Re: [OT] JDBC confusion
The preferred way of doing this is to use connection pooling. The primary reasons are scalability, speed and simplicity. If you have 5,000 people using your app at the same time, by your method you will have to have 5,000 connections to the database (one per user) stored in the various sessions. However, those 5,000 connections aren't being used at the same time: each one probably has only an infrequent burst of activity on it. This is where connection pooling comes in. The connection pool has n connections (say, 10 - 20) that are kept active. When an application needs a connection to the database, it checks one out from the pool (it doesn't need to create and open one because it is already created and open -- a win in terms of speed), uses it and closes it just any other database connection. However, when it closes the connection, the connection isn't really closed; it's just returned to the pool. So, the application developer is hidden from the complexity of actually creating the connections to the database, making sure they are in good working order, etc. To get started with connection pooling in Tomcat, see http://jakarta.apache.org/tomcat/tomcat-4.1-doc/jndi-datasource-examples-howto.html And check out the mailing list archives: the question of setting up connection pooling comes up very frequently. HTH Andrew P.S. Depending on the size/complexity of your project, you might be better off using an O/R mapping tool like OJB (http://db.apache.org/ojb/) or Hibernate (http://hibernate.bluemars.net/) instead of using JDBC directly. john-paul delaney wrote: Hello List... newbie question coming up: If I set up a jdbc connection object in one servlet, do I have to close it each time or can the same connection be re-utilized by other servlets each using a different sql statement (perhaps storing the connection as a session attribute?). Is there a significant resource saving by not creating a JDBC connection object for each database access? I'm thinking of storing a connection for each user in the session, as opposed to pooling - primarily because I'm not sure how a database pool works nor how to set it up. Should I do a re-think on this? I'm using one postgresql 7.3.3 thanks /j-p. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Tomcat with Virtual hosting
Why do you need to forward the request from index.html to index.jsp? Can't you simply set index.jsp to be a directory index page (e.g., DirectoryIndex index.html index.jsp)? Abhinav Gautam wrote: Hi, I am having serious problems with Tomcat. It just happened that without any reason the web server stopped responding to JSP requests. I have restarted Tomcat and Apache several times, but when the index.html forwards the request to index.jsp, I get an error saying page not found. I have checked the server.xml and the httpd.conf files and everything seems to be fine. Also when I do netstat -ta the server seems to be listening on port 8007. I have virtual hosting set up in tomcat. There's one primary domain with an IP address and there are 2 other domains with a different IP (different from primary, but one IP for both of the other domains) set up on the same web server. Any help will be greatly appreciated. Thanks. Abhinav - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: tomcat5.0
WEB-INF has a special meaning to a servlet container (e.g., Tomcat) and must be a top-level directory in your web application directory (in this case, it must be located at .../ROOT/WEB-INF). Download the servlet specification and take a look at section 9.5: http://java.sun.com/products/servlet/download.html Raicea Lavinia wrote: Hi, My name is Lavinia Raicea and I am a student. I am trying to learn about JSP2.0 and Servlets so I have installed Apache Tomcat 5.0 (Windows XP) and I took some documentation to run some servlet examples. I don't know what I am doing wrong but when I put the source code in the folder $installdir/webapps/ROOT/WEB-INF/classes it works. But when I do the same thing but in a subfolder of ROOT (.../ROOT/deploy/WEB-INF/classes) it doesn't work anymore.I think is something with my configuration of tomcat but I dont't seem to get it right. If you would be so kind and tell me where I am wrong I would be very grateful. Thank you very much, Lavinia - Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Tomcat Education Examples
I think what you're looking for is an application framework. There are a number of them at Apache: Struts: http://jakarta.apache.org/struts/index.html Turbine: http://jakarta.apache.org/turbine/index.html Tapestry: http://jakarta.apache.org/tapestry/index.html Cocoon: http://cocoon.apache.org/ Jetspeed: http://jakarta.apache.org/jetspeed/site/index.html All of the above projects have nice example templates. Donald Duquaine wrote: I understand that this list can be helpful to have our questions answered. And, that books seem not to be the most up todate means to acquire the most current practices and Tomcat (catalina) techniques. I learn best by examples and I have been a Tomcat user for several years. In all my google searching, I have not found a robust template example that has assisted me in creating my app. I am having to code from scratch. I have started over several times because my design was flawed for one reason or another, but I am making headway. My app is now in production. What I want most is to be part of a group that is focused on developing the end application. Tomcat is an important part of this development and this 'app-group' would need to recognize Tomcat's capabilities. How many others need an 'app-group'? or examples? Best Regards, Donald Duquaine Millennium Laboratories Inc. (813) 925-3871 voice (813) 925-3872 fax mailto:[EMAIL PROTECTED] http://www.mlabs-fl.com - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Tomcat Realm Example Problems
This error means that you directly referenced the login page. This is an annoyance with Tomcat security realms: you get authenticated, but since you weren't going anywhere in the realm, you get the HTTP Status 400 error. Rather than accessing the login page, simply access any page that is protected by the realm. Tomcat will bounce you to the login page and, following successful authentication, will bounce you to the page you were originally trying to access. Andrew -Original Message- From: Brown, Melonie S. - Contractor [mailto:[EMAIL PROTECTED]] Sent: Wednesday, November 20, 2002 12:04 PM To: [EMAIL PROTECTED] Subject: Tomcat Realm Example Problems Running Tomcat 4.1.12 on Windows 2K... I try running the jsp security realm example and get the following error after logging in: HTTP Status 400 - Invalid direct reference to form login page type Status report message Invalid direct reference to form login page description The request sent by the client was syntactically incorrect (Invalid direct reference to form login page). Any suggestions? This is from the example code provided. I have made no changes. Melonie Brown -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED] -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
RE: Getting 4.0.4
See http://jakarta.apache.org/builds/jakarta-tomcat-4.0/archives/ for past versions of Tomcat. Be aware, though, that Tomcat 4.0.4 and 4.0.5 have security vulnerabilities. See http://jakarta.apache.org/site/news.html for 9Oct2002 and 24Sep2002 for more information. Andrew -Original Message- From: Andoni [mailto:[EMAIL PROTECTED]] Sent: Tuesday, November 19, 2002 5:53 AM To: Tomcat Users List Subject: Getting 4.0.4 Hello, I work with OpenVMS and as such I want to work with the exact version of Tomcat for my Win2k workstation that I am using on the live server. Is there any way I can download Tomcat 4.0.4 (instead of 4.0.6) from the tomcat site? Thanks, Andoni. -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED] -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
RE: Page caching in 4.0.x
I'm having a similar problem (also using struts) in Tomcat 4.0.2. Scenario: I have a search page that performs a search and brings up a results page. On the results page, you can click on a hyperlink to get additional information about an element of the search. If you have clicked on a hyperlink and are on the page with the additional information about an element of the search and you click the back button of the browser, you get the message [in IE] Warning: Page has expired. I've found that the problem (for me) is realm security. Using the JDBCRealm, I get the above message when I use the back button; however, if I modify the realm such that it is not protecting my search and results pages, I no longer receive the warning when I use the back button. I'm guessing that the realm filter turns caching off for all pages in the realm. Watching the access logs, I've noticed that even for jsp pages in a realms, the browser goes back to the server and reloads the page, rather than using a cached copy of the page (as it does for pages not in the realm). Does that sound correct? Is there some way to disable turning the caching off? Thanks Andrew -Original Message- From: Eric Hansen [mailto:[EMAIL PROTECTED]] Sent: Friday, November 08, 2002 11:36 AM To: Tomcat Users List Subject: Page caching in 4.0.x Hello, I'm in the process of migrating a Struts-based web application from Tomcat 3.x to Tomcat 4.0.6. Without making any changes to the 'Action' servlets or the JSP pages, my form based pages are now giving the 'Page has Expired' message and forcing me to 'refresh'. They never did this with Tomcat 3.x My JSP pages have no expire dates set in the header nor any other header directives relating to caching (that I am aware of) Can anyone venture an explanation to this change? and maybe a solution... Thanks, Eric Hansen -- To unsubscribe, e-mail: mailto:[EMAIL PROTECTED] For additional commands, e-mail: mailto:[EMAIL PROTECTED]
TC authentication: j_security_check and url-pattern
I'm using form-based authentication in Tomcat 4.1.12 -- it works great! However, I have two questions about Tomcat authentication: 1) Many end-users bookmark the login page. So, the first time they login everything works as expected, but when they use the bookmark, they get the invalid reference form login page. Is there a way to specify a page for Tomcat to redirect the user to after authentication in the case that the user goes directly to the login page? I've seen this question come up in the archives, but I haven't seen a solution other than user education :). The closest thing I've seen is http://nagoya.apache.org/bugzilla/show_bug.cgi?id=8976 Does anyone know the status of this enhancement? Is there some other workaround? 2) I have some images I want to use on the login page. If I use url-pattern/*/url-pattern in the web.xml file, the pictures are blocked from being displayed. In the web.xml file, I would like to say, 'protect all files except the images used on the login page'. Is there a way to do this; that is, rather than saying, 'protect x, y and z', is it possible to say, 'protect everything except a, b and c'? I haven't seen anything like this in the documentation. Thanks Andrew -- To unsubscribe, e-mail: mailto:tomcat-user-unsubscribe;jakarta.apache.org For additional commands, e-mail: mailto:tomcat-user-help;jakarta.apache.org
RE: Pager Tag Library - Broken in 4.1.12
See the following thread which explains why the problem arises and how to
fix it.
http://www.mail-archive.com/tomcat-user;jakarta.apache.org/msg67093.html
To the above solution, I made two additional changes because
1) the list of duplicated parameters on the url grew as it was paged -- e.g.
url?a=ba=ba=ba=b... (I was using the pg:param tag)
2) after paging in list1 and going to list2 where I expected to begin paging
on the first page, I would begin paging on the page number of list1.
The modified method for the com.jsptags.navigation.pager.PagerTag class is
below.
HTH
Andrew
public int doStartTag() throws JspException {
if (url == null) {
url = ((HttpServletRequest)pageContext.getRequest())
.getRequestURI();
int i = url.indexOf('?');
if (i != -1)
url = url.substring(0, i);
}
System.out.println(url = + url);
itemCount = 0; // modified
params = null; // modified
offset = 0; //modified
String tmp =
pageContext.getRequest().getParameter(id+OFFSET_PARAM);
if (tmp != null) {
try {
offset = Integer.parseInt(tmp);
if (offset 0)
offset = 0;
if (isOffset)
itemCount = offset;
} catch (NumberFormatException e) {
}
}
pageNumber = pageNumber(offset);
pageNumberInteger = new Integer(1+pageNumber);
pageContext.setAttribute(id+PAGE_NUMBER, pageNumberInteger);
pageContext.setAttribute(id+OFFSET, new Integer(offset));
pageContext.setAttribute(id+MAX_ITEMS, new
Integer(maxItems));
return EVAL_BODY_INCLUDE;
}
-Original Message-
From: Robert Biernat [mailto:RobertB;oopl.com.au]
Sent: Friday, November 08, 2002 2:54 AM
To: '[EMAIL PROTECTED]'
Subject: Pager Tag Library - Broken in 4.1.12
Hi,
I'm trying to use the Pager Tag Library found at
http://jsptags.com/tags/navigation/pager/pager-taglib-1.1.html
http://jsptags.com/tags/navigation/pager/pager-taglib-1.1.html
in my webapp thats running on 4.1.12 and it appears that 4.1.12 has
something in it which prevents the tag from working correctly. Basically
when the page is first rendered it looks fine, until you try and page
through the records in which case it doesnt work.
Whats even worse is even after closing the browser and going back to the
page, instyead of the tag rendering correctly it stays in the samne state it
was at before the broswer was closed. Its as if the tag lib is being cached
somewhere.
Does anyone know wether 4.1.12 introduced anything that new that could be
causing it.
Also in this new version I sometimes get jasper exceptions after I redeploy
an application, but this goes away usually if i jhust hit refresh in the
browser.
I tested it in Tomcat 4.0.X and it works fine.
Has anyone else experienced this problem?
Thanks
Rob
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