ModelDriven, Preparable and SessionAware do not work with Spring
Hi All,
I have been playing with Struts 2.0 sample application, struts-blank, and
integrates it with Spring 2.x. So far, I have not been having great success
with it.
I have followed all the steps needed to integrate Struts 2.0 with Spring 2.0.
Here is what I have done so far:
1) Included struts2-spring-plugin-2.0.6.jar, spring.jar,
struts2-core-2.0.6.jar and the dependent jars.
2) Modified the example.xml to include spring object factory:
!DOCTYPE struts PUBLIC
-//Apache Software Foundation//DTD Struts Configuration 2.0//EN
http://struts.apache.org/dtds/struts-2.0.dtd;
struts
constant name=struts.objectFactory value=spring /
package name=example namespace=/example extends=struts-default
default-interceptor-ref name=defaultStack/
action name=helloWorld class=helloWorld
result/example/HelloWorld.jsp/result
/action
action name=Login_* method={1} class=example.Login
result name=input/example/Login.jsp/result
result type=redirect-actionMenu/result
/action
action name=Menu class=Menu
result/example/Menu.jsp/result
/action
action name=* class=example.ExampleSupport
result/example/{1}.jsp/result
/action
!-- Add actions here --
/package
/struts
3) I have edited the spring applicationContext.xml
?xml version=1.0 encoding=UTF-8?
!DOCTYPE beans PUBLIC -//SPRING//DTD BEAN//EN
http://www.springframework.org/dtd/spring-beans.dtd;
beans default-autowire=autodetect
!-- === Interceptors
= --
bean id=timeLoggingAdvice class=advice.TimeLoggingInterceptor/
!-- === Advisor
== --
bean id=timeLoggingAdvisor class=
org.springframework.aop.support.NameMatchMethodPointcutAdvisor
property name=mappedNames
list
valueexecute/value
/list
/property
property name=advice
ref bean=timeLoggingAdvice/
/property
/bean
!-- == Spring Beans
= --
bean id=helloWorld class=example.HelloWorld singleton=false/
bean id=Menu class=
org.springframework.aop.framework.ProxyFactoryBean
property name=proxyInterfaces
valueexample.IMenu/value
/property
property name=interceptorNames
list
valuetimeLoggingAdvisor/value
/list
/property
property name=target
ref local=MenuTarget/
/property
/bean
bean id=MenuTarget class=example.Menu singleton=false/
/beans
4) Implemented ModelDriven, Preparable and SessionAware interfaces in
Menu.java:
package example;
import java.util.Map;
import org.apache.struts2.interceptor.SessionAware;
import com.opensymphony.xwork2.ModelDriven;
import com.opensymphony.xwork2.Preparable;
/**
* codeSet welcome message./code
*/
public class Menu extends ExampleSupport implements IMenu, ModelDriven,
Preparable, SessionAware {
private Map _session;
private User user;
public String execute() throws Exception {
return SUCCESS;
}
public Object getModel() {
return user;
}
public void prepare() throws Exception {
if (getSession().get(user) != null) {
user = (User) getSession().get(user);
} else {
user = new User();
}
}
public void setSession(Map session) {
_session = session;
}
public Map getSession() {
return _session;
}
}
When I let Spring manages the creation of objects, the methods for the
implemented interfaces such as getModel() and prepare() are not invoked. If
I change the class=Menu to class=example.Menu, the interfaces methods
were invoked since I am not letting spring manages object creation.
Could someone let me know what I may have done wrong? How can I use Spring
and Struts at the same time without losing either functionality?
Any help is greatly appreciated.
Thanks!
Lee
ModelDriven, Preparable and SessionAware do not work with Spring
Hi All, I think I know what is the trouble but am still not sure why is this a problem for Struts 2.0. I hope someone from the Struts community can help to shed some light. Or what is the recommended way of aoping the action class if spring proxy is not the route to go. The problem is when I use org.springframework.aop.framework.ProxyFactoryBean to AOP the Action class. Once I remove the AOP piece such as the following, everything work just fine: !--bean id=Menu class= org.springframework.aop.framework.ProxyFactoryBean property name=proxyInterfaces valueexample.IMenu/value /property property name=interceptorNames list valuetimeLoggingAdvisor/value /list /property property name=target ref local=MenuTarget/ /property /bean bean id=MenuTarget class=example.Menu singleton=false/-- bean id=Menu class=example.Menu singleton=false/ Any help is greatly appreciated! Thanks, Lee
Re: caching large data in web application
Well, if the data is read only, then you can just cache the data in a Hashtable and make it accessible through out the application. If your data is volatile, then you may consider writing a simple time based caching service - http://www.javaworld.com/javaworld/jw-07-2001/jw-0720-cache_p.html Hibernate provides two levels of caching. By default, Hibernates uses first level caching. Hibernate also provides plugin for other cache provider like JBoss. This is the second level caching. In first level caching, Hibernate will check if data in a persistence class has changed when saving a persistence class. If the related data is being modified, Hibernate will update the modified data. Of course, this is just one simple example. For more information, please visit Hibernate reference document - http://www.hibernate.org/hib_docs/reference/en/html/ HTH Lee On Mon, 29 Nov 2004 07:36:43 -0800 (PST), Ashish Kulkarni [EMAIL PROTECTED] wrote: Hi The data which i want to cache has about 1 rows and i want to cache it in may be servlet context, what is the best way to cache it, do i just create a java bean and cache it or some kind of mechanism already exist like Hibernation (i am not sure what is does) Ashish --- Frank W. Zammetti [EMAIL PROTECTED] wrote: What kind of data is it? Is it a read-only set of data? How often is it updated? Who or what can update it? There's any number of ways to do things like this, which is the best option depends on the particulars of your use case. You might be able to cache the data in Javascript arrays in the user's browser in a hidden frame. This is a fantastic approach for data that doesn't change frequently and that is read-only. Removes potentially a lot of data being passed in different spots throughout the app, but it does complicate your front-end a little more. You might be able to cache it in the session. This can be good if the data set is small, read-only and needed for server processing at various points. This can lead to problems in distributed environments though, so you need to be careful. You might be able to have a small cache database server running along side your app server, something like MySQL for example, that has temp copies of the data. The benefit to this is you have the full power of the RDBMS to work with, so you might be able to do triggers to update the DB2 database when appropriate if it's a one-way sort of thing. As for the idea of update triggers, sure, you can almost certainly put something together to do this. I haven't done a whole lot with DB2, but I'd bet there's some mechanism you could use to notify your cache server of the update. I'd suspect the best approach would be to notify it a change took place but DON'T send the updated data... Let the cache server do a query to DB2 and get the updated data set. Writing a well-constructed stored procedure to do this would probably be the best bet. You could also just poll DB2 for changes if your application can tolerate some lag in updates to the cached data. Really though, the first question to ask is whether what you want to cache is read-only or has to support updates. If it's the former, you have a lot of options. It it's the later, things get a little trickier. By the way, I think I've done some variation of all these approaches at one time or other, so I can try and expand on things if you need me to. -- Frank W. Zammetti Founder and Chief Software Architect Omnytex Technologies http://www.omnytex.com Dakota Jack wrote: Whatever code updates the database will have to somewhere and somehow notify the code that updates the cache. It is that simple. Jack On Sun, 28 Nov 2004 15:25:56 -0800 (PST), Ashish Kulkarni [EMAIL PROTECTED] wrote: Hi what is the best way to cache data in web application, I have a table in AS400 DB2 database which i want to cache in application server to improve performance, Also is it possible to have a external trigger which will update the cache if the data base is updated by some external process Ashish __ Do you Yahoo!? Meet the all-new My Yahoo! - Try it today! http://my.yahoo.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] __ Do you Yahoo!? The all-new My Yahoo! - What will yours do? http://my.yahoo.com - To unsubscribe, e-mail:
Re: How to retrieve parameters passed via GET method?
In my Struts configuration file, an action element is defined as the following: actionpath=/closeAccount type=org.apache.struts.actions.ForwardAction parameter=/closeAccount.jsp / When customer clicks on the hyperlink, ActionServlet receives the HTTP request, pre-processes it and forwards it to ForwardAction, who will simply forward the request to closeAccount.jsp. That page then asks customer to confirm the operation (are you sure that you want to close account No. 100?). The problem is, ActionServlet seems to have modified the request, so in my closeAccount.jsp, i cannot retrieve the accountId parameter: request.getAttribute(accountId) returns null. I dumped the contents in the HTTP request that closeAccount.jsp receives. They look like this: javax.servlet.forward.request_uri = /badba/closeAccount.do javax.servlet.forward.context_path = /badba javax.servlet.forward.servlet_path = /closeAccount.do javax.servlet.forward.query_string = accountId=100 org.apache.struts.action.mapping.instance = ActionConfig[path=/closeAccount,parameter=/closeAccount.jsp,scope=session,type=org.apache.struts.actions.ForwardAction org.apache.struts.action.MODULE = [EMAIL PROTECTED] Is it possible that the accountId is saved in session scope instead of request scope? You need to specify the scope if you want to save it in request scope: action path=/closeAccount type=org.apache.struts.actions.ForwardAction parameter=/closeAccount.jsp scope=request/ HTH. Lee - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
