CODEWITHSUNDEEP
jsf
Mitch Talmadge
Mitch Talmadge

Reputation: 4755

Dynamic Directory in Java EE Web Application

I have created a Java EE application that uses JSF. In my web directory, I have a file named index.xhtml. My goal is to serve different content on this webpage based upon the parent directory's name.

For example:

http://localhost:8080/myapp/1/index.xhtml would print You accessed through "1". http://localhost:8080/myapp/1234/index.xhtml would print You accessed through "1234".

I do not want to create a directory for every single possible number; it should be completely dynamic.

Additionally, I need my navigation rules to still be usable. So if I have a navigation rule such as this:

<navigation-rule>
    <display-name>*</display-name>
    <from-view-id>*</from-view-id>
    <navigation-case>
        <from-outcome>index</from-outcome>
        <to-view-id>/index.xhtml</to-view-id>
        <redirect />
    </navigation-case>
</navigation-rule>

Then if I am in the directory 1234, it will still redirect to the index.xhtml page within 1234.

Is this possible? How can I do this?

Upvotes: 4

Views: 558

Answers (1)

BalusC
BalusC

Reputation: 1108632

In order to forward /[number]/index.xhtml to /index.xhtml whereby [number] is been stored as a request attribute, you need a servlet filter. The doFilter() implementation can look like this:

@WebFilter("/*")
public class YourFilter implements Filter {

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) req;
        String[] paths = request.getRequestURI().substring(request.getContextPath().length()).split("/");

        if (paths.length == 3 && paths[2].equals("index.xhtml") && paths[1].matches("[0-9]{1,9}")) {
            request.setAttribute("directory", Integer.valueOf(paths[1]));
            request.getRequestDispatcher("/index.xhtml").forward(req, res);
        }
        else {
            chain.doFilter(req, res);
        }
    }

    // ...
}

It makes sure the number matches 1 to 9 latin digits and stores it as a request attribute identified by directory and finally forwards to /index.xhtml in context root. If nothing maches, it simply continues the request as if nothing special happened.

In the /index.xhtml you can access the number by #{directory}.

<p>You accessed through "#{directory}"</p>

Then, in order to make sure JSF navigation (and <h:form>!) keeps working, you need a custom view handler which overrides the getActionURL() to prepend the URL with the path represented by directory request attribute, if any. Here's a kickoff example:

public class YourViewHandler extends ViewHandlerWrapper {

    private ViewHandler wrapped;

    public YourViewHandler(ViewHandler wrapped) {
        this.wrapped = wrapped;
    }

    @Override
    public String getActionURL(FacesContext context, String viewId) {
        String actionURL = super.getActionURL(context, viewId);

        if (actionURL.endsWith("/index.xhtml")) {
            Integer directory = (Integer) context.getExternalContext().getRequestMap().get("directory");

            if (directory != null) {
                actionURL = actionURL.substring(0, actionURL.length() - 11) + directory + "/index.xhtml";
            }
        }

        return actionURL;
    }

    @Override
    public ViewHandler getWrapped() {
        return wrapped;
    }

}

In order to get it to run, register in faces-config.xml as below.

<application>
    <view-handler>com.example.YourViewHandler</view-handler>
</application>

This is also pretty much how JSF targeted URL rewrite engines such as PrettyFaces work.

See also:

Upvotes: 4

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