使用会话中的信息呈现JSF页面

Question

I have the following JSF page:

<h:head>
    <title>Admin Page</title>        
</h:head>
<h:body>

    <h1>Users List</h1>

    <h:dataTable value="#{adminBean.linkArr}" var="o" >

        <h:column>
            <f:facet name="header">User name</f:facet>
            #{o.username}
        </h:column>

    </h:dataTable>        

</h:body>

And a managed bean like this:

@ManagedBean(name="adminBean")
@SessionScoped
public class AdminBean {

private static UserLink[] linkArr;

public AdminBean() {
    FacesContext context = FacesContext.getCurrentInstance();  
    HttpServletRequest request = (HttpServletRequest)context.getExternalContext().getRequest();  
    HttpSession session = request.getSession();

    String values[] = (String[])request.getSession().getAttribute("userList");

    int userNos = values.length;
    linkArr = new UserLink[userNos];

    for(int i = 0; i < userNos; ++i) {
        String tmp = values[i];
        linkArr[i] = new UserLink(tmp);
    }                
}
public UserLink[] getLinkArr() {
    return linkArr;
}

public static class UserLink {

    public String username;

    public UserLink(String username) {
        this.username = username;
    }

    public String getUsername() {
        return username;
    }
}
}

What I am actually trying to do is:

Save some data from a previously called servlet by creating a session. Assuming that a managed session bean is only created when its associated XHTML file is called, I am getting the attributes from the session object and using then to populate a JSF table.

However, instead of a JSF table, I am getting the following output:

Users List

User name #{o.username}

Am I assuming a wrong lifecycle for a managed session bean or there is some problem in my JSF page?

Answer 1

So, EL isn't evaluated at all? That can only mean that the current request URL (as you see in browser's address bar) didn't match the <url-pattern> of the FacesServlet as configured in webapp's web.xml . It's namely the one responsible for parsing the XHTML file into a JSF component tree and letting it to evaluate all EL expressions and generate valid HTML code. If you have done rightclick, View Source in the webbrowser, you should also have noticed that: all JSF tags are left unparsed instead of that their HTML representation is been generated.

So, to fix this problem, you need to make sure that the current request URL matches the URL pattern of the faces servlet. So, if you have mapped it on *.jsf , then you should open the page by page.jsf instead of by page.xhtml . Alternatively, you can also just change the URL pattern of the faces servlet in web.xml to be *.xhtml , so that you never need to worry about virtual URLs.

Please note that this problem is unrelated to the session management. You might perhaps run into problems related to that sooner or later given the strange design, but that's thus a different problem.

See also:

• JSF Facelets: Sometimes I see the URL is .jsf and sometimes .xhtml. Why?