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"); }
Related
Still learning JSF and Java and having trouble understanding how to access a session bean property.
I have a LoggedUser session bean which sets the user that is logged in(using the login method).
#ManagedBean(name="loggedUser")
#Stateless
#LocalBean
#SessionScoped
public class LoggedUser {
#EJB
UserEJB userEJB;
#PersistenceContext
private EntityManager em;
private UserEntity loggedUser;
private String loginUserName;
private String loginPassword;
public LoggedUser() {}
public UserEntity getLoggedUser() {
return loggedUser;
}
public void setLoggedUser(UserEntity loggedUser) {
this.loggedUser = loggedUser;
}
public String authenticate() {
if (loggedUser == null) {
return "login.xhtml";
} else {
return "";
}
}
public String login() {
if (userEJB.validateLogin(loginUserName, loginPassword)) {
setLoggedUser(userEJB.fetchUser(loginUserName));
return "index.xhtml";
}
return "";
}
public String getLoginUserName() {
return loginUserName;
}
public void setLoginUserName(String loginUserName) {
this.loginUserName = loginUserName;
}
public String getLoginPassword() {
return loginPassword;
}
public void setLoginPassword(String loginPassword) {
this.loginPassword = loginPassword;
}
}
I want to be able to view the logged user from other areas in the application. I think I am injecting it incorrectly because loggedUser is always null when I am in a different bean for example something like..
#Stateless
#LocalBean
public class HistoryEJB {
#PersistenceContext
EntityManager em;
#ManagedProperty(value = "#{loggedUser}")
private LoggedUser loggedUser;
public LoggedUser getLoggedUser() {
return loggedUser;
}
public void setLoggedUser(LoggedUser loggedUser) {
this.loggedUser = loggedUser;
}
public void testLoggedUser() {
loggedUser.getLoggedUser();
// Just an example but would be null here - why?
}
}
How can I access this property from other areas in my application? Thanks for any help.
You can't use #ManagedProperty in an EJB and you shouldn't inject a view component into a business-tier component, period. #ManagedProperty is strictly web-tier stuff and is able to inject only and into web-tier, JSF components.
Your EJB ought to have a method that accepts a LoggedUser. This way, you can then pass your logged-in user to the EJB (which is the proper flow of data in a web application). What you have now is just turning best practice on its head.
So
Add a provideLoggedUser(LoggedUser loggedUser) method to your EJB
Call that method on your instance of UserEJB from within your managed bean
Rule of Thumb: Your EJB should not be aware of the web application
It seems you are missing the setter and getter for loggedUser. In principe it is there but it is convention to name it as follows
setProperty
and
setProperty
for a field named property. Note the capital first letter of the field name in the setter and getter!
I have this SessionScoped bean:
#ManagedBean
#SessionScoped
public class LoginBean implements Serializable {
/**
* Creates a new instance of LoginBean
*/
public LoginBean() {
this.usuario = new Usuario();
}
private Usuario usuario;
//getter & setter
}
The Usuario class:
public class Usuario {
public Usuario() {
}
private String password;
private String nombre;
private int idPlanta;
private int nivel;
private String idUsuario;
//getters & setters
}
And I want to get the value of the property idPlanta from the SessionScoped bean (LoginBean) here (in the constructor) see the comments:
#ManagedBean
#ViewScoped
public class PrincipalBean implements Serializable {
public PrincipalBean() {
System.out.println(this.login.getUsuario().getIdPlanta());
//AT THIS POINT THE VALUE OF idPlanta IS 0 but in the session I have 1...
//Method that uses the idPlanta value as a parameter
}
#ManagedProperty(value = "#{loginBean}")
private LoginBean login;
public LoginBean getLogin() {
return login;
}
public void setLogin(LoginBean login) {
this.login = login;
}
}
But when I show the value in the view it shows the value that really is in the Session idPlanta = 1. I dont understand why I cant get the value of that property in the constructor of that ViewScoped bean (PrincipalBean). I show the value in the view here(I know I can get it directly fron the LoginBean but this is just to show that the property login in PrincipalBean has the Session value):
<h:outputText class="titulo" value="Bienvenido(a) #{principalBean.login.usuario.nombre} Planta #{principalBean.login.usuario.idPlanta}" />
The value of idPlanta in PrincipalBean is very important because I use it as a method parameter to show more info when the view is showed.
Please help me. I still learning JSF.
You need to be using these values after the bean has been constructed. When your constructor is called, your bean has net yet been initialzed - therefore the injections have not yet happend. Using the #PostConstruct method you will be able to access the desired values from the injected objects.
For example :
#ManagedBean
#ViewScoped
public class PrincipalBean implements Serializable {
public PrincipalBean() {
}
#PostConstruct
public init() {
System.out.println(this.login.getUsuario().getIdPlanta());
//AT THIS POINT THE VALUE OF idPlanta IS 0 but in the session I have 1...
//Method that uses the idPlanta value as a parameter
}
#ManagedProperty(value = "#{loginBean}")
private LoginBean login;
public LoginBean getLogin() {
return login;
}
public void setLogin(LoginBean login) {
this.login = login;
}
}
See Also
Why use #PostConstruct?
Injecting Managed Beans In JSF 2.0
JSF injection with managed property, good pattern?
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 want to use the same object "User" within the Farma and the Pata objects. The object user is first initialized inside the Farma object. I tried to annotated with #inject, but the object user inside Pata, has the name with null value. Please, can anyone help me understand what I am doing wrong? Thank!
#Named
#SessionScoped
public class Farma implements Serializable {
#Inject private User user;
#PostConstruct
public void initialize(){
user.setName("MyName");
}
// Getters and Setters
}
#Named
#SessionScoped
public class Pata implements Serializable {
#Inject private User user;
public String getFuzzyName() {
// Here I want to use the object "user" with the name "MyName" to do some logic
}
// Getters and Setters
}
public class User implements Serializable {
private String name;
// Getters and Setters
Just scoping a User object won't allow you to initialize it.
Use "producer method" to control bean's creation.
Try this:
#SessionScoped
public class Pata implements Serializable {
#Inject
#SessionUser // inject here using the producer method
private User user;
public String getFuzzyName() {
return user.getName();
}
}
#SessionScoped
public class Farma implements Serializable {
#Produces
#SessionUser // qualifier to tie injection points to this method
#SessionScoped // to ensure it will be called once per session for any number of injection points
public User produceUser() {
System.out.println("Creating user");
User u = new User();
u.setName("User");
return u;
}
}
////// that's your custom qualifier, it's in a separate file
#Qualifier
#Retention(RetentionPolicy.RUNTIME)
#Target({METHOD, FIELD, PARAMETER, TYPE})
public #interface SessionUser {}
// no scopes here, it is defined by the producer method
public class User implements Serializable {
private String name;
public void setName(String name) {
this.name = name;
}
public String getName() {
return name;
}
}
You need to understand scoping of CDI beans. The default scope, if none is specified, is the #Dependent scope, which means that an object exists to serve exactly one client (bean) and has the same lifecycle as that client (bean).
In this case it means that the user in Farma only exists for the Farma class and lives for the life of the Farma class.
The user in Pata is a different instance, and its lifecycle matches that of Pata.
You need to properly scope the User object.
As axiopisty said, adding #Named #SessionScoped is the correct way.
I tried and it works great.
#Named
#SessionScoped
public class Pata implements Serializable {
#Inject
private User user;
public String getFuzzyName() {
System.out.println(user.getName());
return user.getName();
}
public User getUser() {
return user;
}
public void setUser(final User user) {
this.user = user;
}
}
#Named
#SessionScoped
public class Farma implements Serializable {
#Inject
private User user;
#PostConstruct
public void initialize() {
user.setName("MyName");
}
// Getters and Setters
public User getUser() {
return user;
}
public void setUser(final User user) {
this.user = user;
}
}
#Named
#SessionScoped
public class User implements Serializable {
private String name = "Default";
public String getName() {
return name;
}
public void setName(final String name) {
this.name = name;
}
}
<h:outputText value="#{farma}"></h:outputText><br />
<h:outputText value="#{pata}"></h:outputText><br />
<h:outputText value="#{pata.fuzzyName}"></h:outputText>
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 :