*\(\"([^"]*)\"]]>
</mapping-rule-match>
<mapping-rule-substitute>
<![CDATA[getViewBean($1ViewBean.class]]>
</mapping-rule-substitute>
</mapping-rule-replacement>
</mapping-rule>
Following this example a getDataObject to getModel would look
like this:
<mapping-rule>
<mapping-rule-primarymatch>
<![CDATA[CSpider[.\s]*getDataObject[\s]*\(\"([^"]*)\"]]>
</mapping-rule-primarymatch>
<mapping-rule-replacement>
<mapping-rule-match>
<![CDATA[CSpider[.\s]*getDataObject[\s]*\(\"([^"]*)\"]]>
</mapping-rule-match>
<mapping-rule-substitute>
<![CDATA[getModel($1Model.class]]>
</mapping-rule-substitute>
</mapping-rule-replacement>
</mapping-rule>
In fact, one migration developer already wrote that rule andsubmitted it
for inclusion in the basic set. I will post another upgrade to thebasic
regular expression rule set, look for a "file uploaded" posting.Also,
please consider contributing any additional generic rules that youhave
written for inclusion in the basic set.
Please not, that in some cases (Utility classes in particular)
the rule
application may be more effective as TWO sequention rules ratherthan one
monolithic rule. Again using the example above, it will convert
CSpider.getDataObject("Foo");
To
getModel(FooModel.class);
Now that is the most effective conversion for that code if that
code is in
a page or data object class file. But if that code is in a Utilityclass you
really want:
>
RequestManager.getRequestContext().getModelManager().getModel(FooModel.class
So to go from
getModel(FooModel.class);
To
RequestManager.getRequestContext().getModelManager().getModel(FooModel.class
You would apply a second rule AND you would ONLY run this rule
against
your utility classes so that you would not otherwise affect yourViewBean
and Model classes which are completely fine with the simplegetModel call.
<mapping-rule>
<mapping-rule-primarymatch>
<![CDATA[getModel\(]]>
</mapping-rule-primarymatch>
<mapping-rule-replacement>
<mapping-rule-match>
<![CDATA[getModel\(]]>
</mapping-rule-match>
<mapping-rule-substitute>
<![CDATA[RequestManager.getRequestContext().getModelManager().getModel(]]>
</mapping-rule-substitute>
</mapping-rule-replacement>
</mapping-rule>
A similer rule can be applied to getSession and other CSpider APIcalls.
For instance here is the rule for converting getSession calls toleverage
the RequestManager.
<mapping-rule>
<mapping-rule-primarymatch>
<![CDATA[getSession\(\)\.]]>
</mapping-rule-primarymatch>
<mapping-rule-replacement>
<mapping-rule-match>
<![CDATA[getSession\(\)\.]]>
</mapping-rule-match>
<mapping-rule-substitute>
<![CDATA[RequestManager.getSession().]]>
</mapping-rule-substitute>
</mapping-rule-replacement>
</mapping-rule>
----- Original Message -----
From: "Matthew Stevens" <matthew.stevens@e...>
Sent: Tuesday, August 07, 2001 12:56 PM
Subject: RE: [iPlanet-JATO] Use Of models in utility classes
Namburi,
I will post a document to the group site this evening which has
the
details
on various tactics of migrating these type of utilities.
Essentially,
you
either need to convert these utilities to Models themselves or
keep the
utilities as is and simply use the
RequestManager.getRequestContext.getModelManager().getModel()
to statically access Models.
For CSpSelect.executeImmediate() I have an example of customhelper
method
as a replacement whicch uses JDBC results instead of
CSpDBResult.
matt
-----Original Message-----
From: vnamboori@y... [mailto:<a href="/group/SunONE-JATO/post?protectID=081071113213093190112061186248100208071048">vnamboori@y...</a>]
Sent: Tuesday, August 07, 2001 3:24 PM
Subject: [iPlanet-JATO] Use Of models in utility classes
Hi All,
In the present ND project we have lots of utility classes.
These
classes in diffrent directory. Not part of nd pages.
In these classes we access the dataobjects and do themanipulations.
So we access dataobjects directly like
CSpider.getDataObject("do....");
and then execute it.
Since the migration tool does not do much of conversion forthese
utilities we have to do manually.
My question is Can we access the the models in the postmigration
sameway or do we need requestContext?
We have lots of utility classes which are DataObjectintensive. Can
someone suggest a better way to migrate this kind of code.
Thanks
Namburi
[email protected]
[email protected]
[Non-text portions of this message have been removed]
[email protected]
[email protected] -
Delete File's after Reading on server
Hi All,
I am uploading & reading a CSV or Txt file which contains data. The servlet reads & successfully inserting date into the backend db tables.
For the uploading purposes i am using com.oreilly.servlet.MultipartWrapper servlet class which does successfully upload's the selected file from JSP page to the server location which i mentioned in web.xml.
Now my requirement is after reading the file from the uploaded location i want to delete the file. can anyone suggest me on this??
I have tried using file.delete(); method but it does not seem working. Any suggestions???
Code :
web.xml
<filter>
<filter-name>MultipartFilter</filter-name>
<filter-class>com.oreilly.servlet.MultipartFilter</filter-class>
<init-param>
<param-name>uploadDir</param-name>
<param-value>C:/Temp/</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>MultipartFilter</filter-name>
<url-pattern>FileUpload</url-pattern>
</filter-mapping>
<servlet>
<servlet-name>FileUpload</servlet-name>
<servlet-class>com.test.FileUpload</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>FileUpload</servlet-name>
<url-pattern>FileUpload</url-pattern>
</servlet-mapping>
JSP Code :
<FORM name="file_upload" action="<%=request.getContextPath()%>/FileUpload" method="post" enctype="multipart/form-data">
<TABLE border="1" width="400" CELLPADDING="4">
<tr>
<td colspan="2" align="center">Enter or Select the file for Upload</td>
</tr>
<tr>
<td align="center">Enter or Select a file: <input type="file" name="fileInfo" value="" /></td>
</tr>
<tr>
<td colspan="2" align="center"><input type="submit" name="button" value="Upload File" />
</td>
</tr>
</TABLE>
</FORM>
Servlet Code :
import import javax.servlet.*;
import com.Ostermiller.util.CSVParser;
import com.oreilly.servlet.MultipartWrapper;
public class FileUpload extends HttpServlet {
boolean recordInserted = false;
Connection dbconn = null;
CallableStatement cstmt1 = null;
DatabaseUtils dbUtils = new DatabaseUtils();
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException,
FileNotFoundException {
HttpSession session = request.getSession();
PrintWriter out = response.getWriter();
try {
dbconn = dbUtils.getConnection(session);
// to get the content type information from JSP Request Header
String contentType = request.getContentType();
Enumeration enum1 = request.getParameterNames();
while (enum1.hasMoreElements()) {
String name = (String) enum1.nextElement();
String values[] = request.getParameterValues(name);
if (values != null) {
for (int i = 0; i < values.length; i++) {
cat.debug(name + " (" + i + "): " + values);
if (request instanceof MultipartWrapper) {
try {
// Cast the request to a MultipartWrapper
MultipartWrapper multi = (MultipartWrapper) request;
// Show which files we received
Enumeration files = multi.getFileNames();
while (files.hasMoreElements()) {
String names = (String) files.nextElement();
String filename = multi.getFilesystemName(names);
String type = multi.getContentType(names);
File f = multi.getFile(names);
cat.debug("name: " + names);
cat.debug("filename: " + filename);
cat.debug("type: " + type);
if (f != null) {
if (type.equals("application/vnd.ms-excel") || type.equals("text/plain")) {
cat.debug(filename);
cat.debug(" | length: " + f.length() + "\r");
cat.debug("File Uploaded Successfully"); String filePath = "C:/Temp/" + filename;
cat.debug("FILE PATH : " + filePath);
// mergeStatenos.setUploadedFilePath(filePath);
values = CSVParser.parse(new FileReader(filePath));
cat.debug("VALUES LENGTH : " + values.length);
String[][] values = CSVParser.parse(new FileReader(f));
for (int i = 0; i < values.length; i++) {
for (int j = 0; j < values[i].length; j++) {
try {
cstmt1 = dbconn.prepareCall("{call spj_add_file_records (?, ?, ?, ?, ?)}");
cstmt1.setString(1, values[i][0]);
cstmt1.setString(2, values[i][1]);
cstmt1.setString(3, values[i][2]);
cstmt1.setString(4, values[i][3]);
cstmt1.setString(5, "1");
recordInserted = cstmt1.execute();
// // create the return message container
ReturnMessages rm = new ReturnMessages(session);
rm.add(new ReturnMessage("File upload records inserted successful"));
} catch (SQLException sqle) {
cat.error(LogException.convertStackTraceToString(sqle));
new LogDBException(sqle.getMessage(), request);
ReturnMessages rm = new ReturnMessages(session);
rm.add(new ReturnMessage("A Database Error Occurred while inserting records. Please Try Again. "));
} finally {
dbUtils.cleanUp(cstmt1);
f.delete();
} else {
f.delete();
cat.debug(filename+ " is not a XLS file or text file, cannot upload.");
} catch (Exception e) {
cat.debug("Could not upload file/files");
cat.debug(e.getMessage());
e.printStackTrace();
// out.println("</PRE>");
Any Suggestions???rajeshchenji wrote:
Files are with minimum 10,000+ records...so can you tell me how i can upload & read into memory.I would read the documentation for that tool you are using to do the file upload. I am not at all interested in rummaging through that unformatted mess of code you dumped there. You're looking for something that can upload to an OutputStream rather than a File, then use that to output to a ByteArrayOutputStream.
Or something that can give you an InputStream that reads directly from the upload. -
How can I use active user session that's in an application scope Hashtable?
First of all, is it possible to use the same session after a user exits and then returns?
Second, if it is possible, then please tell me what I need to do. So far, this is what I have been doing...
1.) The user submits login credentials
2.) The user is authenticated.
3.) The user does not have an existing session, so a new one is created.
4.) The user closes the browser.
5.) The user returns to login page and submits login credentials.
6.) The user is authenticated.
7.) The user has an existing session, so it should be used.
This is where I'm having trouble. All active sessions for my application are stored in a Hashtable. I have been using <%@ page session="false" %> so that a new session is not automatically created. Each time before I create a new session, I check my Hashtable to see if that user has an existing session. If a session exists for that user, then I would like to continue using that session if possible. I have used the methods request.getSession() and request.getSession(false), but a new session is always returned.
I could create a new session, copy the attributes from the old session(which is stored in my Hashtable) to the new session, and then invalidate the old session, but I'd rather not do that.
Is there a way that I can use existing sessions that I have stored in my Hashtable?First of all, is it possible to use the same session after a user exits and then returns?No, I don't think so. Let me explain why. When the server creates a session object for each client, it needs to know which client is making the request. Remember that HTTP is a stateless protocol. Every time a client makes a request, it sends some sort of session id to the server to let the server know who is trying to make the request. The server will then check to see if a session object exists for that particular client and if so, it will make sure that the max inactive interval (maximum time alloted for that client's session) has not been exceeded. If every thing is okay, then the client can access the session object to get values that were previously placed there. There are many ways that servers try to keep track of clients. One way is to have the clients write the session ID using cookies. But, many people like disallow cookies. So some servers do what is known as URL rewriting. That is, they will write the session ID on the end of the query string. This can also be accomplished programmatically, but it can be taxing to do. Anways, the point is that the client and the server have to have some sort of link between each other and that link is the session ID. So, if the browser is closed, the session ID is lost. That particular client will be forced to get a new session ID the next time the following code is executed:
//create a session object and set its values
HttpSession session = request.getSession(true);>
Second, if it is possible, then please tell me what I
need to do. So far, this is what I have been doing...
1.) The user submits login credentials
2.) The user is authenticated.
3.) The user does not have an existing session, so a
new one is created.
4.) The user closes the browser.
5.) The user returns to login page and submits login
credentials.
6.) The user is authenticated.
7.) The user has an existing session, so it should
be used.If you really want to do something like this, you could make up your own ID and store it as a cookie on the client. I've never tried anything like this before so you would have to do your own research. Are you sure you want to do something like this. There is a reason why it works the way it does. There is also a reason why you want to keep the session timeout value some what small. Let me give you an example of some craziness with sessions. A client we once had wanted to keep their sessions open for 4 hours because they said there clients simply did not like to log in all the time. I nearly gasped when I was told we needed to do this. When you make the session time out large (i.e. the maxInactiveInterval( )), then session objects stick around longer in the server. Let's say a client logs into the server and receives a session object. Then, the client makes a few requests. The server knows to keep the session alive as long as the time between requests has not exceeded 4 hours. Then the client closes the browser. How is the server suppose to know that the browser was closed. Well, it doesn't. It just knows to check times between requests. So, that particular session object won't be garbage collected until the session times out. What if a whole bunch of clients did this. Yucko. The server would have a whole bunch of session objects living in memory. What a waste. This is all above and beyond the typical security problems that can arise from having a session open for so long. To make a long story short, you really shouldn't do what you are trying to do unless it is the nature of the app.
>
This is where I'm having trouble. All active sessions
for my application are stored in a Hashtable. I have
been using <%@ page session="false" %> so that a new
session is not automatically created. Each time
before I create a new session, I check my Hashtable
to see if that user has an existing session. If a
session exists for that user, then I would like to
continue using that session if possible. I have used
the methods request.getSession() and
request.getSession(false), but a new session is
always returned.
I could create a new session, copy the attributes from
the old session(which is stored in my Hashtable) to
the new session, and then invalidate the old session,
but I'd rather not do that.
Is there a way that I can use existing sessions that I
have stored in my Hashtable? -
Urgent - can't set managed bean value using a form, getting null
I have a form with a bean -- unbelievably, I can't get the values entered into the form by the user to get stored into the bean. Everything is null... I've looked at a zillion examples, posts and compared etc...yet still can't see what is missing.
Here's part of a trace :
[cc]Dec-31 01:25:02 ApplicationImpl - Created bean resourceBean successfully
[cc]Dec-31 01:25:02 ApplicationImpl - Storing resourceBean in scope request
[cc]Dec-31 01:25:02 VariableResolverImpl - resolveVariable: Resolved variable:id=null name=null
[cc]Dec-31 01:25:02 ValueBindingImpl - getValue Result:id=null name=null
[cc]Dec-31 01:25:02 ValueBindingImpl - -->Returning id=null name=null
If you have any ideas, please let me know--it seems just as I solve one JSF issue, I run into another on unexpectedly simple things.
Here's the ResourceBean.java, the bean-config.xml and my jsp.
package com.intalio.qa.tcm.view.beans;
import java.util.Map;
import javax.faces.context.FacesContext;
import javax.faces.model.SelectItem;
import org.apache.log4j.Logger;
import com.intalio.qa.exceptions.DuplicateIdException;
import com.intalio.qa.tcm.model.Resource;
import com.intalio.qa.tcm.view.builders.ResourceBuilder;
import com.intalio.qa.tcm.view.util.FacesUtils;
* Resource backing bean.
public class ResourceBean extends RootBean {
* Class logger
public static final Logger LOG =
Logger.getLogger(ResourceBean.class);
* The Resource id
private String id = null;
* The Resource name
private String name = null;
* Description
private String description= null;
* the resource type id associated with the Resource
private String resourceTypeId= null;
private static SelectItem[] resourceTypeIds = new SelectItem[] {
new SelectItem("External Software"),
new SelectItem("Hardware"),
new SelectItem("Intalio Product Software"),
new SelectItem("Machine - Dual CPU"),
new SelectItem("Machine - CPU Single"),
new SelectItem("Memory - UNIX"),
new SelectItem("Memory - Windows") };
* @return Returns the resourceTypeIds.
public SelectItem[] getResourceTypeIds() {
return resourceTypeIds;
* @param resourceTypeIds The resourceTypeIds to set.
public void setResourceTypeIds(SelectItem[] typeIds) {
resourceTypeIds = typeIds;
* Default constructor.
public ResourceBean() {
super();
init();
* Initializes ResourceBean.
* @see RootBean#init()
protected void init() {
/*True, but I'd strongly recommend instead using:
FacesContext fContext = FacesContext.getCurrentInstance();
Map requestParams = fContext.getExternalContext().getRequestParameterMap();
String companyId = (String) requestParams.get("companyID");
The getRequest(), getSession(), and getContext() methods of ExternalContext should only be used as a last resort.*/
* Backing bean action to update Resource.
* @return the navigation result
public String updateAction() {
LOG.info("updateAction is invoked");
try {
Resource Resource = ResourceBuilder.createResource(this);
LOG.info("ResourceId = " + Resource.getId());
// viewServicesManager.getResourceService().updateResource(Resource);
} catch (Exception e) {
String msg = "Could not update Resource";
LOG.error(msg, e);
FacesUtils.addErrorMessage(msg + ": Internal Error.");
return ActionResult.FAILURE;
LOG.info("Resource with id of " + id + " was updated successfully.");
return ActionResult.SUCCESS;
* Backing bean action to create a new Resource.
* @return the navigation result
public String addAction() {
try {
Resource resource = ResourceBuilder.createResource(this);
LOG.info("resource created: " + resource.getName() + " with typeId = " + resource.getResourceTypeId());
viewServicesManager.getResourceService().saveResource(resource);
} catch (DuplicateIdException de) {
String msg = "This id already exists";
LOG.info(msg);
FacesUtils.addErrorMessage(msg);
return ActionResult.RETRY;
} catch (Exception e) {
String msg = "Could not save Resource";
LOG.error(msg, e);
FacesUtils.addErrorMessage(msg + ": Internal Error");
return ActionResult.FAILURE;
String msg = "Resource with id of " + id + " was created successfully.";
LOG.info(msg);
return ActionResult.SUCCESS;
* Backing bean action to delete Resource.
* @return the navigation result
public String deleteAction() {
LOG.info("deleteAction is invoked");
try {
// Resource Resource = ResourceBuilder.createResource(this);
// viewServicesManager.getResourceService().deleteResource(Resource);
//remove the ResourceList inside the cache
// FacesUtils.resetManagedBean(BeanNames.RESOURCE_LIST_BEAN);
} catch (Exception e) {
String msg = "Could not delete Resource. ";
LOG.error(msg, e);
FacesUtils.addErrorMessage(null, msg + "Internal Error.");
return ActionResult.FAILURE;
String msg = "Resource with id of " + id + " was deleted successfully.";
LOG.info(msg);
FacesUtils.addInfoMessage(msg);
return ActionResult.SUCCESS;
public String getId() {
return id;
* Invoked by the JSF managed bean facility.
* <p>
* The id is from the request parameter.
* If the id is not null, by using the id as the key,
* the Resource bean is initialized.
* @param newQueryId the query id from request parameter
public void setId(String newId) {
LOG.info("setId " + newId);
id = newId;
public String getName() {
return name;
public void setName(String newName) {
name = newName;
public String getDescription() {
return description;
public void setDescription(String newDescription) {
description = newDescription;
public String getResourceTypeId() {
return resourceTypeId;
public void setResourceTypeId(String newResourceTypeId) {
resourceTypeId = newResourceTypeId;
public String toString() {
return "id=" + id + " name=" + name;
<!-- view -->
<managed-bean>
<description>
Managed bean
</description>
<managed-bean-name>applicationBean</managed-bean-name>
<managed-bean-class>
com.intalio.qa.tcm.view.beans.ApplicationBean
</managed-bean-class>
<managed-bean-scope>application</managed-bean-scope>
<managed-property>
<property-name>viewServicesManager</property-name>
<value>#{viewServicesManagerBean}</value>
</managed-property>
</managed-bean>
<managed-bean>
<description>
View service manager impl for business services
</description>
<managed-bean-name>viewServicesManagerBean</managed-bean-name>
<managed-bean-class>
com.intalio.qa.tcm.view.beans.ViewServicesManagerBean</managed-bean-class>
<managed-bean-scope>application</managed-bean-scope>
</managed-bean>
<managed-bean>
<description>
Backing bean that contains product information.
</description>
<managed-bean-name>resourceBean</managed-bean-name>
<managed-bean-class>
com.intalio.qa.tcm.view.beans.ResourceBean
</managed-bean-class>
<managed-bean-scope>request</managed-bean-scope>
<managed-property>
<property-name>viewServicesManager</property-name>
<value>#{viewServicesManagerBean}</value>
</managed-property>
</managed-bean>
</faces-config>
<f:view>
<h:form id="createResourceForm" target="dataFrame">
<h:outputText value="#{applicationBean.dummyVariable}" rendered="true" />
<div align="center">
<head>
<link href="../../css/stylesheet.css" rel="stylesheet" type="text/css">
<FONT color="#191970" size="4" face="Arial">Resources View</FONT>
</head>
<table style="margin-top: 2%" width="35%" cellpadding="10">
<div align="left">
<FONT color="#191970" size="3" face="Arial">Update Resources </FONT>
</div>
<tr>
<td align="center" valign="top" align="center" style="" bgcolor="white" />
<table>
<tbody>
<tr>
<td align="left" styleClass="header" width="100" />
<td align="left" width="450" />
</tr>
<tr>
<td align="right" width="100"><h:outputText value="Id" /></td>
<td align="left" width="450"><h:inputText value="#{resourceBean.id}" id="id"/> <h:message for="id" styleClass="errorMessage" /></td>
</tr>
<tr>
<td align="right" width="100"><h:outputText value="Name" /></td>
<td align="left" width="450"><h:inputText value="#{resourceBean.name}" id="name" /> <h:message for="name" styleClass="errorMessage" /></td>
</tr>
<tr>
<!--td align="right" width="100" valign="bottom"><h:outputText value="Type" /></td>
<td align="left" width="550"><h:selectOneMenu>
<f:selectItems value="#{resourceBean.resourceTypeIds}" />
</h:selectOneMenu> <h:outputText value="#{resourceBean.resourceTypeId}" id="dresourceTypeId" /> <h:message for="resourceTypeId" styleClass="errorMessage" />
</td>
</tr>
<tr>
<td align="right" width="100" valign="bottom"><h:outputText value="Description" /></td>
<td align="left" width="450"><h:inputText value="#{resourceBean.description}" id="description" size="96" /> <h:message for="description" styleClass="errorMessage" /></td>
</tr>
</tbody>
</table>
</h:form>
</td>
<!-- END DATA FORM -->
<!-- BEGIN COMMANDS -->
<td width="30%" align="left" valign="top"><h:form id="buttonCommandsForm">
<h:panelGroup id="buttons">
<h:panelGrid columns="1" cellspacing="1" cellpadding="2" border="0" bgcolor="white">
<h:commandButton value="Add" style="height:21px; width:51px;font-size:8pt; font-color: black;" action="#{resourceBean.addAction}">
</h:commandButton>
<h:commandButton id="deleteCB" value="Delete" style="height:21px; width:51px;font-size:8pt" action="#{resourceBean.deleteAction}">
</h:commandButton>
<h:commandButton id="spaceFillerButton" style="height:21px; width:51px;font-size:8pt;background-color: #ffffff;color: #ffffff;border: 0px;">
</h:commandButton>
<h:commandButton id="saveCB" value="Save" style="height:21px; width:51px;font-size:8pt" action="#{resourceBean.saveAction}">
</h:commandButton>
<h:commandButton id="updateCB" value="Update" style="height:21px; width:51px;font-size:8pt" action="#{resourceBean.updateAction}">
</h:commandButton>
</h:panelGrid>
</h:panelGroup>
</h:form> <!-- end buttons --></td>
</tr>
</table>
<HR align="center" size="2" width="60%" />
<!-- data table -->
</div>
</f:view>
THANKS.
-LI solved this.
Since I was testing the action code only, I didn't define a navigation entry corresponding to the action string returned for this button:
<h:commandButton value="Add" style="height:21px; width:51px;font-size:8pt; font-color: black;" action="#{resourceBean.addAction}">
</h:commandButton>After I added a nav definition, it worked. I don't know why at this point. I suspect a key step in the lifecycle was pre-empted...someone else can probably explain why. If I get a chance to research it after I'm done with my project, I'll update this post.
Thanks.
-L -
Is a Servlet-Filter which serializes requests in the same user session ok?
The Servelt specification states that the Web-Application is itself responsible for synchronizing access to HttpSessions. It is from the serversite not possible to prevent multiple threads to access the same HttpSession (i.e. the user could always open a second window, retransmit a form etc). My assumption is that while this does not happen often it can happen and therefore I think each access to the HttpSession must be synchronized. For a further discussion see http://forum.java.sun.com/thread.jsp?forum=4&thread=169872 .
Concurrent programming is generally complicated and errorprone. At least in developing JSPs it is inconvenient and easy to forget. My Web-App uses often HttpSession and it can be used in different not predefined places, so I had the idea to implement a ServletFilter which serializes threads which happen in the same session. This involves certainly some overhead. However for the advantages of easier code maintains and higher consistency I am ready to pay this overhead.
My question is generally what you think of this approach and second whether the way I implemented the Filter works.
The Filter actually generates for each Request an HttpServletRequestWrapper which intercepts calls to getSession and on call aquires a Lock so that other threads have to wait for the same Session. The lock is released when the doFilter method of the Filter returns. So threads run concurrently until the first access to the Session and from there they are serialized until the end of the Request.
For the details I will give the code for the Filter and the Wrapper (that?s all the code needed except the ReentrantLock which is Doug Lea?s implementation http://gee.cs.oswego.edu/dl/classes/EDU/oswego/cs/dl/util/concurrent/intro.html )
the Filter
public class SessionThreadFilter implements Filter
public static final String MUTEXT_IN_SESSION_KEY = "org.jaul.filter.SessionThreadFilter.MUTEX";
//constructor, init, destroy methods do nothing
public void doFilter(ServletRequest reqIn,ServletResponse res,FilterChain filterChain)
throws IOException, ServletException
//if req not instanceof of HttpRequest don't do anything
if (!(reqIn instanceof HttpServletRequest))
filterChain.doFilter(reqIn, res);
} else
HttpServletRequest req = (HttpServletRequest) reqIn;
//We use a HttpRequestWrapper each time a user accesses
//through this
//Wrapper a Session is Lock is aquired. The filter method returns
//the lock if it exists is released
//each thread needs it's own wrapper so the wrapper itself
//doesn't have to be synchronized
SessionThreadRequestWrapper wrapper = new SessionThreadRequestWrapper(req);
try{
filterChain.doFilter(wrapper, res);
}finally{
ReentrantLock lock = wrapper.getLock();
if (lock != null && lock.holds() != 0)
lock.release(lock.holds());
the Wrapper
final public class SessionThreadRequestWrapper extends HttpServletRequestWrapper {
private ReentrantLock lock = null;
* Constructor for SessionThreadRequestWrapper.
* @param arg0
public SessionThreadRequestWrapper(HttpServletRequest req){
super(req);
* @see javax.servlet.http.HttpServletRequest#getSession()
public HttpSession getSession(){
return getSession(true);
* @see javax.servlet.http.HttpServletRequest#getSession(boolean)
public HttpSession getSession(boolean construct){
//this will get the session an the lock
HttpSession session = getLockFromSession(construct);
if (session == null) return null;
//get a lock on the mutex
try{
lock.acquire();
} catch (InterruptedException e){
throw new IllegalStateException("Interrupted while thread waiting for session");
//now we check again if the session is still valid
try{
session.getAttribute(SessionThreadFilter.MUTEXT_IN_SESSION_KEY);
} catch (IllegalStateException e){
//again we go recusively but first release the lock
lock.release();
lock = null;
return getSession(construct);
//after you got the lock you can return the session
return session;
* gets the lock from the session
* @param construct
* @return HttpSession
private HttpSession getLockFromSession(boolean construct){
//test if it is a new Session
HttpSession session = super.getSession(construct);
//if is null no session was realy requested
if (session == null) return null;
//otherwise try to get the lock if necessery construct it
//syncrhonized over session
synchronized (session){
//this migth throw an Exception if the session has been
//invalidated in the mean time
try{
lock = (ReentrantLock) session.getAttribute(SessionThreadFilter.MUTEXT_IN_SESSION_KEY);
if (lock == null){
lock = new ReentrantLock();
session.setAttribute (SessionThreadFilter.MUTEXT_IN_SESSION_KEY, lock);
return session;
} catch (IllegalStateException e){
//the session has been invalidated before we tried to get the
//lock we recursively call getLockFromSession
//( assumption checked with Jetty: if the session is invalidated
//and getSession is called on the thread a new valid session
// should is returend)
//I hope sometime you should get a valid session but I am not
//sure. This is crucial for breaking of the recursion
lock = null;
return this.getLockFromSession(construct);
/** used by the Filter to get the lock so that it can release it
ReentrantLock getLock(){
return this.lock;
}As stated I would be very thankful if you could check the code and give some commends.synchronized (session){Are you sure that the session instance returned by two
concurrent calls to getSession(...) are the same? I
think that tomcat for instance may return different
instances for the same "logical " session, which would
break your scheme I think... Thank you (I did not know that on Tomcat). The same thing could also occur if another filter wrapped the Session.
That's indeed a problem,which I have already adressed in another thread, but did not get an answer. ( http://forum.java.sun.com/thread.jsp?forum=33&thread=412380). The already cited thread http://forum.java.sun.com/thread.jsp?forum=4&thread=169872 adresses the same problem, but the discussion there ends with the recomandation that you should synchronize on HttpSession as I did it. Also in other forums I've read so.
However like you I've at least strong doubts in this approach, so now my question is on what should I than generally for any access in any web-app syncrhonize the access to Http-Session as demanded by the Servlet specs.
A few not realy satisfying answers:
Synchronize on the HttpSession itself: I think still the best approach, but as you say is it guaranteed that the same instance of an HttpSession is given to each Request (in one Session)?
Synchronized on the HttpServlet: This only works if no other servlet (or jsp) accesses in the session the value with the same key ( of course only if the session itself is threadsave). In case of ThingleThread it is not possible at all there can be multiple instances (you could use a static variable)
Holding the object to synchronize on in applicaton scope or session scope: This obiously doesn't help, because somehow you have to obtain the lock and at least there you need another synchronize.Holding in application socpe is slow a static variable lock would be better there.
Synchronize on some static variable: This will work, but is very slow (each request not only in the same session would synchronize on this).
Hold a map in application scope, which holds for each Session-key a lock: Is probably faster than the static variable thing. However the access and the management of the Map (removing of unused locks etc.- Mabe you could use a WeakHashMap to collect the locks for not used keys anymore) is time consuming too and again the map must be accessed syncrhonasly by all requests.
Syncrhonize on the Filter (only in my case): This is as slow as the static variable approach because each request will use the same lock the one instance of the Filter.
So synchronizing on the session is propably the best approach if the same attribute name is accesed by different servlets. However if you say that some Web-Containers return different HttpSession instances for the same Session (which is legal according to the specification) this of course does not work.
So I have realy no clue on what to syncrhonize than. Now help is not only neede on my Thread serialization filter but on my generally Servlet prgromming.
May be you could help me for another synchronization aproach.
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