Interception with CDI works perfectly in #Named , but doesn't in #ManagedBean:
Logable.java
#InterceptorBinding
#Retention(RUNTIME)
#Target({TYPE, METHOD})
public #interface Logable {
}
LoggingInterceptor.java
#Logable
#Interceptor
public class LoggingInterceptor {
#AroundInvoke
public Object log(InvocationContext ctx) throws Exception {
//log smth. with ctx.
}
}
WorkingBean.java
#Named
#Logable
public class WorkingBean implements Serializable {
//works : methods will be logged
}
beans.xml
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<beans xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/beans_1_0.xsd">
<interceptors>
<class>LoggingInterceptor</class>
</interceptors>
</beans>
ViewScopedBean.java
#Logable
#ManagedBean
public class ViewScopedBean implements Serializable {
//doesn't work
}
I'm aware, that this kind of Interceptor is meant to work with WebBeans (and EJB),
but i'm searching for solution for both worlds (described + JSF) with same Interceptor concept
I need #ViewScoped #ManagedBean, thats why i cant get rid of #ManagedBean in favour of pure WebBeans
System:
Mojarra 2.1.7
Primefaces 3.2
As far as I understand, there isn't one. JSF doesn't have anything supporting interception.
JSF does not support the CDI interception like you have posted per se. A CDI interceptor will work for lifecycle methods like #PostConstruct
#Inherited
#InterceptorBinding
#Retention(RUNTIME)
#Target({TYPE})
public #interface TypeLogger {
#Nonbinding
public LoggingLevel logLevel() default LoggingLevel.INFO;
}
Here is how it would be used since it only binds to the #Target({TYPE})
#ManagedBean
#ViewScoped
#TypeLogger
public class Index implements Serializable {
private static final long serialVersionUID = 3336392241545517919L;
#PostConstruct
private void init() {
setup();
}
}
Related
I'm currently evaluating Java EE 6 / JSF 2.1 with RichFaces.
A bean which is declared as
#ManagedBean
#ViewScoped
Gets an ID set (to prepare e.g. a delete operation).
Via JSF a confirmation popup is displayed.
If the user confirms, the delete method is invoked and removes the row for which the ID was stored in step 1.
Since CDI beans don't have a ViewScope I tried to declare the bean as:
#Named
#ConversationScoped
Now the processing fails in step 3. because the value that was set in step 1 (checked that) is no longer available.
Do I have to use Conversation.begin() and Conversation.end() methods?
If so, where would be good place to invoke them?
If you can upgrade to JSF 2.2, immediately do it. It offers a native #ViewScoped annotation for CDI.
import javax.faces.view.ViewScoped;
import javax.inject.Named;
#Named
#ViewScoped
public class Bean implements Serializable {
// ...
}
Alternatively, install OmniFaces which brings its own CDI compatible #ViewScoped, including a working #PreDestroy (which is broken on JSF #ViewScoped).
import javax.inject.Named;
import org.omnifaces.cdi.ViewScoped;
#Named
#ViewScoped
public class Bean implements Serializable {
// ...
}
Another alternative is to install MyFaces CODI which transparently bridges JSF 2.0/2.1 #ViewScoped to CDI. This only adds an autogenerated request parameter to the URL (like #ConversationScoped would do).
import javax.faces.bean.ViewScoped;
import javax.inject.Named;
#Named
#ViewScoped
public class Bean implements Serializable {
// ...
}
If you really need to use #ConversationScoped, then you indeed need to manually begin and end it. You need to #Inject a Conversation and invoke begin() in the #PostConstruct and end() in the latest step of the conversation, usually an action method which redirects to a new view.
import javax.enterprise.context.Conversation;
import javax.enterprise.context.ConversationScoped;
import javax.inject.Named;
#Named
#ConversationScoped
public class Bean implements Serializable {
#Inject
private Conversation conversation;
// ...
#PostConstruct
public void init() {
conversation.begin();
}
public String submit() {
// ...
conversation.end();
return "some.xhtml?faces-redirect=true";
}
}
See also:
How to choose the right bean scope?
I think you can benefit from CDI extension to create your own scope so you can implement the context and use the #NormalScope.
CDI fires an event AfterBeanDiscovery after each bean call
You can use CDI extension to #Observes this event and add your context implementation
In your scope implementation you can :
Use Contextual to get your bean by its name from FacesContext ViewRoot Map and return it after each ajax call back
Use CreationalContext if the bean name from first step is not found to create it in the FacesContext ViewRoot Map
For a more in-depth explanation, I recommend this link : http://www.verborgh.be/articles/2010/01/06/porting-the-viewscoped-jsf-annotation-to-cdi/
Inject the conversation into your bean and in the #PostConstructor method start the conversation if the conversation is transient.
And after deleting the record, end your conversation and navigate to your destination page. When beginning a conversation. Here is an example
public class BaseWebBean implements Serializable {
private final static Logger logger = LoggerFactory.getLogger(BaseWebBean.class);
#Inject
protected Conversation conversation;
#PostConstruct
protected void initBean(){
}
public void continueOrInitConversation() {
if (conversation.isTransient()) {
conversation.begin();
logger.trace("conversation with id {} has started by {}.", conversation.getId(), getClass().getName());
}
}
public void endConversationIfContinuing() {
if (!conversation.isTransient()) {
logger.trace("conversation with id {} has ended by {}.", conversation.getId(), getClass().getName());
conversation.end();
}
}
}
#ConversationScoped
#Named
public class yourBean extends BaseWebBean implements Serializable {
#PostConstruct
public void initBean() {
super.initBean();
continueOrInitConversation();
}
public String deleteRow(Row row)
{
/*delete your row here*/
endConversationIfContinuing();
return "yourDestinationPageAfter removal";
}
}
There is a project which holds an extentions to the Java EE stack features: DeltaSpike. It is a consolidation of Seam 3, Apache CODI. Above others, it includes the #ViewScoped into CDI. This is an old article and by now it has reached version 1.3.0
You can use:
import javax.annotation.PostConstruct;
import javax.faces.view.ViewScoped;
import javax.inject.Named;
#Named
#ViewScoped
public class PageController implements Serializable {
private String value;
public void setValue(String value) {
this.value = value;
}
public String getValue() {
return value;
}
public void execute() {
setValue("value");
}
#PostConstruct
public void init() {
System.out.println("postcontructor");
}
}
Every time I try to inject a session-scoped bean into my view-scoped beans, I get a NullPointerException when calling said bean. This problem is directly related to auto -instantiate a session bean?
Here is what I tried so far:
faces-config.xml
<managed-bean>
<managed-bean-name>sessionBean</managed-bean-name>
<managed-bean-class>com.example.SessionBean</managed-bean-class>
<managed-bean-scope>session</managed-bean-scope>
</managed-bean>
<managed-bean>
<managed-bean-name>viewBean</managed-bean-name>
<managed-bean-class>com.example.ViewBean</managed-bean-class>
<managed-bean-scope>view</managed-bean-scope>
<managed-property>
<property-name>sessionBean</property-name>
<property-class>com.example.SessionBean</property-class>
<value>#{sessionMBean}</value>
</managed-property>
</managed-bean>
SessionBean.java:
package com.example;
public class SessionBean {
public SessionBean() {
System.out.println("Session is instantiated.");
}
public void sayHello() {
System.out.println("Hello from session");
}
}
ViewBean.java:
package com.example;
public class ViewBean {
private SessionBean sessionBean;
private String text = "Look at me!";
public ViewBean() {
System.out.println("View bean is instantiated.");
sessionBean.sayHello();
}
public SessionBean getSessionBean() {
return sessionBean;
}
public void setSessionBean(SessionBean sessionBean) {
this.sessionBean = sessionBean;
}
public String getText() {
return text;
}
}
and the relevant content of index.xhtml:
<f:view>
<h:outputText value="#{viewBean.text}"/>
</f:view>
And this is what I get:
com.sun.faces.mgbean.ManagedBeanCreationException: Cant instantiate class: com.example.ViewBean.
...
Caused by: java.lang.NullPointerException
at com.example.ViewBean.(ViewBean.java:12)
This runs (or rather doesn't run) on weblogic-10.3.6 with the shipped jsf-2-0.war deployed as a library.
What am I doing wrong here? I'm hoping this is not a container bug...
You cannot access the #SessionScoped bean in the #ViewScoped constructor. The #SessionScoped bean will be set AFTER the constructor of the #ViewScoped bean has been called.
Use the #PostConstruct annotation in some kind of init method to access the #SessionScoped bean.
public ViewBean() {
System.out.println("Constructor viewbean");
}
#PostConstruct
public void init() {
sessionBean.sayHello();
}
Further Links:
Why use #PostConstruct?
Spring Injection - access to the injected object within a constructor
I created an ejb
#Stateless
#LocalBean
public class BasitBean {
public String helloBasit() {
return "Basit";
} //end of helloBasit()
} //end of class BasitBean
I am calling it from JSF like
<h:body>
<h:outputLabel value="#{helloBasit.callBasit()}" />
</h:body>
#ManagedBean
#SessionScoped
public class HelloBasit {
#EJB
private BasitBean basitBean;
/** Creates a new instance of HelloBasit */
public HelloBasit() {
}
public String callBasit() {
return basitBean.helloBasit();
} //end of callBasit()
} //end of class HelloBasit
This code is working fine. But when i change the code like this
<h:body>
<h:outputLabel value="#{helloBasit.label}" />
</h:body>
#ManagedBean
#SessionScoped
public class HelloBasit {
#EJB
private BasitBean basitBean;
String label;
/** Creates a new instance of HelloBasit */
public HelloBasit() {
System.out.println();
String label = basitBean.helloBasit();
System.out.println(label);
}
public BasitBean getBasitBean() {
return basitBean;
}
public void setBasitBean(BasitBean basitBean) {
this.basitBean = basitBean;
}
public String getLabel() {
return label;
}
public void setLabel(String label) {
this.label = label;
}
} //end of class HelloBasit
Then i get the exception
SEVERE: Error Rendering View[/index.xhtml]
com.sun.faces.mgbean.ManagedBeanCreationException: Cant instantiate class: pk.mazars.basitMahmood.HelloBasit.
at com.sun.faces.mgbean.BeanBuilder.newBeanInstance(BeanBuilder.java:193)
at com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:102)
......
Why i am getting this exception? The flow should be what i understand is when my page encounters #{helloBasit.label} then my constructor get call, instance variable get initialized, injected the bean instance into the basitBean, then the bean method should call. But i am getting null in the bean instance in this case why? Why previous code is working and it is not ? How can i call bean from the constructor ?
Thank you.
try to move your content of the constructor into a post constructor instead...
like this
#PostConstruct
private void init() {
System.out.println();
String label = basitBean.helloBasit();
System.out.println(label);
}
Cause the ejb bean should be injected only after the managed bean has been initiated
The #PostConstruct is being run after the constructor (after that the managed bean itself was created by the JSF) and only then the EJB is being injected into the bean and can be accessed...
Your idea is correct, but I see some things that may be fixed.
#LocalBean annotation is not required if your EJB is not directly implementing an interface. In this case, with or without the #LocalBean annotation you have the same effect. You may leave that if you want to make it explicit though. See this.
Make sure both #ManagedBean and #SessionScoped import from javax.faces.bean package.
Please, see this working sample:
EJB
import javax.ejb.Stateless;
#Stateless
public class PersonService {
public String getName() {
return "Cloud Strife";
}
}
Managed Bean
import javax.annotation.PostConstruct;
import javax.ejb.EJB;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
#ManagedBean
#SessionScoped
public class PersonBean {
#EJB
private PersonService ps;
private String name;
#PostConstruct
public void init() {
name = ps.getName();
}
public String getName() {
return name;
}
}
XHTML Page
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html">
<f:view contentType="text/html">
<h:head>
<title>Test</title>
</h:head>
<h:body>
<h1>Welcome, #{personBean.name}</h1>
</h:body>
</f:view>
</html>
If your value should be loaded only once, say at your bean construction, always prefer a method with #PostConstruct annotation instead of the constructor.
Also, in order to call bean methods before rendering a view you could use a f:event tag, for example:
<f:event type="preRenderView" listener="#{personBean.init}" />
I hope it helps!
I have read the following post which was very helpful
Migrating from JSF 1.2 to JSF 2.0
but I am having a problem with the migration as I have a custom view handler which extends from FaceletViewHandler - this is not part of faclets 2.
I am migrating on JBoss 4.2.2 the following:
- JSF 1.2 to JSF 2.0
I also want to migrate the faclets - which i have a problem described above.
In my application, I am also using Tomahawk - is there any problem with this migration?
Thanks in advance.
Elico.
Right, you need to replace FaceletViewHandler by ViewHandlerWrapper.
So the following basic FaceletViewHandler implementation:
import javax.faces.application.ViewHandler;
import com.sun.facelets.FaceletViewHandler;
public class MyViewHandler extends FaceletViewHandler {
public MyViewHandler(ViewHandler parent) {
super(parent);
}
// ...
}
needs to be updated as follows:
import javax.faces.application.ViewHandler;
import javax.faces.application.ViewHandlerWrapper;
public class MyViewHandler extends ViewHandlerWrapper {
private ViewHandler wrapped;
public MyViewHandler(ViewHandler wrapped) {
this.wrapped = wrapped;
}
#Override
public ViewHandler getWrapped() {
return wrapped;
}
// ...
}
I've updated my answer on the migration question accordingly.
To activate MyViewHandler e.g. for JEE7, WEB-INF/faces-config.xml should be defined like:
<?xml version="1.0"?>
<faces-config version="2.2" xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
http://xmlns.jcp.org/xml/ns/javaee/web-facesconfig_2_2.xsd">
<application>
<view-handler>pkg.MyViewHandler</view-handler>
</application>
</faces-config>
The first "nonpostback" request to viewBean, someValue property in sessionBean is null.
Now, in a postback request, I am setting a user input to someValue. The problem is that someValue is always null in any "nonpostback" request.
Here is my code:
#ManagedBean
#ViewScoped
public class ViewBean implements Serializable {
#ManagedProperty(value = "#{sessionBean}")
private SessionBean sessionBean;
private String inputText;
#PostConstruct
public void init() {
if (sessionBean.getSomeValue() != null) // ALWAYS NULL
doSomething(sessionBean.getSomeValue());
}
private void doSomething(String s) {}
public void action(final ActionEvent ae) {
sessionBean.setSomeValue(getInputText());
doSomething(getInputText());
}
GETTERS/SETTERS
}
#ManagedBean
#SessionScoped
public class SessionBean implements Serializable {
private String someValue;
GETTER/SETTER
}
I feel I am doing something wrong. I am using Mojarra 2.1.2
Any advice is appreciated. Thank you.
UPDATE:
Using evaluateExpressionGet on both methods (init and action) works fine:
FacesContext context = FacesContext.getCurrentInstance();
SessionBean sessionBean = context.getApplication().evaluateExpressionGet(context,
"#{sessionBean}", SessionBean.class);
This is a known issue:
SessionScoped bean inside a ViewScoped bean is resolved as different bean depending on the expression used
I just changed the state saving method in my web.xml:
<context-param>
<param-name>javax.faces.STATE_SAVING_METHOD</param-name>
<param-value>server</param-value>
</context-param>
I use GAE (Google App Engine) and need to set javax.faces.STATE_SAVING_METHOD to client. This problem can have workaround. After the action, just call refreshSession() with new value force the session object persist
protected void refreshSession(){
saveSession(CeaConst.SESSION_ATTR_NAME_LAST_REFRESH_TIME, new java.util.Date());
}