- A Brief History Lesson
- ColdFusion Editions
- OK, But Why Should I Use It?
- ColdFusion and JSTL
- Integration Made Easy
- < a href="#ok-so-its-a-very-large-tag-libary-on-steroids">OK, So It's a Very Large Tag Library on Steroids?
- The Community
- But if We Invest in ColdFusion, How Can We Be Sure It Will Be Here Tomorrow?
Forget Ruby on Rails; in this article I outline why, as a Java developer, you should perhaps be looking to another technology closer to home to leverage your existing in-house skills and infrastructure. We'll briefly touch on some of the features of ColdFusion, the Java-EE-based application server from Adobe, and discuss why ColdFusion is more relevant today for Java developers than it has ever been.
A Brief History Lesson
ColdFusion is one of the older scripting languages, first introduced in 1995. It is a little-known fact that Microsoft was once interested in acquiring Allaire, the original creators of ColdFusion. When Allaire showed a lack of interest, Microsoft then went on to purchase another company whose product formed the basis of their ASP technology.
ColdFusion, which was an application server written in C++, underwent a complete overhaul a few years ago, most notably a rewrite in Java that has resulted in recent Java-based versions being labelled with the "MX" suffix.
ColdFusion comes in three editions that are available on Linux, UNIX, Windows, and Mac OS X: a free developer edition (restricted to two IP addresses and localhost), a standard edition, and an enterprise edition.
The standard edition is bundled with the JRun application server, one of the oldest J2EE application servers (with a long history), but access to the underlying application server is restricted. The enterprise version allows full access to the underlying application server, allowing you to deploy both ColdFusion and your ColdFusion applications as an EAR or WAR file on any of the supported J2EE application servers. The benefits of these applications include:
- Share Java EE sessions between ColdFusion and EE applications.
- Contain ColdFusion pages that include JSP pages, or vice versa (i.e., JSP pages that include ColdFusion pages).
- Call ColdFusion components from Java (more on ColdFusion components later).
- Create hybrid ColdFusion and Java applications that utilize ColdFusion and Java servlets for the presentation layer and POJOs or EJBs for the business services layer.
With the enterprise edition you can still capitalize on the enterprise scalability, transaction support, messaging, etc. built in to Java EE servers, and the knowledge of administration of these servers.
OK, But Why Should I Use It?
The most compelling reason to use ColdFusion is productivity. As with many dynamically typed scripting languages, there is no need to build, deploy, or restart your app server. ColdFusion pages are written in ColdFusion Markup Language (CFML), a tag-based markup language similar to JSP tags and JSTL. With it, you simply save and refresh your browser to view your latest changes. ColdFusion compiles .cfm pages into Java servlets in much the same way as JSP. However, compilation is done in memory and not to disk. The compiled class is then cached in memory for subsequent calls to the web page.
The second, and perhaps more pertinent, reason it is better suited to Java developers than other languages is that you can make seamless calls to all the built-in Java libraries, as well as those bundled with ColdFusion and any custom APIs of your own. All versions of ColdFusion have access to all of the core Java classes. ColdFusion is a Java EE application, allowing you to leverage existing Java libraries and code bases.
Much of the functionality available in ColdFusion is provided by the bundled Java APIs and products that Java developers are already familiar with, such as Apache Axis, JasperReports, log4J, iText, J-integra, and JBuddy, to name but a few. All of these are easily accessed using ColdFusion's simple tag-based language or its alternative scripting syntax, CFScript. CFScript is based on ECMAscript and is used by wrapping your code in
cfscript tags. Java developers in particular may feel more at home with this syntax.
The following example illustrates how Java classes are used in ColdFusion. To call a particular constructor from ColdFusion, there is a special method called
init() that should be called with the relevant arguments:
<cfscript> //to create an instance of a class calling a constructor... myObj = createobject("Java","Java.lang.Someclasss").init(some,args); someResult = myObj.someMethod(); </cfscript>
ColdFusion and JSTL
JSP developers will notice similarities between the syntax of JSTL and ColdFusion tags. Unlike JSTL, ColdFusion contains a much larger set of tags and almost 300 functions for string processing, date and time manipulation, encryption, XML, and more. Although you can use Java classes or libraries directly, using the built-in ColdFusion tags such as
CFMAIL make light work of many things such as creating PDF documents, retrieving remote files via FTP, and sending emails.
Sending an HTML email with the
CFMAIL tag, for example, is as simple as:
<cfmail from="email@example.com" to="firstname.lastname@example.org" subject="some subject" type="html"> <html> <head> <title>Our HTML newsletter</title> </head> <body> Who needs Ruby... </body> </html> <cfmail>
Just as simple is creating a PDF from an HTML document using the built-in
<cfdocument format="PDF" orientation="portrait"> <html> <head> <title>My html document</title> <link rel="stylesheet" type="text/css" href="style.css"> </head> <body> ... </body> </html> </cfdocument>
The following line is all that is needed to apply an XSL stylesheet to an XML document to perform a transformation:
<cfset myTransformedDoc = xmlTransform(originalXmldoc, XSLStylesheet) />
ColdFusion also has its own object-like constructs called ColdFusion Components (CFCs) that provide for encapsulation, inheritance, and polymorphism.
Integration Made Easy
ColdFusion has always been known for facilitating easy integration with other technologies such as CORBA, web services, and COM. For example, ColdFusion leverages Apache Axis for web service support.
<cfscript> //get a reference to webservice ws = createObject("webservice", "http://www.xmethods.net/sd/2001/DemoTemperatureService.wsdl"); //call method temperature = ws.getTemp(90210); //display temperature writeoutput(temperature); </cfscript>
Similarly, if you need to connect and call a COM object, the following code is all that is required:
<cfset myComObject = createObject("COM","excel.application.9") />
As you can see, to communicate with a COM object, there is no need to download or install a third-party API, providing ease of integration with Microsoft technologies.
Similar integration can be done on UNIX using ColdFusion Extension Tags(CFXes). CFXes provide a method of calling native code on Linux (as well as Windows). ColdFusion ships with a library, the CFX API, that is required when writing such tags. CFXes are, however, limited to ColdFusion editions running on UNIX and Windows.
The advantage of using ColdFusion for your integration is that you have a built-in, standard set of functions and tags that can be used to integrate with other technologies. There is no need to import another third-party library or learn yet another unfamiliar API.
Another interesting integration feature: ColdFusion has an adapter that enables direct communication between ColdFusion components and Adobe Flex. For those who have not heard of Flex 2 yet, it's is the latest version of the platform based on Flash for developing rich internet applications. The Flex platform consists of Flex builder (an IDE), Flex Data Services (FDS), and a free compiler. Using Flex, developers can build rich internet applications in MXML, a tag-based language. It should be noted that you do not need ColdFusion to integrate with Flex, as an adapter also exists for Java to talk to Flex directly.
Flex is beyond the scope of this article, but you can find more info on the Adobe website.
OK, So It's a Very Large Tag Library on Steroids?
ColdFusion is much more than just a tag library--many of the other features that would normally require third-party products or APIs are built in. There is an administrator to enable caching and scheduling of template execution, a built-in SMS gateway, and a bundled graphing engine. And once again, the advantage of having all of this functionality built in is that it frees developers to use standard libraries instead of having to use (and more importantly maintain) various versions of different third-party APIs. An important point to take away from this is that it is not a choice of Java + JSTL or ColdFusion + ColdFusion components; you can mix and match where you see fit, creating an architecture that suits your requirements.
The ColdFusion community has grown up too, with a growth in the popularity of frameworks such as Mach-ii (an implicit invocation framework), Fusebox, Model Glue, and ColdSpring, a dependency injection framework. There is also the open source project named ColdFusion on Wheels, modelled on Ruby on Rails. The ColdFusion community is embracing agile development and building applications that make use of common design patterns. Apache Struts can also be used with ColdFusion using ColdFusion for your views. Also, there are a number of sites such as www.cfpetmarket.com that contain ColdFusion framework versions of a pet-store application.
Finally with the free, open source CFEclipse, an Eclipse-based plugin fast becoming the de facto IDE for ColdFusion developers, many Java developers will feel right at home with the development tools. There is also a commercial Eclipse-based interactive debugger available called FusionDebug.
But if We Invest in ColdFusion, How Can We Be Sure It Will Be Here Tomorrow?
Twelve years later and having survived both Allaire and Macromedia's acquisition, it is unlikely ColdFusion will be fading away any time soon. Adobe is currently working on the next version, codenamed "Scorpio." In addition, there are alternative ColdFusion engines that can also run CFML, such as BlueDragonand Railo.
If you have brushed off ColdFusion in the past in favor of other complementary technologies, download the free developer's edition, look at some of the tutorials, and give it a second look. You might just realize what a good fit ColdFusion can be in the Java enterprise arena.
- Coldspringframework.org: ColdFusion dependency injection framework
- Introduction to using ColdFusion with Struts
- Reality Macromedia ColdFusion MX: J2EE Integration: Book on ColdFusion and J2EE integration
- CFEclipse: Home of the open source CFEclipse plugin
- BlueDragon: Alternative ColdFusion engine that also has a .NET edition
- Meet the makers conversation with Jeremy Allaire: Interview with one of the original creators of ColdFusion
- ColdFusion on Wheels: ColdFusion Ruby on Rails framework
- Flex features: Overview of Flex features