jsp:usebean
Hi, I've got one question: I'd like to keep the constant string values in the single place to avoid the mess. So I have class Constants. let's say Constants have atrribute ATTR_MY_HANDLER="myHandler" I use then code like this session.getAttribute(Constants.ATTR_MY_HANDLER). This is OK In jsp side i'd like to store this bean to session using jsp:usebean directive. But as i see the parser gets confused at this point if i write smth like this jsp:useBean id=Constants.ATTR_MY_HANDLER scope="session" class="MyHandler" / It insists that id value is of type String and is placed between "". Is it possible to work around in nice way this situation or do I have to place this attribute to the session manualy? I do hate using same attribute in several places as it definetly leads to mistakes (i.e. I will not use jsp:useBean id="myHandler" scope="session" class="MyHandler" / Regards, Egidijus Drobavicius AB Vilniaus Bankas http://www.vb.lt tel. + 370 2 682706 Egidijus Drobavicius AB Vilniaus Bankas http://www.vb.lt tel. + 370 2 682706
Re: jsp:usebean
Nope, but this is not actually var name. This is key for the hashtable. And if i'd like to use SAME bean in two different places, i have to use SAME key to retrieve the bean, i.e. jsp:useBean id=myHandler scope=session class=MyHandler / jsp:useBean id=myHandler1 scope=session class=MyHandler / will create 2 objects and place them to session hash; As long as the project is maintained by few people, i'd like to have these var names defined to avoid mistyping and similar problems (you must admin, that it is much easier to get compile time error saying that ATTR_MY_HANDLEW is not defined than debug the code and find out that some person wrote getAttribute (myHandlew)) Maybe i'm wrong, but this is my attitude :) Regards, Egidijus - Original Message - From: Edwin Martin [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, May 31, 2001 11:21 AM Subject: Re: jsp:usebean Egidijus, I do hate using same attribute in several places as it definetly leads to mistakes (i.e. I will not use jsp:useBean id=myHandler scope=session class=MyHandler / You have a strange way of thinking, friend, You have to look at myHandler as a variable name. Do you store the name of a variable in a constant to clean up you code? Bye, Edwin Martin.
Re: Where's a servlet log?
It is $TOMCAT_HOME/logs/servlet.log. You can set this to any file by modifying server.xml. This file is self explanatory Note, that log file is started from scratch each time you restart the server so you must take care of old log your self (i did this by modifying tomcat.sh script. Regards, Egidijus Hi, When from a servlet i use the metthod HttpServlet.log(String, Exception) it apparentrly works but I cant' find the log file, neither in TOMCAT_HOME/log NOR ANYWHERE ELSE.. Where is it? or has the log method an empty implementation or what? Using tomcat 3.2 on winnt Thanks - dott. Luca Davanzo Insiel S.p.A. - Direzione Tecnica Via G. Pieri, 2 - 33100 Udine Italy tel. +39-0432-551971 * e-mail: [EMAIL PROTECTED] -
Re: tomcat+apache
WRONG If you include generated configuration in apache conf, starting apache before tomcat means that you dont use or you use outdated config of tomcat. Therefore you always have to start tomcat first and apache second. Regards, Egidijus - Original Message - From: David DELGRANCHE [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Wednesday, May 30, 2001 11:37 AM Subject: RE: tomcat+apache You just have to start apache before starting Tomcat! David. -Message d'origine- De: unplug [SMTP:[EMAIL PROTECTED]] Date: mercredi 30 mai 2001 10:35 A: tomcat-user Objet: tomcat+apache Hi all, Just install tomcat3.2.2 and mod_jk.so. However, when I restart tomcat and then apache, I found the following message in mod_jk.log [jk_uri_worker_map.c (335)]: jk_uri_worker_map_t::uri_worker_map_close, NULL parameter [jk_uri_worker_map.c (185)]: In jk_uri_worker_map_t::uri_worker_map_free, NULL parameters What do they mean?? How do I configure to remove the message?? Rgds, unplug
Re: java.lang.OutOfMemoryError
This is javaVM heap problem. You should increase heapsize. (e.g. JAVACMD=java -mx200M) Regards, Egidijus - Original Message - From: Srinadh Karumuri [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Friday, May 25, 2001 2:35 PM Subject: RE: java.lang.OutOfMemoryError If you are wondering where that magic number came from. Try 'java' at the command line. Then try 'java -X' for the help on non-standard options. You will probably find another flag or two useful. Sri At 02:22 PM 05/25/2001 +0200, you wrote: i think your problems can be solved be setting a higher maximum heap size. for example start tomcat by using java -Xmx256 ... to set heap size to 256 mb. michael -Original Message- From: Shailesh R Sah [mailto:[EMAIL PROTECTED]] Sent: Friday, May 25, 2001 1:01 PM To: [EMAIL PROTECTED] Subject: java.lang.OutOfMemoryError hi, i am giving details as follows of my site and problem Server configuration : HardWare: Pentium 800 MHz. 512 MB RAM 18 GB Hard Disk Global line server. Software Loaded: Red Had linux 6.2 Jdk1.2.2 for linux Jakarta-tomcat-3.2.1 A Seperate Server is there for Oracle. Total No. of JSPs on the server: 500Jsps Services Running: Apache, jakarta-tomcat Swap space: 2GB From the Last 2-3 weeks 1) The Tomcat is getting killed automatically. This is happening more frequently sometimes 4 times a day .The tomcat has to be started manually. The tomcat server is showing an error of out of memory(java.lang.OutOfMemoryError).Reports are attached in this document. 2) The top service is not running. . 3)Swap memory is 2GB What might be the possible possible reason??? Is it that the tomcat cannot handle 500-600 Jsps?? Kindly help out as the website is business critical. (See below for error details) As the problem is occuring daily.I am drawing a lot of flak at office as being a staunch supporter of open source and collabarative s/w movement i went for linux/tomcat combination. And now my decision is being questioned.Can u tell me of any source on the basis of which i can present the case of linux/tomcat combination or sites using lots of jsps(500-600) I am giving below the error coming in the tomcat console. java.lang.OutOfMemoryError: at java.io.InputStreamReader.init(InputStreamReader.java:86) at java.io.InputStreamReader.init(InputStreamReader.java:55) at java.io.FileReader.init(FileReader.java:35) at _0002findex_0002ejspindex_jsp_3._jspService(_0002findex_0002ejspindex _jsp_3.java:634) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:126) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at org.apache.jasper.runtime.JspServlet$JspServletWrapper.service(JspSer vlet.java:174) at org.apache.jasper.runtime.JspServlet.serviceJspFile(JspServlet.java:2 61) at org.apache.jasper.runtime.JspServlet.service(JspServlet.java:369) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at org.apache.tomcat.core.ServletWrapper.handleRequest(ServletWrapper.ja va:503) at org.apache.tomcat.core.ContextManager.service(ContextManager.java:559 ) at org.apache.tomcat.service.connector.Ajp12ConnectionHandler.processCon nection(Ajp12ConnectionHandler.java:156) at org.apache.tomcat.service.TcpWorkerThread.run(PoolTcpEndpoint.java:36 6) at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java :411) at java.lang.Thread.run(Thread.java:475) java.lang.OutOfMemoryError: at org.apache.tomcat.util.MimeHeaders.init(MimeHeaders.java:133) at org.apache.tomcat.util.MimeHeaders.init(MimeHeaders.java:141) at org.apache.tomcat.core.ResponseImpl.init(ResponseImpl.java:96) at org.apache.tomcat.service.http.HttpResponseAdapter.init(HttpRespons eAdapter.java:91) at org.apache.tomcat.service.connector.AJP12ResponseAdapter.init(Ajp12 ConnectionHandler.java:433) Thankx shailesh Srinadh Karumuri Senior Programmer/Analyst Business Apps. BBN Technologies (Verizon) Ph:(617)873-2841
Re: ===Session Question===
Use singleton. The way you described in your previuos design is not
singleton, singleton means one instance per application, your way was just
static class.
The basic idea would be smth like this
public class MySingleton {
private MySingleton() {}; // constructor MUST be private
private myInstance MySingleton; // this is your object;
public MySingleton getInstance(){
if (mInstance==null) mInstance=new MySingleton();
return mInstance;
}
}
From your code to get to this object you will use MySingleton
obj=MySingleton.getInstance();
Hope this will help
Regards,
Egidijus
- Original Message -
From: anil [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: Wednesday, May 23, 2001 4:51 AM
Subject: Re: ===Session Question===
Hi Warren,
Thanks for the magic to destroy the session object when the response is
delivered to client. That's the idea. I have some attributes that I do not
want
to go away as long as tomcat lives but need to have the freedom to change.
some
to live only for the request.
Like say that I have a object graph like salesman list that does not
change very
often. I want to keep them as context attribute. But on the
customerDetailDisplay I want to keep the customer for the one single
request
only where I got request for the CustomerDetail information.
With Jserv, I used to keep them in a singleton (so called application
objects)
. Now with Tomcat 3.2.1 + Jboss 2.1, the salesman list might change once
in
awhile (so that does not qualify as static type object), but it will stay
the
same for long period of time.
for recap:
1. object graph that might change once in awhile, but will used by
different
servlets
(hope to keep them as context session object) - how???
getContext.setAttribute(me,myGlobalObject);???
2. object graph that should live only for the request. OK:
request.setAttribute(oh!my,myRequestObjet);
next line always will be:
getServletConfig().getServletContext().getRequestDispatcher(page).forward();
idea is to have the request hit the servlet Controller first and then go
to the
view.
How do you guys handle situation like this in tomcat??
thanks
anil
Warren Crossing wrote:
hi anil,
i hope i've got your intention, you want to pass an object graph from
servlet1 to servlet2. tomcat provides session management through
request.getSession().setAttribute() these objects are accessible for the
duration of the session. If you only want the object graph to live for
the
lifespan of a single request then use request.setAttribute() and it will
automatically destroy() when the response is returned to the
tomcat-request-interceptor-responder-web-server-thingy ( i think that's
its'
technical name ) ;
warren.
Re: Session vs Beans
I think bean is much more clear approach. As i understood you have 2 ways -- store items directly to hashtable or store javabean and all you items into this bean. If you choose the first way the hashtable of the session would contain pretty much of your crap and in case you want to dump all of it you will run into problems which of these items are necessary for you and which were placed by some other bean/jsp or so on. If you use your own bean with a scope set to session (actually this would place your bean to the _same_ hashtable of session object), you will have all your form based valued concentrated in one single bean and that data will be encapsulated. When looking at performance and memory consumtion issues, the difference will me so miserable that even computer would not be able to distinct :) Regards, Egidijus - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, May 21, 2001 3:17 PM Subject: Session vs Beans Last week I proposed this question to the discission group: I am currently writing a pretty complex data entry HTML page for an application. The HTML has 7 different frames where data is input, one represents the master table and the others detail tables. I am trying to come up with a way to keep all of the data entered into each frame for updating the database (I want to update all the records in one transaction). There some obvious ways of doing this as with invisible fields on the master frame, and URL rewriting (cookies are out in this case) but I have also been looking into using the Session object. I know the object is used for shopping carts on commercial web sites but would it be a good to use it to keep all the input values for various input forms? There will be from 40 - 50 items of data stored in the session object and a user will only be able to have one form at a time? The unamious (and very helpful) response was yes use a session object. Now however, I have learned to use Java Beans in JSP and was wondering, is it better to use a session object or a Java Bean with the scope set to session to store these values? Thanks for you help Jeff Sulman
Re: Apache 1.3.19/Tomcat 4.0B5 conf
Hey, why do all your messages require chinese simplified char set? Can you disable this? - Original Message - From: egcs12md To: [EMAIL PROTECTED] Sent: Friday, May 18, 2001 3:34 AM Subject: Apache 1.3.19/Tomcat 4.0B5 conf Has someone successfully use Apache 1.3.19 with Tomcat 4.0b5 in WinNT/Win2K,and how can I use Tomcat-Apache Engine in %APACHE_HOME%\htdocs and all it's subdirectories ?
POST File: weird situation
Hello, I've ran into strange a bit situation: i have to do file upload. I did this and there is no question about that. The question is: i want first verify all the data and then ask the user to confirm it. So i get all inputs and do my check, then i'd like to generate a page that has only 2 buttons submit and cancel, and on submit upload the data. Here the problem comes. Is it possible to do that? I mean is there any way of doing such a form? There is no attribute hidden for input type file. Is there any way at least to set the value for this field? I've tried using value=myfilename, but this does not work. The problem can be solved by parsing all the data in the POST data request. But this stream contains useful data and I can not later retrieve it. E.g stream has some_my_value one_more_value file_itself value value_again another_file I am not sure if the request can be served without knowledge about fields value and value_again. However, to get these values i must skip maybe useful information. I can not use temporary files for storing it. Huh, if someone got what I am talking about, could you please share your possible ideas with me. Thanks, Egidijus
Re: Posting multipart/form-data
Yes, I've dealt with similar problem. First, you have to use POST method to upload files; Second, you have to implement your doPost method to handle that kind of request. All parameters, files etc are provided via input stream. If you dont read single byte from that stream, you get this 404 error. And most annoying thing is that Tomcat has a bug in ServletInputStream and readLine does not actually read from the stream and says that there are no bytes available. What i did -- i did my own readLine method and read byte by byte from the stream. Steps that you have to do reading request: 1. retrieve boundary string String contentType = req.getContentType(); int ind = contentType.indexOf(boundary=); 2. parse the input stream You have to play with that a bit, see what the stream looks like. When sending a response, set content type to text/html use HttpServletRequest.getContentLength() to see the length of the content and avoid upload of extremely large files. Egidijus - Original Message - From: Brandon Cruz [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Friday, May 11, 2001 12:25 AM Subject: Posting multipart/form-data When I try to specify enctype=multipart/form-data, the page just goes blank and IE says that it can't find server. Anyone know why this might happen? Brandon
Re: Apache with Tomcat configuration
Apache and tomcat talks on port 8007 using Ajp12 protocol. See if after tomvat startup if there is line like Ajp12ConnectionHandler on 8007 Then try to telnet to this port (telnet yourhost 8007) In tomcat console you shoud see exception Maybe you set wrong communication either on apache side or on tomcat. Ajp must use same port on both sides. Egidijus - Original Message - From: Rao, Viswanatha [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, May 10, 2001 11:19 PM Subject: Apache with Tomcat configuration When I configure Apache with Tomcat and invoke example Servlet, Apache does not communicate the request to Tomcat. However Tomcat on port 8080 brings the servlet. If I change the Apache port from default 80 to any other port, then Apache and Tomcat talk to each other and servlet can be invoked through Apache. Can anyone help me? Regards Vishwa
Does tomcat undestant static classes?
I use one class as a collection of data items, such as public static final String tmpDir="/u/somedir" When I use this under W2000, it works. Under UNIX (SCO 506) i get java.lang.IllegalStateException: Can't happen - classname is null, who added this ? at org.apache.tomcat.core.ServletWrapper.loadServlet(ServletWrapper.java, Compiled Code) at org.apache.tomcat.core.ServletWrapper.init(ServletWrapper.java, Compiled Code) at org.apache.tomcat.core.Handler.service(Handler.java, Compiled Code) at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java, Compiled Code) at org.apache.tomcat.core.ContextManager.handleStatus(ContextManager.java, Compiled Code) at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java, Compiled Code) at org.apache.tomcat.core.ContextManager.service(ContextManager.java, Compiled Code) at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java, Compiled Code) at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java, Compiled Code) at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java, Compiled Code) at java.lang.Thread.run(Thread.java, Compiled Code) Could anyone explain what is this? Thanks a lot Egidijus DrobaviciusAB Vilniaus Bankashttp://www.vb.lttel. + 370 2 682706
Re: jsp and servlet
According to JSP specification, objects with a scope application are stored to context object's hashtable which is supposed to be one for the application. This means that if you store object once (jsp:useBean id=myBean class=myclass scope=application/) each time later it will not be created and useBean will return the same object. From the servlet for retrieval i use context (i have HTTPServlet, and do this.getServletContext().getAttribute(myBean)) - Original Message - From: Andrea Mari [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, May 10, 2001 4:56 PM Subject: jsp and servlet Hi, in a jsp page I have an object with scope application. Can I use this object from a servlet? Thanks Andrea
SCO Unix: Apache and Tomcat do not cooperate
Hello, I've moved from win2000 to SCO Unix and faced problems: 1. I was getting 403 Forbiden error. After I've changed all tomcat files to nouser:nogroup, this seems to be fixed 2. I've included tomcat-apache.conf to my httpd.conf, and if I access http://myhost/examples/ i see those pages; If I access servlets, they come occasionaly (meaning that I have to press few times refresh to get them working) If I am to view *jsp examples, i get blank pages and error in console saying 2001-05-08 11:41:24 - Ctx( /examples ): IOException in: R( /examples +/jsp/num/numguess.jsp + null) Connection reset by peer This happens both on IE and Nescape and as i said before, i see only blank screen. jasper.log says 01-05-08 11:41:13 - ServletPath: /jsp/num/numguess.jsp2001-05-08 11:41:13 - PathInfo: null2001-05-08 11:41:13 - RealPath: /var/opt/K/SCO/Unix/5.0.6Ga/usr/local/jakarta-tomcat-3.2.1/webapps/examples/jsp/num/numguess.jsp2001-05-08 11:41:13 - RequestURI: /examples/jsp/num/numguess.jsp2001-05-08 11:41:13 - QueryString: null2001-05-08 11:41:13 - Request Params: 2001-05-08 11:41:13 - Classpath according to the Servlet Engine is: /var/opt/K/SCO/Unix/5.0.6Ga/usr/local/jakarta-tomcat-3.2.1/webapps/examples/WEB-INF/classes I use JServ module that came along with apache for tomcat-apache communication. Egidijus DrobaviciusAB Vilniaus Bankashttp://www.vb.lttel. + 370 2 682706
