Re: How to display the size of an Collection attribute of a bean?
At 03:33 AM 4/10/2001, you wrote: I want to display the size of an Collection attribute of a Bean using Struts taglibs. I can use scriptlet but are there any other ways to do that? Regards, Thai Based on a response from [EMAIL PROTECTED] to a bug I filed, it appears you can use the bean:size tag to do what you want. Here is a snipped from the bug tracking system that should illustrate getting the number of elements into a bean. For your problem, you would then use bean:write to display this item count in your HTML (instead of using logic:equal to check the size). ! --- Additional Comments From [EMAIL PROTECTED] 2001-03-30 16:20 --- ! I had a similar problem awhile ago and Craig created the bean:size tag. This ! can be used along with logic tags to do what you want. ! ! bean:size id="numlineitems" name="userorderdetail" property="orderLineItems" ! scope="request" / ! logic:equal name="numlineitems" value="0" ! bean:message key="emptylist.noitemsinorder"/ ! /logic:equal ! logic:greaterThan name="numlineitems" value="0" ! ... ! /logic:greaterThan
Re: Getting the html:errors tag to display on multiple lines
Just specify the property attribute of the html:errors tag. So, for
example, in your validate function you might have something like:
errors.add("roles", new
ActionError("error.reqaccess.role.invalid"));
to indicate an error in the "roles" field. Using:
html:errors property="roles"/
in your JSP will show only the errors associated with the roles
field. Repeat this for as many fields as you have and use the appropriate
parameters to errors.add(), and you should be able to place errors in the
appropriate locations.
Mike
At 02:12 PM 3/13/2001, you wrote:
Hello,
I guess this is kind of a trivial question, but I'm having a problem getting
the
"html:errors" tag to display on multiple lines for multiple errors. Am I
overlooking
something obvious, or do I have to use the iterator tag and parse the errors
myself if
I want them on separate lines? If you could respond directly to me at:
[EMAIL PROTECTED]
Thanks
Justin
Mismatch Between html:options and logic:iterate
Am I the only one who finds it odd that while both logic:iterate and html:options take a "collection" attribute, one expects a run-time expression that evaluates to a Collection and the other takes a String that names a bean in some scope that is a Collection? Shouldn't these two tags play according to the same rules when it comes to identically named attributes? Should I file a bug for this? Should one behavior "win-out" over the other? In my opinion, the behavior of naming bean with a String attribute feels the most "Struts like". Unfortunately, changing things one way or the other will break code, but better to do so before cutting a release than after. Mike
Re: Question about struts application model (DataSource, Business Log ic beans)
I resolved this by creating two pieces: First is a class in your business logic package that manages the context required by the business logic beans. This class should be a Singleton and should manage access to resources needed by your business logic beans such as configuration parameters and your DataSource. I modeled my context object after the Servlet session API, but you could make it much more structured if you like. Second, depending on your servlet environment, create some mechanism to initialize your application context object. Using Tomcat, you could do this using something like the DatabaseServlet from the Struts example. In this case, your DatabaseServlet gets started by the servlet container and it initializes your application context object (using servlet initialization parameters, things like a GenericDataSource object, etc.). Now when your business logic beans are called, they retrieve the application context, ask it for a DataSource, and use it to get a connection. When you decide to re-implement your application as a two-tier Client/Server application with a Swing front-end, all you need to do is implement some alternate method for your application context object to be initialized and your business logic beans are shielded from the change. I'm not sure this is the best way to decouple your layers, but it's what I've come across so far. Mike At 12:22 PM 3/12/2001, you wrote: Hi, I'm using Struts for a new application that I'm developing. I have a question about the separation between the Action classes and the Business Logic beans. My Business Logic beans are making database accesses to manipulate the underlying data model. I am planning on using the struts db connection pool, which is supplied through the DataSource. My problem is that access to the DataSource is through the servlet.getDataSource() call. How do I make the Business Logic beans unaware of the servlet/http layer (as suggested in the developers guide) while still making the DataSource available to the Business Logic beans? Do I have to pass a reference to the DataSource on every call the Business Logic beans (not an option that I like), or is there a cleaner way to do this? I also have a similar issues with logging services. I believe that a common way to solve this problem is to bind the DataSource to a jndi service. I am using tomcat 3.2.1, and I don't believe that this functionality is supplied in either Tomcat or Struts. Thank You, Carles
Business Object Bean Persistence Strategies
What strategies or patterns do people use to manage persistence of business object data in a Struts application when there is no EJB layer and there is a desire to keep the business objects as independent of the web portion of the application as possible? Do you use the Struts DataSource and pass either it or a Connection as a parameter to bean methods that take responsibility for managing persistence? Do you follow the J2EE blueprint and create separate Data Access Objects to support persistence? Are you using an open-source framework to manage persistence? This seems like a common problem, but I haven't seen much talk about common solutions. Mike
Re: URGENT RE: token issue in hyperlink
Here is what I do in a similar situation:
html:link paramId="role" paramName="role"
page='%="/user/saveUser.do?action=Removeorg.apache.struts.taglib.html.TOKEN="
+
session.getAttribute("org.apache.struts.action.TOKEN")%'
Removenbsp;Role /html:link
It's ugly, but it works for now. Notice the single quotes around the page
argument. Very important or the JSP parser will get confused by the
embedded double quotes in the expression.
I've submitted an enhancement request (Bug #874
http://nagoya.apache.org/bugzilla/show_bug.cgi?id=874) to add an optional
parameter to the html:link tag that would do this magic without the need
for the expression shown above. If I can get Struts set up to build
locally, I will probably give implementing this a go myself so I can submit
a patch rather than just a request. Using the link above, you can vote for
the implementation of this enhancement.
Mike
At 07:43 AM 3/7/2001, you wrote:
Hello,
I have posted this before. This is extremely urgent for me. I know that
the token support exists for posting Form(s). How can i ensure that this
same token will be issued to a hyperlink so that i can validate that the
user will click on the hyperlink only once ? Any help is greatly
appreciated. Thanks a lot.
cheers,
Amar..
-Original Message-
From: Nanduri, Amarnath [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, March 06, 2001 2:23 PM
To: '[EMAIL PROTECTED]'
Subject: token issue in hyperlink
Hello All ,
I am using the Action class saveToken() method to ensure that a token
is created and set (so that the user has proper screen flow). My question is
... how can i add this token to a hyperlink ?
I have a hyperlink in a jsp page, which takes me to a different Action
class. I am checking for this token in the second Action class. Any help is
greatly appreciated. Thanks.
cheers,
Amar..
RE: URGENT RE: token issue in hyperlink
I can't speak about the address bar (different browsers probably behave differently), but if you aren't seeing it in the generated source then there is a problem. To confirm, you don't see the org.apache.struts.taglib.html.TOKEN=4bb7c9e6084fbf88acc2aa976ea9e3 string in your generated hyperlink href? Do you see the "org.apache...TOKEN" part but not the hex string after the equals sign? If so, maybe you are not doing a saveToken(request) in an Action before you forward to your JSP page. Mike At 10:58 AM 3/7/2001, you wrote: Mike, Thanks a lot. It works. I did vote for this enhancement to take place. One question i have is...how come i don't see the session id in the address bar ? Is it because GET limits the number of characters that can be kept in the Address Bar ? Also i did not see the sessionid when i did a 'view source' and checked the source of my generated page. Clarification on this issue is greatly appreciated. cheers, Amar..
Re: Problem in Struts example (struts-example.war)
Is this really true? I have an Action that doesn't define an input attribute, but does specify a request scope ActionForm. According to the log messages, Struts creates an instance of the form and stores it under the appropriate key before calling my Action.perform() method. In addition, the code I have to handle the form == null case never seems to get called. At 11:40 PM 3/4/2001, Craig McClanahan wrote: The "form" object passed to an Action will indeed be null if the struts-config.xml file does not define an "input" attribute for this particular action. Although that is not the case currently for the Struts example app, consider me an old paranoid programmer about double checking the "it can never happen" cases ... :-) Mike
Re: form initialization using session
The way this is typically handled is to use an Action to populate the bean. So instead of linking your user directly to the JSP page, you link them to an Action. This Action typically loads the bean and then returns the success mapping, which, in struts-config.xml, you've mapped to the JSP that displays the values from the bean. The example application that comes with struts shows how to do this. The walking tour that accompanies the example explains it better than I have. Look at the relationship between EditSubscriptionAction.java, subscription.jsp, and SaveSubscriptionAction.java. Mike At 11:46 AM 2/27/2001, you wrote: Hi all, I am working on an application where form fields need to default to values that depend on the user's profile, which is stored in the session. Unfortunately, it seems like struts forms are created automatically without any hooks that allow access to the session to initialize these fields. The only thing that I can think of is to have our application proactively place the forms into the session with values initialized, possibly to have the form page link through an action which creates and initializes the form. However this abandons the utility of having struts automatically create the forms for us - one of the many nice things about struts! This seems to me like it would be a common problem. Does anyone have a good solution for it? Cheers, Simon.
Re: My weblogic 5.1 sp8 isn't able to find web-app_2_2.dtd
No, this doesn't work in Tomcat 3.2.1 either (at least, not in all
cases). Here's my situation:
Normally, I am behind a firewall that prevents direct connection to the
Internet. I can't even resolve external domain names. Now when I start up
Tomcat with the struts-example deployed (using the Feb 22 nightly build), I
get the following exception in my servlet.log:
2001-02-23 09:46:44 - path="/struts-example" :action: Initializing
configuration
from resource path /WEB-INF/struts-config.xml
2001-02-23 09:46:47 - path="/struts-example" :action: null -
org.xml.sax.SAXPars
eException: External entity not found:
"http://java.sun.com/j2ee/dtds/web-app_2_
2.dtd".
at com.sun.xml.parser.Parser.fatal(Parser.java:2817)
at
com.sun.xml.parser.Parser.externalParameterEntity(Parser.java:2506)
at com.sun.xml.parser.Parser.maybeDoctypeDecl(Parser.java:1137)
at com.sun.xml.parser.Parser.parseInternal(Parser.java:481)
at com.sun.xml.parser.Parser.parse(Parser.java:284)
at javax.xml.parsers.SAXParser.parse(SAXParser.java:155)
at javax.xml.parsers.SAXParser.parse(SAXParser.java:77)
at org.apache.struts.digester.Digester.parse(Digester.java:716)
at
org.apache.struts.action.ActionServlet.initServlet(ActionServlet.java
:1390)
at
org.apache.struts.action.ActionServlet.init(ActionServlet.java:469)
at javax.servlet.GenericServlet.init(GenericServlet.java:258)
at
org.apache.tomcat.core.ServletWrapper.doInit(ServletWrapper.java:317)
at org.apache.tomcat.core.Handler.init(Handler.java:215)
at
org.apache.tomcat.core.ServletWrapper.init(ServletWrapper.java:296)
at
org.apache.tomcat.context.LoadOnStartupInterceptor.contextInit(LoadOn
StartupInterceptor.java:130)
at
org.apache.tomcat.core.ContextManager.initContext(ContextManager.java
:491)
at
org.apache.tomcat.core.ContextManager.init(ContextManager.java:453)
at org.apache.tomcat.startup.Tomcat.execute(Tomcat.java:195)
at org.apache.tomcat.startup.Tomcat.main(Tomcat.java:235)
2001-02-23 09:46:47 - path="/struts-example" :action: Mapping for servlet
'actio
n' = 'null'
2001-02-23 09:46:48 - path="/test" :jsp: init
2001-02-23 09:47:46 - path="/struts-example" :jsp: init
2001-02-23 09:48:08 - path="/struts-example" :jsp: init
When I am connected to the Internet, here is what I get instead:
2001-02-23 09:54:17 - path="/struts-example" :action: Initializing
configuration
from resource path /WEB-INF/struts-config.xml
2001-02-23 09:54:24 - path="/struts-example" :action: Process
servletName=action
, urlPattern=*.do
2001-02-23 09:54:24 - path="/struts-example" :action: Mapping for servlet
'actio
n' = '*.do'
2001-02-23 09:54:24 - path="/test" :jsp: init
2001-02-23 09:54:43 - path="/struts-example" :jsp: init
2001-02-23 09:55:12 - path="/struts-example" :jsp: init
So for some reason, Tomcat isn't looking at the local web.dtd file in the
tomcat\conf directory. Do I have something configured incorrectly?
Mike
At 09:19 AM 2/23/2001, you wrote:
Please, excuse me if I am not correct. Your application try to get a file
web-app_2_2.dtd from java.sun.com/j2ee/dtds site. And for some reason this
site was unreachable
(http://java.sun.com/j2ee/dtds/web-app_2_2.dtdhttp://java.sun.com/j2ee/dtds/web-app_2_2.dtd)
- see below highlighted with blue color. As Craig M. explained, in this
case Weblogic has to read its own local file. But it did not!??? Maybe
this works only on Tomcat.
Maya
Pablo Estades Fernndez wrote:
Hi all,
I'm using this great framework for a few weeks and it
seems fantastic, but I have experimented a problem
with the last nightly versions;
Weblogic doesn't find the http://http://
java.sun.com/j2ee/dtds/web-app_2_2.dtd.
I already have read the Vincent Massol reply to this
problem, telling we have to change
!DOCTYPE web-app PUBLIC "-//Sun Microsystems,
Inc.//DTD Web Application
2.2//EN"
"http://java.sun.com/j2ee/dtds/web-app_2_2.dtdhttp://java.sun.com/j2ee/dtds/web-app_2_2.dtd"
to
!DOCTYPE web-app PUBLIC "-//Sun Microsystems,
Inc.//DTD Web Application
1.2//EN"
"http://java.sun.com/j2ee/dtds/web-app_2_2.dtdhttp://java.sun.com/j2ee/dtds/web-app_2_2.dtd"
and this doesn't works for my.
With the 02/05 version doesn't happen, but fails the
redisplay of a password field which I need it.
I've tryed with the earlier nightly version (02/16)
and also fails.
Do you any suggestions?
Thanx a lot!
PD: This this the exception:
resolveEntity('-//Sun Microsystems, Inc.//DTD Web
Application 2.2//EN', 'http://http://
java.sun.com/j2ee/dtds/web-app_2_2.dtd')
Not registered, use system identifier
vie feb 23 15:48:27 CET 2001:E
WebAppServletContext-uni2 action: null
java.net.NoRouteToHostException: Host unreachable: no
further information
at
java.net.PlainSocketImpl.socketConnect(Native Method)
at
java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:312)
