JSF Bean Property Initialization - jsf

Question

I have a managed bean called User which has a String property called name:
public class User {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
I have another managed bean called UserManager which has a property of type User and allows you to add a user to a user list:
public class UserManager {
private List<User> userList = new ArrayList<User>();
private User user;
public User getUser() {
return this.user;
}
public void setUser(User user) {
this.user = user;
}
public String addUser() {
userList.add(user);
return "_USERADDED";
}
}
My JSF page to add the user looks like the following:
<h:form>
<h:inputText value="#{userManager.user.name}"/>
<h:commandButton value="Add User" action="#{userManager.addUser}"/>
</h:form>
The problem I am having is when I run my page and click the "Add User" button I get the following error:
adduser.xhtml #11,50 value="#{userManager.user.name}": Target Unreachable, 'null' returned null
I am assuming this error is due to the fact that the user property in UserManager is null and I am trying to access it to set the property name.
I can get this to work if I modify UserManager and initialize the user property:
private User user = new User();
My question is, is this the correct way to initialize the property or can I do it from within the JSF file and/or a config file?

Answer 1

Yes, you're supposed to create it yourself. JSF/EL won't autocreate nested properties. Canonical approach is to use the #PostConstruct for this.
#ManagedBean
#RequestScoped
public class UserManager {
private List<User> userList = new ArrayList<User>();
private User user;
#PostConstruct
public void init() {
user = new User();
}
public String addUser() {
userList.add(user);
return "_USERADDED";
}
public User getUser() {
return user;
}
}
Note that I omitted the setter as it's never used by JSF/EL. I still wonder what userList is doing there, it doesn't belong there. I'll assume that it's just a stub for testing. In that case, it'd probably better be an application or session scoped bean which you inject by #ManagedProperty.