Thursday May 10, 2007

Howto win a Helicopter

How to win a helicopter @ JavaONE

BT had a booth at JavaONE for their Web21C SDK.  The SDK, among other things, allows you to write software that invokes a WebService hosted by BT to place a phone call between 2 parties.  You simply need to provide 2 phone numbers and BT calls both parties and connects the two.  They provide a limited amount of usage for free, and for a small fee you can use their service more, here's a link to their pricing.  The Web21C SDK opens up the door to many possibilities, however, that's outside the scope of this blog.

BT was offering a challenge at their booth: Use their SDK to place a phone call and win a remote controlled helicopter.  My son is 5 and would love to crash the helicopter, and it sounded like any easy task for GlassFish + JSFTemplating... so I got to work!

Here's what I had to do:

1) I started with the JSFTemplating demo application. (Note: I used the version from CVS so that I would already have a build environment setup which uses APT.)

2) I added the Web21C jar files to my WEB-INF/lib directory of the demo app.  They gave me a memory stick with these, but I think you can find them here.

3) I had problems w/ some of their jar files because many of them are already part of GlassFish and were not needed.  Also some of the versions may not have been compatible.  I ended up turning off classloader delegation by adding this to my sun-web.xml file:

  <class-loader delegate="false"/>

4) I registered my application.  BT requires you to register your application.  This was a necessary, but the most painful part of the process.  It required me to download the Web21C-Certificate-Tool, patch the JDK with the unlimited strength policy files, run their certificate tool, place the generated file in the WEB-INF/classes directory of the demo app, and create / place a file in the WEB-INF/classes directory that pointed to the generated file.

5) With the environment finally setup, I was ready to write the app!  I created the following JSFTemplating page:


<sun:head />
<sun:messageGroup />
<sun:propertySheetSection label="Web21 Phone Dialer">
<sun:textField required="true" label="Call From:" value="#{requestScope.from}" />
<sun:textField required="true" label="Call To:" value="#{}" />
<sun:button text="Make Call">
<!command"#{requestScope.from}", to="#{}");

6) I created the following handler in a new java file called (see above call.jsf page where the button is invoking this handler):

package org.example.handlers;

import com.sun.jsftemplating.annotation.Handler;
import com.sun.jsftemplating.annotation.HandlerInput;
import com.sun.jsftemplating.annotation.HandlerOutput;
import com.sun.jsftemplating.layout.descriptors.handler.HandlerContext;

\* <p> This class is written to demonstrate how to write a
\* <code>Handler</code>.</p>
public class Web21CHandlers {

\* <p> This is a handler makes phone calls.</p>
\* @param context The <code>HandlerContext</code>.
@HandlerInput(name="to", type=String.class, required=true),
@HandlerInput(name="from", type=String.class, required=true)
public static void calculateResponse(HandlerContext context) {
// Get the input.
String to = (String) context.getInputValue("to");
if (!to.startsWith("tel:+")) {
to = "tel:+" + to;
String from = (String) context.getInputValue("from");
if (!from.startsWith("tel:+")) {
from = "tel:+" + from;
} tpc = new, from);

7) I compiled the app (just typed "ant" on the command line, the demo application already has the build environment setup), started the server and went to http://localhost:8080/demo/call.jsf where I saw:


After typing in the 2 phone numbers and clicking the "Make Call" button... the 2 phones rang! 

8) Finally... I showed this to the Web21C people and they gave me a helicopter!

Ken and Senthil 

(I'm in the blue Sun shirt.  You can also see this on flickr.)

That's how to get a helicopter using JSFTemplating + Web21C + GlassFish at JavaONE.

Sunday May 06, 2007

Streaming Content in JSF with JSFTemplating's FileStreamer



I have received questions from several people about how to use the "FileStreamer" feature of JSFTemplating.  So I thought a blog would be the best way to demonstrate how it works. 

FileStreamer provides the ability for the FacesServlet to stream content to the client (i.e. web browser).  If that sounds generic, it is because FileStreamer is very generic.  It allows you to define a ContentSource that is capable of getting content from just about anywhere.  You might choose to get content from a database, retrieve it via a web service, generate it in code, access it from the filesystem or the classpath, or just about anywhere else.  The ContentSource interface allows you to specify the content and information about it so that appropriate http headers will be set, causing the client (browser) to treat it correctly (i.e. Content-type, Content-Disposition, etc.).  In addition to this, FileStreamer works in the context of JSF, meaning you will have access to managed beans or anything you require from your JSF environment.  (NOTE: FileStreamer actually provides a Context which interacts with its environment.  This allows different Context implementations to be provided for different environments; Servlet and JSF Contexts are currently available, see: ServletStreamerContext and FacesStreamerContext).

Lets look at a couple of examples.


First you have to have your JSFTemplating evironment setup.  Follow these instructions for this. 

Next to configure FileStreamer for JSF, add the following to your web.xml file:


The context-param registers 2 ContentSources.  The source to both of these is checked into JSFTemplating's demo application.  You can browse that source online here.  The servlet-mapping requires a prefix mapping and needs its own dedicated FacesServlet mapping.  "/resource/\*" is the default, however, this can be configured, see RESOURCE_PREFIX for more info.


Let's take a look at the key part of the ExampleContentSource to see how it works.

public InputStream getInputStream(Context ctx) throws IOException {
// See if we already have it.
InputStream in = (InputStream) ctx.getAttribute("inputStream");
if (in == null) {
// Create some content...
in = new ByteArrayInputStream(("<b>Hello! You requested: '"
+ ctx.getAttribute(Context.FILE_PATH) + "'</b>").getBytes());

// Set the extension so it can be mapped to a MIME type
ctx.setAttribute(Context.CONTENT_TYPE, "text/plain");

// Save in case method is called multiple times
ctx.setAttribute("inputStream", in);

// Return the InputStream
return in;

The above ContentSource (ExampleContentSource) is very simple, it generates its content from a String (see green text above).  The String is some text with the request path (which is the PATH_INFO of the request, in other words the part of the URL after the "/resource").  Notice I added some HTML tags to show how they're treated.  The red text shows that the Content-type is being explicitly set to "text/plain".  This should cause the browser not to parse any html (so we should see those <b> tags on the screen).

 ExampleContentSource in action

As you can see, this simple ContentSource produces plain text in the browser.  You also see that the URL requires "contentSourceId=example".  "example" comes from the "id" of ExampleContentSource.


Let's take a look at 1 more example ContentSource.  We'll use the same URL, except we'll use the contentSourceId of "proxy" to target our other ContentSource.  Below is the interesting part of the source code for

public InputStream getInputStream(Context ctx) throws IOException {
// See if we already have it.
InputStream in = (InputStream) ctx.getAttribute("inputStream");
if (in == null) {
// Get the path...
String path = (String) ctx.getAttribute(Context.FILE_PATH);
while (path.startsWith("/")) {
path = path.substring(1);

// Get the URL...
URL url = new URL("http://" + path);

// Set the extension so it can be mapped to a MIME type
int index = path.lastIndexOf('.');
if (index > 0) {
ctx.setAttribute(Context.EXTENSION, path.substring(index + 1));

// Open the InputStream
in = url.openStream();

// Save in case method is called multiple times
ctx.setAttribute("inputStream", in);

// Return the InputStream
return in;

Again we are creating an InputStream, however, this time we are getting it via a URL.  This time instead of hard-coding the Content-type, we're setting the extension of the file so that it will be mapped to an appropriate Content-type.  Here's the output for the same URL as before (except w/ our "proxy" contentSourceId):

ProxyContentSource in action!

In this example, the content is pulled from from the server (not the client), then streamed to the client.  The appropriate Content-type of "image/gif" was sent to the browser so that it could treat the content correctly.  If you run this example, try other urls and types of media (html, pdf, doc, etc.).

I hope this blog gives you an idea of how FileStreamer functionality is useful.  Please leave a comment and let me know what you think!  Below is one more section describing how to configure FileStreamer in a Servlet environment (doesn't need JSF):

Servlet Setup



That's it... the rest is the same as above.  You can change the url mapping directly in the web.xml file in this case.  Oh... and yes, you can use the same ContentSources in both environments!

Have Fun!


Thursday Feb 15, 2007

Woodstock is here!


Woodstock JavaServer Faces Components 

Sun has delivered some great components as part of Sun Java Studio Creator and NetBeans Visual Web Pack.  But if you don't use one of those products, you probably didn't know it.  Well, now you don't have to use these tools to enjoy the rich JavaServer Faces components they provide.  In fact not only are they available outside these products, they are now Open Source!

Project Woodstock is the project which contains the source code for these components.  Both Creator's and NB VWP components were derived from earlier versions of this code base.  The code is released under the very flexible CDDL license.  These components have been in the making for over 2 years and have gone through several development cycles.  They're stable, full featured, and work seemlessly together sharing a common theme -- they're ready for production!

Let's take a look at what some of these components look like:

  • The CommonTasks component produces a page of common tasks for your application, complete with drop-down help and nice roll-over visual effects:

Common Tasks


  • This Table component can create simple to very complicated tables.  It takes advantage of the unique "DataProvider" feature that makes managing your data efficient and a breeze!  Below is a fairly complicated table: 




  • The Masthead component allows you to present a visual appealing and very functional masthead complete with status information, buttons, branding, and more: 


  • The Wizard component allows you to create web-based wizards for walking your user through a process:


  • The Tree component provides a both a server-side and client-side rendering option and nice visual appeal: 


  • The PropertySheet and FileChooser shown below are two more nifty components that provides a nice page layout and the ability to browse and select a file on the server: 


All of these components are "themed" so you can adapt the look of these components to your company's look and feel by creating your own theme.  Many of the components use Ajax (via Ed Burn's Dynamic Faces project), and more Ajax features are sure to come.  The TLD document and example application included in the project provide more than enough information to get you started.

If you're a Faclets user, Jason Lee is already working on creating a Facelets taglib for Woodstock.  And of course if you're a JSFTemplating user, I have full support for the Woodstock components built in... plus I have a simple example app on the site to get you started.  Plus, the entire GlassFish admin console (source here) is built using JSFTemplating and Woodstock components.  So whatever your JSF environment (NetBeans, Facelets, JSFTemplating), you'll be able to use these components.

So what are you waiting for?  Go download the components and try them out!



Wednesday Feb 07, 2007

Jive Clearspace is Great on GlassFish

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