(Java EE 6 with Glassfish 3.1)
I have a property file that I want to process only once at start up time, so I did this
public class Config implements ServletContextListener{
private static final String CONFIG_FILE_PATH = "C:\\dev\\harry\\core.cfg";
private static final String CONFIG_ATTRIBUTE_NAME = "config";
private long startupTime;
private ConfigRecord config;
#Override
public void contextInitialized(ServletContextEvent sce) {
this.startupTime = System.currentTimeMillis() / 1000;
this.config = new ConfigRecord(CONFIG_FILE_PATH); //Parse the property file
sce.getServletContext().setAttribute(CONFIG_ATTRIBUTE_NAME, this);
}
#Override
public void contextDestroyed(ServletContextEvent sce) {
//Nothing to do here
}
public ConfigRecord getConfig() {
return config;
}
public long getStartupTime() {
return startupTime;
}
}
and in web.xml, i register it as follow
<listener>
<listener-class>com.wf.docsys.core.servlet.Config</listener-class>
</listener>
Now how do I access the ConfigRecord config from the managed bean. I try this
#ManagedBean
#RequestScoped
public class DisplayInbound {
#EJB
private CoreMainEJBLocal coreMainEJBLocal;
#javax.ws.rs.core.Context
private ServletContext servletContext;
public void test(){
Config config = (Config) servletContext.getAttribute("config")
ConfigRecord configRecord = config.getConfig();
}
}
I dont think it work. Got NullPointerException.
That #Context annotation is only applicable in a JAX-RS controller, not in a JSF managed bean. You have to use #ManagedProperty instead. The ServletContext is available by ExternalContext#getContext(). The FacesContext itself is available by #{facesContext}.
#ManagedProperty(value="#{facesContext.externalContext.context}")
private ServletContext context;
Or because you stored the listener as a servletcontext attribute, which is basically the same as the JSF application scope, you could also just set it as managed property by its attribute name:
#ManagedProperty(value="#{config}")
private Config config;
But since you're on JSF 2.0, I'd suggest to use an #ApplicationScoped #ManagedBean instead which is eagerly constructed. With #PostConstruct and #PreDestroy in such a bean you have similar hooks on webapp's startup and shutdown as in a ServletContextListener.
#ManagedBean(eager=true)
#ApplicationScoped
public void Config {
#PostConstruct
public void applicationInitialized() {
// ...
}
#PreDestroy
public void applicationDestroyed() {
// ...
}
}
You can inject it in another beans the usual #ManagedProperty way and access it in the views the usual EL way.
Related
Thanks to this post, https://stackoverflow.com/a/28047512/1227941 I am now using CDI to make msg available in my #Named beans like this:
#RequestScoped
public class BundleProducer {
#Produces
public PropertyResourceBundle getBundle() {
FacesContext context = FacesContext.getCurrentInstance();
return context.getApplication().evaluateExpressionGet(context, "#{msg}", PropertyResourceBundle.class);
}
}
With Injection like:
#Inject
private PropertyResourceBundle bundle;
The question: What should I do if I have more property files: ui.properties, admin.properties ...?
I'd simply use a classifier annotation to choose which bundle to inject. Ripped from a little project of mine:
The annotation:
#Qualifier
#Target({ ElementType.TYPE, ElementType.METHOD, ElementType.FIELD, ElementType.PARAMETER })
#Retention(RetentionPolicy.RUNTIME)
public #interface Bundle {
#Nonbinding
public String value() default "";
}
The producer method (adapt as necessary for your context):
#Produces #Bundle ResourceBundle loadBundle(InjectionPoint ip) {
String bundleName = ip.getAnnotated().getAnnotation(Bundle.class).value();
ResourceBundle res = ResourceBundle.getBundle(bundleName);
return res;
}
And the injection:
#Inject #Bundle("ui")
private ResourceBundle uiResources;
I try to achieve resource injection for a long time but couldn't succeeded.
I use JSF 2.2, JDK 1.7. And my ide is eclipse luna.
I have a session scoped bean called UserBean and view scoped bean called SettingsBean.
I set them in faces-config.xml UserBean as session scoped and SettingsBean as view scoped with their bean name "settingsBean" and "userBean"
public class SettingsBean implements Serializable {
private static final long serialVersionUID = 1L;
#Inject // I also tried #ManagedProperty but didn't work
private UserBean userBean;
#PostConstruct
public void init(){
System.out.println(userBean.getUser().getFullName());
}
public UserBean getUserBean() {
return userBean;
}
public void setUserBean(UserBean userBean) {
this.userBean = userBean;
}
}
The problem is I get userBean as null. What is the problem here?
Thanks for help.
I removed ManagedBean and ViewScoped definitions in faces-config.xml for settingsBean and added them in SettingsBean.java file manually.
And added this also:
#ManagedProperty(value="#{userBean}")
private UserBean userBean;
So finally, it works:
#ManagedBean
#ViewScoped
public class SettingsBean implements Serializable{
private static final long serialVersionUID = 1L;
#ManagedProperty(value="#{userBean}")
private UserBean userBean;
//...
#PostConstruct
public void init(){
System.out.println(userBean.getUser().getFullName());
}
public UserBean getUserBean() {
return userBean;
}
public void setUserBean(UserBean userBean) {
this.userBean = userBean;
}
}
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 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 want a managed bean to run internally on start up in my JSF web application when the application loads. How can I write this class and configure in Glassfish?
In JSF with CDI, observe the initialization of the application scope.
#Named
#ApplicationScoped
public class App {
public void startup(#Observes #Initialized(ApplicationScoped.class) Object context) {
// ...
}
public void shutdown(#Observes #Destroyed(ApplicationScoped.class) Object context) {
// ...
}
}
When having OmniFaces at hands, this can be simplified with #Eager.
#Named
#Eager
#ApplicationScoped
public class App {
#PostConstruct
public void startup() {
// ...
}
#PreDestroy
public void shutdown() {
// ...
}
}
In JSF 2.2- with the now deprecated javax.faces.bean annotations, use an application scoped managed bean which is eagerly initialized.
#ManagedBean(eager=true)
#ApplicationScoped
public class App {
#PostConstruct
public void startup() {
// ...
}
#PreDestroy
public void shutdown() {
// ...
}
}