I have an EJB bean injected in a Managed Bean. Its constructor is called twice.
For example, I get:
com.logic.jsf.AdditionManagedBean created
com.logic.Addition$$$view45 created
com.logic.Addition created
I know #PostConstruct but I'm trying to understand why that happens. Is it because of proxy, and in that case shouldn't I see a proxy related literal in the printed name of the class?
#Stateless
#LocalBean
public class Addition{
public Addition(){
System.out.println(this.getClass().getName() +" created");
}
public String getAddition(){
return "Addition";
}
}
Injected in:
#ManagedBean
#RequestScoped
public class AdditionManagedBean {
#EJB
Addition addition;
public AdditionManagedBean(){
System.out.println(this.getClass().getName()+" created");
}
public String getAddition(){
return addition.getAddition();
}
}
Related
I'm trying to inject a bean in a stateless EJB. But i would like that bean be different when EJB is called from a ManagedBean or from a EJB Timer.
Here is my EJB in which i inject a User bean:
MyEjb.java
#Stateless
class MyEjb{
#Inject
#CurrentContext
private User user;
public void foo(){
System.out.println(user);
}
}
Here is a EJB Timer that use the EJB:
TimerTest.java
#Singleton
#Startup
class TimerTest {
#EJB
private MyEjb myEjb;
#Timeout
public void doIt(Timer timer) {
myEjb.foo();
}
#Produces
#CurrentContext
public User produceCurrentUserInEjbTimer(){
return new User("system");
}
}
Finally, the ManagedBean using MyEjb :
MyManagedBean.java
#ManagedBean
#SessionScoped
class MyManagedBean {
#EJB
private MyEjb myEjb;
public void bar() {
myEjb.foo();
}
#Produces
#CurrentContext
#RequestScoped
public User produceCurrentUserInManagedBean(){
return new User(FacesContext.getCurrentInstance().getExternalContext().getRemoteUser());
}
}
When the timeout is reach, i would like that foo method of MyEbj use the system User created by the method produceCurrentUserInEjbTimer.
And when the bar method of the ManagedBean is invoked, i would like that foo method of MyEbj use the remote User of the FaceContext (created by the method produceCurrentUserInManagedBean).
I would rather have only one producer that checks if FacesContext.getCurrentInstance() != null then call the apropriate code:
public User produceCurrentUser(){
if(FacesContext.getCurrentInstance() != null){
return new User(FacesContext.getCurrentInstance().getExternalContext().getRemoteUser());
}
else{
return new User("system");
}
}
You can also inject you User directly on the timer or the ManagedBean and then use InjectionPoint object to know to which class your User is injected:
public User produceCurrentUser(InjectionPoint injectionPoint){
System.out.println(injectionPoint.getBean());
}
You should also use #Named and #javax.enterprise.context.SessionScoped as you have CDI on your application instead of #ManagedBean.
UPDATE
I'm not sure that there is a direct method to get the context of the injection, it wil be possible throw CDI extension but I've never try it.
What about obtaining a contextual instance by programmatic lookup:
#Stateless
class MyEjb{
#Inject #Any Instance<User> userSource;
public void foo(String context) // you should define contexts your self as jms, jsf ...
{
// Every expected context will have a qualifier
Annotation qualifier = context.equals("jsf") ?
new JSFQualifier() : new JMSQualifier();
User p = userSource.select(qualifier).get();
System.out.println(user);
}
}
This was you can inject your EJB and pass the context param to foo:
#Named
#SessionScoped
class MyManagedBean {
#EJB
private MyEjb myEjb;
public void bar() {
myEjb.foo("jsf");
}
}
I have a little javaee webproject and i need bean injection in it. i have a tomee server with cdi enabled. Here is a little test case.
Here is my #SessionScoped User object
import javax.enterprise.context.SessionScoped;
import java.io.Serializable;
#SessionScoped
public class User implements Serializable {
String userName;
public User () {}
public User (String userName) { this.userName = userName; }
public String getUserName() { return userName; }
public void setUserName(String userName) { this.userName = userName; }
}
and here are my two nearly identical beans:
#Named
#RequestScoped
public class BeanOne {
private String message;
#Inject User user;
#PostConstruct
public void init() { user = new User("TestName"); }
public String getMessage() { return user.getUserName(); }
}
In this bean i create a new user. the method getMessage returns the correct user name. I thought the user should still exist in the second bean because its #SessionScoped. Here is my second bean.
#Named
#RequestScoped
public class BeanTwo {
private String message;
#Inject User user;
public String getMessage() { return user.getUserName(); }
}
But in this bean the user.getUserName() returns null. How am i supposed to inject a #SessionScoped bean?
This happens because you have manually initialized user object in BeanOne init method. The purpose of dependency injection is to let some container create instances of objects for you, so you should never initialize objects manually. So just set a name for this user and it will be visible during session for all other beans.
#PostConstruct
public void init() { user.setUserName("TestName"); }
I wanted to know, is there any option to call a managed bean inside of EJB bean. Imagine, we have the code:
#ManagedBean
#SessionScoped
public class MyManagedBean implements Serializable {
public String getUrl() {
return "http://www.google.com";
}
}
#Stateless
public class MyEJB {
#ManagedProperty(value = "#{myManagedBean}")
MyManagedBean myManagedBean;
public void setMyManagedBean(MyManagedBean myManagedBean) {
this.myManagedBean = myManagedBean;
}
public void call() {
// NullPointerException here
System.out.println(myManagedBean.getUrl());
}
}
I also tried this:
#Stateless
public class MyEJB {
#EJB
MyManagedBean myManagedBean;
...
}
... but it returns different MyManagedBean instance.
This is not right. With CDI managed beans instead of JSF managed beans it's possible, but it is just not right as in, bad design. The business service should not be aware about the front-end at all. It makes the business service unreusable on other front-ends than JSF.
You should do it the other way round. You should inject the EJB in the managed bean, not the other way round. The EJB should be kept entirely stateless. You should just directly pass the EJB the information it needs as method argument (and never assign it as instance variable of EJB afterwards).
E.g.
#ManagedBean
#SessionScoped // <-- Did you read https://stackoverflow.com/q/7031885?
public class MyManagedBean implements Serializable {
private String url = "http://www.google.com";
#EJB
private MyEJB myEJB;
public void submit() {
myEJB.call(url);
}
public String getUrl() {
return url;
}
}
and
#Stateless
public class MyEJB {
public void call(String url) {
// No NullPointerException here.
System.out.println(url);
}
}
See also:
JSF Service Layer
I have a JSF web application with a view-scoped bean and a session-scoped bean. I'd like to modify the session bean's members from the view bean, and I followed this guide from a certain well-known JSF guy, but I can't seem to get it to work without a runtime exception. The reference to the managed session bean, "home" is null when referenced, similar to this question except I've already followed the advice of the accepted answer.
package brian.canadaShipping;
import java.io.Serializable;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ManagedProperty;
import javax.faces.bean.ViewScoped;
#ManagedBean(name= "requestBean")
#ViewScoped
public class CpstcRequestBean implements Serializable {
#ManagedProperty(value="#{home}")
private CpstcHomeBean homeBean;
public CpstcHomeBean getHomeBean() {
return homeBean;
}
public void setHomeBean(CpstcHomeBean homeBean) {
this.homeBean = homeBean;
}
private static final long serialVersionUID = -5066913533772933899L;
public String testVar = "hello world";
private boolean displayOutput = false;
public boolean isDisplayOutput() {
return displayOutput;
}
public void setDisplayOutput(boolean displayOutput) {
this.displayOutput = displayOutput;
}
public String getTestVar() {
return testVar;
}
public void setTestVar(String testVar) {
this.testVar = testVar;
}
public CpstcRequestBean()
{
System.out.println("TEST: " + homeBean.toString());
System.out.println("Hello, ResuestBean!");
}
}
The first bit of my "home" bean is as follows:
#ManagedBean(name= "home")
#SessionScoped
public class CpstcHomeBean implements Serializable {
...
UPDATE: I've followed Jordan's suggestions and I have the following in my view-scoped bean:
#ManagedBean(name= "requestBean")
#ViewScoped
public class CpstcRequestBean implements Serializable {
#Inject #Named("home") CpstcHomeBean homeBean;
public CpstcHomeBean getHomeBean() {
return homeBean;
}
public void setHomeBean(CpstcHomeBean homeBean) {
this.homeBean = homeBean;
}
public CpstcRequestBean()
{
System.out.println("TEST: " + homeBean.toString());
System.out.println("Hello, ResuestBean!");
}
...
as well as this in my session-scoped bean:
#Named("home")
#SessionScoped
public class CpstcHomeBean implements Serializable {
...
yet my "home" bean reference is still null. Any ideas?
UPDATE 2: It turns out that you must use #Named in both classes, not just the injected class. My web app now loads but some elements are blank. In my console log, I see, "Target Unreachable, identifier 'home' resolved to null." I'm running on Tomcat 7, if that affects things. Any ideas?
You can either change your session bean's #ManagedBean to #Named and then just inject it into your view scoped bean OR you can reference the session bean as is like this:
FacesContext fc = FacesContext.getCurrentInstance()
private CpstcHomeBean homeBean = (CpstcHomeBean) fc.getApplication().evaluateExpressionGet(fc, "#{home}", CpstcHomeBean.class);
I have a managed bean (SessionScope as follow)
#ManagedBean(name="login")
#SessionScoped
public class Login implements Serializable {
private String userSession;
public Login(){
}
}
In this managedbean, somewhere in the login function, i store the email as a session.
I have another managed bean called ChangePassword (ViewScoped). I need to access the value of the email which is stored in the userSession.
The reason of doing so is that i need to find out the current userSession(email) before i can complete the change password function. (Need change password for that specific email)
How do i do so? New to JSF, appreciate any help!
Just inject the one bean as a managed property of the other bean.
#ManagedBean
#ViewScoped
public class ChangePassword {
#ManagedProperty("#{login}")
private Login login; // +setter (no getter!)
public void submit() {
// ... (the login bean is available here)
}
// ...
}
See also:
Communication in JSF 2.0 - Injecting managed beans in each other
In JSF2, I usually use a method like this:
public static Object getSessionObject(String objName) {
FacesContext ctx = FacesContext.getCurrentInstance();
ExternalContext extCtx = ctx.getExternalContext();
Map<String, Object> sessionMap = extCtx.getSessionMap();
return sessionMap.get(objName);
}
The input parameter is the name of your bean.
if your session scoped bean is like this :
#ManagedBean(name="login")
#SessionScoped
public class Login implements Serializable {
private String userSession;
public Login(){
}
}
you can access the values of this bean like :
#ManagedBean(name="changePassword")
#ViewScoped
public class ChangePassword implements Serializable {
#ManagedProperty(value="#{login.userSession}")
private String userSession;
public ChangePassword (){
}
}
public static Object getSessionObj(String id) {
return FacesContext.getCurrentInstance().getExternalContext().getSessionMap().get(id);
}
public static void setSessionObj(String id,Object obj){
FacesContext.getCurrentInstance().getExternalContext().getSessionMap().put(id, obj);
}
Add them in your managed bean :