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No, it has nothing to do with armed conflict. Making WAR files is the Java way of packaging, distributing, and deploying web applications. While JAR stands for “Java archive”, WAR stands for “Web application archive”, or simply “Web archive”. In fact, the JAR and WAR formats are both gzipped directories that include a manifest. While a JAR file typically contains a collection of class files, a WAR file contains the entire content that goes into a Java Web application. More precisely, a WAR file contains all the static content, directories, JSPs, beans and classes, libraries, as well as the web.xml deployment descriptor. If you unpack a WAR file, you get a directory structure that mirrors the document root of a deployed application in a web container, such as Tomcat. I recently had to create a Web application in Eclipse. I realised that despite having worked with Eclipse for five years, this is something I never did before, because in the past I used Netbeans for creating web applications. But it’s just as easy in Eclipse. Here are is how:

To create a Java web project, you need to have the following software installed: a Java JDK, a recent version of Eclipse that contains the WTP Web Tools Platform module for Eclipse, and a web container or an application server, such as Tomcat, JBoss, WebSphere, etc.

1…Select File/New/Project from the menu. The following dialogue appears:

2…Select Dynamic Web Project from the list and click on the Next button.

3…Type a name for the new project and select a file system location for it. In the Target Runtime option, specify the web container or application server you using. This server is used to build and deploy your web application. If the drop-down box does not contain the desired server, click New… and select one of the predefined configurations (see Step 4). If you have already defined a Target Runtime, you can skip ahead to Step 6. The Dynamic Web Module version option specifies the architecture you are going to use in the web project. Select the latest version for a new project. Unfortunately, this cannot be changed later. By clicking the Modify… button in the Configuration section, you can select “facets” for your web application. What Eclipse calls “facets” are various building blocks and APIs, such as Java Server Faces, Java Persistence API, etc., that add functionality to your application.

4…The New… button in the Target Runtime section opens a dialogue that lets you select the server on which the application is developed and deployed, which is probably the most important aspect of your configuration. Eclipse offers a number of common configurations for popular servers. If you cannot find your server in this list, click on the Download additional server adapters link and chances are that your server is listed. Make sure that the Create a new local server option is checked, so that you can find the server in the Eclipse server view later on.

5…Once you specified the server type, you need to provide some details about it, such as the installation directory of the server, or the server root, and the JRE you want the server to run on. Click Finish when done.

6…Finally, the dynamic web project wizard prompts you for some basic configuration data. The Context Root is the name that the web container matches with the  location where the application is deployed and simultaneously constitutes the root URL for the web application. The Content Directory specifies the name of the directory that contains the web application files. The Java Source Directory specifies the name of the directory that contains Java source code files. These settings are only relevant to the development machine. Make sure that the Generate deployment descriptor option is checked in order to automatically create the web.xml file. In most cases, you can probably accept the default settings and click Finish.

7…Voilá. You have created a web application, or rather the framework for its development in Eclipse. The new project should now be visible in the Navigator view. There aren’t any files yet, except the ones which were generated automatically by Eclipse. The next step would be to write your web application, and possibly incorporating the application framework of your choice. Piece of cake.

8…The Server view should display the server you have chosen for your project. If everything went OK, you can start and stop the server from this view. The server can be started in normal mode, debug mode, or profiling mode. Debug mode needs to be selected if you want to define breakpoints in your Java code. While you edit sources, such as JSP files, servlets, bean classes, static content, etc., Eclipse automatically redeploys these resources to the running server as soon as you save them. You can view your web application in a separate browser window and receive debug output in Eclipse’s Console view.

9…After you have written your formidable web application, it’s time to share it with the world, or in more technical terms, to distribute and deploy it. The process of creating a distributable WAR file is extremely simple. Select File/Export from the Eclipse menu and click on the WAR file option in the Web category.

10…After clicking the Next button, specify the web project to be packaged, the file destination, and the target server. Although the latter is not a mandatory option, it is probably an important one. The selected server is likely to be the same as the one chosen in Step 3. Click Finish and there you have your masterpiece in a handy WAR format.

Because HTML is at the very core of the World Wide Web, you would expect it to be a mature and refined technology. You would also expect it to provide a flexible platform for Web application development and deployment. As most web developers know, the reality is a bit different. HTML started out as a rather simple SGML application for creating hyperlinked documents. It originally provided a basic set of elements for data viewing, data input, and formatting, whereas it did a little bit of all, yet nothing quite right. While this was practical for whipping up quick-and-dirty websites, it proved to be inadequate for more demanding presentation tasks and fine-tuned user interaction. Thus a whole bunch of supplemental technologies came into being, including CSS, JavaScript, Flash and finally AJAX. You know the story. All of this was quite a messy affair and unfortunately it still is.

While the HTML 4.01 specification has ruled the Web since 1999, the fifth incarnation of HTML was released by the W3C as a working draft earlier this year and is constantly updated since then. The HTML 5 specification is supposed to pave the way for future Web standards. It contains an older draft of W3C dubbed “Web Forms 2.0”, which is W3C’s answer to Web 2.0 and the World Wide Web becoming a platform for distributed applications. Don’t expect anything too radical, though. It neither delivers the hailed “rich GUI” for the Internet, nor will it replace current technologies like AJAX. It is rather designed as a natural extension of the former. It provides good backward compatibility while smoothing some of the rough edges of HTML. No more no less. Let’s have a look at the new features in more detail.

HTML 5 mends the split between the preceding HTML 4 and XHTML 1.0 specifications. Rather than being defined in terms of syntactical rules, it makes the DOM tree its conceptual basis. Thus HTML 5 can be expressed in two similar syntaxes, the “traditional” one and the XML syntax, which both result in the same DOM tree. It goes far beyond the scope of previous specifications, for example by spelling out how markup errors are handled, rather than leaving it to browser vendors, and by specifying APIs for new and old elements. These APIs describe how scripting languages interact with HTML. So, what’s new? The following elements have been dropped from the specification:

• <acronym>
• <applet>
• <basefont>
• <center>
• <dir>
• <font>
• <frame>
• <frameset>
• <isindex>
• <noframes>
• <s>
• <small>
• <strike>
• <tt>
• <u>
• <xmp>

The following attributes are also goners:

abbr, accesskey, align, alink, axis, background, bgcolor, border, cellpadding and cellspacing, char, charoff, charset, classid, clear, compact, codebase, codetype, coords, declare, frame, frameborder, headers, height, hspace, language, link, marginheight and marginwidth, name, nohref, noshade, nowrap, profile, rules, rev, scope, scrolling, shape, scheme, size, standby, summary, target, text, type, valuetype, valign, version, vlink, width.

Some of these elements and attributes are quite obscure, so perhaps they won’t be missed. Others like <center>, align, background, and <u> were heavily used in the past, although most of these were already deprecated in HTML 4. The message here is clear: get rid of presentational markup and use CSS instead. The <b>, <i>, <em> and <strong> tags have miraculously survived, however. Although primarily used for text formatting in the past, these tags have been assigned new (non-presentational) semantics to make them respectable. Another conspicuous omission are frames. Yes, frames are gone! But you might breath a sigh of relief to know that <iframe> is still there. Speaking presentational versus semantic HTML, there are quite a few additions to HTML 5 in the latter category. The new semantic tags are designed to aid HTML authors in structuring text and to make it easier for search engine crawlers to parse information in web pages. Here they are (explanations provided by W3C):

• <section> represents a generic document or application section. It can be used together with h1-h6 to indicate the document structure.
• <article> represents an independent piece of content of a document, such as a blog entry or newspaper article.
• <aside> represents a piece of content that is only slightly related to the rest of the page.
• <header> represents the header of a section.
• <footer> represents a footer for a section and can contain information about the author, copyright information, et cetera.
• <nav> represents a section of the document intended for navigation.
• <dialog> can be used to mark up a conversation in conjunction with the <dt> and <dd> elements.
• <figure> can be used to associate a caption together with some embedded content, such as a graphic or video.
• <details> represents additional information or controls which the user can obtain on demand.

Most of these, except the last two, behave like the <div> element, which means their primary use is to identify a block of content that belongs together. Unlike <div> special semantics are associated with each of these elements. Not very exciting? HTML 5 also introduces the following new elements (explanations again from the W3C document):

• <audio> and <video> for multimedia content. Both provide an API so application authors can script their own user interface, but there is also a way to trigger a user interface provided by the user agent. Source elements are used together with these elements if there are multiple streams available of different types.
• <embed> is used for plugin content.
• <mark> represents a run of marked (highlighted) text.
• <meter> represents a measurement, such as disk usage.
• <time> represents a date and/or time.
• <canvas> is used for rendering dynamic bitmap graphics on the fly, such as graphs, games, et cetera.

The <embed> tag supersedes the <applet> and <object> tags. It defines some sort of embedded content that doesn’t expose its internal structure to the DOM tree. The content is typically rendered by a browser plugin. The <audio> and <video> tags are perhaps more interesting, because they make it possible to include multimedia files or streams directly into the HTML document without having to specify a vendor-specific plugin for playing the content. Granted, this could previously be done with the <embed> tag, but the <embed> tag was never a W3C standard and it isn’t supported by all browsers. Obviously, W3C has decided not to follow the mainstream browser implementations and added the <audio> and <video> tags instead, while reserving the <embed> tag for the above named purpose.

Arguably the most exciting additions to HTML 5 -at least from the perspective of a web developer- are the extensions to form processing and data rendering, and the related APIs, such as the editing API or the drag-and-drop API. These additions have previously evolved as a separate standard under the term Web Forms 2.0 and are now incorporated into HTML 5. The <input> element has been enhanced to support several new data types. New elements for user interface components have been defined, similar to those that can be found in GUI applications. For example, HTML 5 finally features the long awaited combo box, a combination of text input and drop-down list, which is a standard component in GUIs for decades. A new <datagrid> element for the interactive/editable representation of data in tabular, list, or tree form, is also present. Here are the new <input> types:

• type=”datetime”- a date and time (year, month, day, hour, minute, second, fraction of a second) with the time zone set to UTC.
• type=”datetime-local”- a date and time (year, month, day, hour, minute, second, fraction of a second) with no time zone.
• type=”date” - a date (year, month, day) with no time zone.
• type=”month” - a date consisting of a year and a month with no time zone.
• type=”week” - a date consisting of a year and a week number with no time zone.
• type=”time”- a time (hour, minute, seconds, fractional seconds) with no time zone.
• type=”number” - a numerical value.
• type=”range” - a numerical value, with the extra semantic that the exact value is not important.
• type=”email”- an e-mail address.
• type=”url” - an internationalised resource identifier.

The input element also has several new attributes in HTML 5 that enhance its functionality (many of these also apply to other form controls such as <select>, <textarea>, etc.):

• list=”listname” - used in conjunction with the <datalist> element to create a combobox.
• required - indicates that the user must provide an input value.
• autofocus - automatically focuses the control upon page load.
• form - allows a single control to be associated with multiple forms.
• inputmode - gives a hint to the user interface as to what kind of input is expected.
• autocomplete - tells the browser to remember the value when the user returns to the page.
• min - minimum value constraint.
• max - maximum value constraint.
• pattern - specifies pattern constraint.
• step - specifies step constraint.

The following new elements provide additional user interface components for web applications. The last three are actually not themselves UI components, but components used for scripting the UI through a server side language:

• <command> represents a command the user can invoke (e.g. toolbar button or icon).
• <datalist> together with the a new list attribute for input is used to create comboboxes.
• <output> represents some type of output, such as from a calculation done through scripting.
• <progress> represents a completion of a task, such as downloading or when performing a series of expensive operations.
• <menu> represents a menu. The element has three new attributes: type, label and autosubmit. They allow the element to transform into a menu as found in typical user interfaces as well as providing for context menus in conjunction with the global contextmenu attribute.
• <datagrid> represents an interactive representation of a tree list or tabular data.
• <ruby>, <rt> and <rb> allow for marking up Ruby annotations.
• <eventsource> represents a target that “catches” remote server events.
• <datatemplate>, <rule> and <nest> provide a templating mechanism for HTML.

Let’s briefly look at the new <datagrid> element. <datagrid> usually has a <table> child element, although <select> and <datalist> are also possible to create a tree control. The columns in the datagrid can have clickable captions for sorting. Columns, rows, and cells can each have specific flags, known as classes, which affect the functionality of the datagrid element. Rows are selectable and single cells (or all cells) can be made editable. A cell can contain a checkbox or values that can be cycled. Rows can also be separator rows. Datagrids have a DOM API for updating, inserting, and deleting rows or columns. They also have a data provider API that controls grid data content and editing.

I hope you found this brief overview useful. Please note that the features mentioned here don’t cover everything that is new in HTML 5, but hopefully they catch the essence. The HTML 5 specification is a work in progress; it is still changing and evolving. You can find the latest editor’s draft at http://www.w3.org/html/wg/html5/. An overview of the changes from HTML 4 is available at http://www.w3.org/TR/html5-diff/.

OpenID appears to be red hot right now. The adoption of this emerging standard has accelerated in the first half of 2008 as it has entered the radar screen of web developers. Many large organisations, such as Google, Yahoo, IBM, Microsoft and AOL provide OpenID servers. Popular Internet sites, such as LiveJournal, Blogger, Jabber, Drupal and Wikitravel support OpenID logins, and the list is growing. Browser support for OpenID is just around the corner (it’s a feature in Firefox 3 for example). But we are getting ahead of ourselves. What is OpenID and why is it good? Put simply, OpenID solves two common problems; that of having to manage multiple accounts on different websites and that of storing sensitive account information on websites you don’t control. With a single OpenID account you can log into hundreds of different websites. Best of it, you -the user- manage the account information, not the website owner. In more technical terms, OpenID is an open, decentralised, user-centric digital identity framework. I’ll explain this in some more detail.

OpenID is an open standard, because nobody owns it and because it’s free of patents and commercial licensing. The standard is maintained by the OpenID foundation; free open source implementations are available in many languages, including Java and PHP. It is decentralised, because it does not depend on a specific domain server. An existing OpenID provider can be rerouted very easily, as we shall see. It is user-centric, because it allows users to manage and control their identity information. Users can identify themselves with a URL they own. While traditional authentication relies on a combination of either a name or an email address and a password, OpenID just requires one item which is either a URL or an XRI (extensible resource identifier). To understand how this works, let’s look at the OpenID protocol and see what an OpenID login procedure actually does.

Let’s assume you already have an OpenID. You can use the same OpenID with any OpenID-enabled website (called the “relying party”) by typing it into the OpenID login field or by letting your browser fill out the field automatically. When you click Submit, the relying party performs a “discovery” procedure to retrieve an authentication URL and subsequently performs an “association” procedure for secure information interchange with the OpenID provider. You are then transported to the authentication URL (called the “OpenID provider”). Normally this is a site like yahoo.com or myopenid.com, but nothing keeps you from running your own OpenID server. After authenticating at the OpenID provider’s secure login page, you are redirected back to the relying party. If the relying party has requested identity information (name, gender, birth of date, etc.), you are prompted which information should be sent to the relying party. Often this information is used to fill in a registration form at the relying party. This information isn’t retrieved for a normal login, but the OpenID protocol supports it. Once you are back at the relying party’s website, the relying party checks whether the authentication was approved and verifies that the information is received correctly from the OpenID provider.

It sounds slightly complicated and by looking at the OpenID specifications you will find that the protocol is indeed quite involved. However, from the users point of view, it is really simple. The user only sees the OpenID login screen. If the user has enabled automatic login at the OpenID provider via a certificate or cookie, the only screen the user sees is the “approve/deny” screen. Logging into a website could not be easier. Only one password needs to be remembered. Registration forms can be pre-filled. Login into specific sites can be fully automated. The best thing is that the user has full control over the OpenID provider thanks to the discovery process. During discovery, the relying party looks for two fields in the header of the web page that it finds at the OpenID URL. In HTML Discovery, there are two fields named openid.server and openid2.provider. Example:

<link rel="openid.server" href="http://www.myopenid.com/server" />

 <link rel="openid2.provider" href="http://www.myopenid.com/server" />

These two entries commonly point to the same end point (the OpenID provider) and are used by version 1 and version 2 of the OpenID protocol. If you have a website, you could simply edit the HTML of your site to add these entries into the HTML header. You could then use the URL of that page as your OpenID. The advantage of using your own web page is that you control the OpenID end point. Hence, you can switch OpenID providers while retaining your OpenID simply by editing your site’s HTML code.

If you are going to incorporate OpenID into your existing website, you might want to think twice about implementing the protocol yourself. It isn’t trivial, and there are already several open source libraries that can be used, e.g. Openid4java if you program in Java, or the JanRain PHP OpenID library which works with PHP 4.3 up. Additional libraries for these two languages, as well as Ruby, Python, C#, C++, and other languages can be found at http://wiki.openid.net/Libraries.