Live CD for Developers

In this article, we write a web client for Twitter using NetBeans – the ready-to-use IDE bundled with the live CD.

Tuesday, March 03, 2009

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What are the IDEs (Integrated Development Environment) available for application development in the Open Source world? Here Open Source does not mean PHP only, nor does it mean Ruby or Java. Open Source here means all of them – Java, Ruby, PHP, C, C++ and what not.

Typically, there is an IDE for each language and/or technology. But IDEs like Eclipse and NetBeans have changed the game. From within the same IDE, you can develop, run, debug and deploy applications written in different technologies, languages or frameworks. PCQLinux live CD for developers bundles the full featured NetBeans IDE 6.5. You can boot off the live CD, fire the IDE, create a new project in one of your preferred languages/frameworks and do what you do the best – write code. The IDE assists you in the rest. Depending on the language and framework you use, NetBeans may facilitate your development efforts via RAD (Rapid Application Development) - quick drag-n-drop, build and run.

NetBeans makes it a breeze to write code for the latest in the Web 2.0 technology. To showcase the same, in this article we write a small web client in Java for Twitter. Twitter (www.twitter.com) is a popular micro blogging and social networking service. Twitter is used to share short information, in real time, with people you know or with the world.

The web client will use REST to show the direct messages sent to a (or your) Twitter account. Rest stands for Representational State Transfer and can be thought of a simplified form of web services (based on SOAP protocol). An introduction to REST can be found in the article 'SOAP and the REST' found at the URL http://pcquest.

ciol.com/content/search/showarticle.asp?arid=42818. Direct messages in Twitter are messages/ information sent speci fically to you by other Twitter user(s). Using the REST protocol we will retrieve the direct messages sent to a Twitter account and display it in a web page. This code can be extended and used, say, on your website or blog to show Twitter messages, inline with your site content.

Get, set and go
Boot off the live CD. While booting the live CD will prompt you to accept the NetBeans license. Press <space> to read through the license. Once read, press Y and ENTER to accept the license. To login, click on 'pcqlinux' and type in the password pass@word1. To launch NetBeans, click on Applications>Prog ramming>NetBeans IDE 6.5. Next, create a new project in Netbeans. Click on File>New Project. Select 'Java Web' in the Categories pane and then select 'Web Application' in the Project pane. Click on 'Next'. For the Project Name, type in TwitterClient. Click on 'Next'. In 'Server and Settings', select 'Personal GlassFish V3' for Server and click on 'Next'. For the Frameworks, select 'Visual Web JavaServer Faces' and click on 'Finish'. This will show up a page called Page1.jsp, in the middle pane, with tabs for design, JSP markup code and Java code

You can create new projects in Netbeans and select amongst a list of open source programming languages and frameworks. Whats more, NetBeans allows you to write desktop, web and mobile applications making it a one stop IDE and RAD tool.

Add the Twitter service
Click on the Java tab. To the class named Page1, add a new method named getTweets, as follows:

protected void getTweets()
{
}

You will need to call the above method in the init() method. In this method add the statement this.getTweets(); below the comment which says:

// TODO - add your own initialization code here

Click on the Services tab (on the left pane). Expand the 'Web Services' node. Next, expand Twitter>What Are You Doing Service>[direct_message .{format}]. Drag and drop getDirectMessagesToMe to the getTweets method body – i.e. drop it between the opeing ({) and the closing (}) braces. A window called 'Customize GET Saas Service' will pop up. Click on 'Ok' on this window. NetBeans will automatically create all the required code to consume the REST web service. Next we only require to write a few lines of code to display the direct messages on the web page.

Display the Tweets
Switch to the design mode by clicking on the Design tab. From the palette, in the right pane, expand Woodstock Basic. Drag and drop 'Static Text' component onto the design. Right click on the 'Static Text' component and select 'Add Binding Attribute'. Next, in the Java code, add the following import statements at the top:

import java.util.List;

Add the following statement just above the closing braces of the try block of getTweets( ) method:

this.displayTweets(result);

With this, we will pass the result of the web service call to another method called displayTweets where we will parse through the result/response of the service and display it.The code for displayTweets() looks like this:

protected void displayTweets(RestResponse result) throws JAXBException
{
twitter.whatareyoudoingservice.twitterresponse.DirectMessages directMessagesObject = result.getDataAsObject(twitter.whatareyoudoingservice.twitterresponse.DirectMessages.class);
this.staticText1.setText("");
this.staticText1.setEscape(false);
List<twitter.whatareyoudoingservice.twitterresponse.DirectMessageType> directMessages = directMessagesObject.getDirectMessage();
twitter.whatareyoudoingservice.twitterresponse.DirectMessageType directMessage = null;
for(int i=0;i<directMessages.size();i++)
{
directMessage = directMessages.get(i);
this.staticText1.setText(this.staticText1.getText()+"<br />"+directMessage.getSenderScreenName()+":"+directMessage.getText());
}
}

Add the above method to the Page1 class.

Run the application by clicking on Run>Run Main Project. When prompted, enter a Twitter username and password (using which you login at Twitter.com). The output will show sender and the direct tweets.

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