Welcome!

You will be redirected in 30 seconds or close now.

ColdFusion Authors: Yakov Fain, Jeremy Geelan, Maureen O'Gara, Nancy Y. Nee, Tad Anderson

Related Topics: ColdFusion

ColdFusion: Article

Use the JavaMail API to Build an IMAP Custom Tag

Use the JavaMail API to Build an IMAP Custom Tag

Don't reinvent the wheel." We've all heard, and perhaps uttered, this maxim many times during our programming careers. ColdFusion MX has introduced new features to help CF developers avoid reinventing the wheel, including tag-based user-defined functions (UDFs) and ColdFusion components (CFCs).

As more CF developers begin to use these features, more code will be available for other developers to download and use. However, code reuse in ColdFusion is not limited to ColdFusion code. Integrating with Java is easier than ever with MX. Since the developer base for Java is large and it has been around much longer than ColdFusion UDFs and CFCs, there is a lot of code already out there that CF developers can use. I discovered this firsthand on a recent project when I didn't think about using existing Java libraries before starting down another path.

This project required me to programmatically access e-mail messages in a subfolder of an e-mail inbox. I couldn't use the CFPOP tag to do this because the protocol implemented by CFPOP - the "Post Office Protocol" - is designed to allow users to download messages from the "inbox" folder only. Another protocol is required to access subfolders - the Internet Message Access Protocol (IMAP).

After discovering that I needed to use IMAP to accomplish my task, I looked for a way to use it with ColdFusion. Unfortunately, since there is no built-in ColdFusion tag that implements IMAP, and I had been looking for an excuse to play around with Java, my first reaction was "Cool! I'll write my own!"

I learned a few IMAP commands and started playing around with the low-level Java networking libraries. Two days and many lines of code later, I had written a marginal IMAP client. Although it mostly worked, it still needed additional functionality and I wasn't at all confident in its stability. I knew there had to be a better way.

JavaMail API
Fortunately, I discovered that there is a much better way - use the JavaMail API. According to Sun's JavaMail Web site (http://java.sun.com/products/javamail), this API "provides a set of abstract classes that model a mail system" including support for IMAP - the same functionality (plus a lot more) that I had been struggling with for two days. Best of all, since it's included in the J2EE platform, on which ColdFusion MX is built, I didn't have to download anything or make any configuration changes to use it. This was the option I should have considered from the start.

Design Goals
Now that I had found a library, I wanted to make it simple to use from ColdFusion. Since I was already comfortable using the CFPOP tag, I decided to encapsulate some of JavaMail's functionality into a custom tag that, as much as possible, provides the same interface as CFPOP. The tag's full code is shown in the code listing. Listing 1 shows the functions that interact with the API.

Listing 2 shows the tag's main logic. For the sake of brevity, the code shown in the listing includes only one of the actions provided by CFPOP's interface - the "GETHEADERONLY" action. This excludes the "GETALL" action, which provides the ability to view a message's contents and attachments, and the "DELETE" action.

The Code
The JavaMail API consists of a bunch of classes that model a mail system. The highest-level class is the "Session" class. The session class allows you to specify properties like "port" and "timeout." To specify properties, first create and set a "Properties" object. The following sets the protocol to IMAP and the port to 143:

obj_Properties =
createObject("Java",
"java.util.Properties");
obj_Properties.init();
obj_Properties.put(
"mail.store.protocol",
"imap");
obj_Properties.put(
"mail.imap.port",
"143");

Now create the session object and pass in the properties object:

cls_Session =
createObject("Java",
"javax.mail.Session");
obj_Session =
cls_Session.getInstance(
obj_Properties);

The session class also provides a method for getting the "store." The store class abstracts the underlying protocol (in this case IMAP) and provides methods for logging into the mailbox.

obj_Store = createObject("Java",
"javax.mail.Store");
obj_Store =
obj_Session.getStore();
obj_Store.connect(
"my_mailserver",
"my_username",
"my_password");

Now you are ready to start accessing folders. The only folder that you can access using POP is the "inbox" folder. With IMAP, you can access subfolders below the inbox. The following code accesses and opens the folder "test," which is a subfolder of "inbox":

obj_Folder =
obj_Store.getFolder("inbox/test");
obj_Folder.open(
obj_Folder.READ_ONLY);

Note that this code opens the folder with read permissions only. This is a good idea if you only want to browse the contents of the folder. If you want to delete, move, or update messages, open the folder with read and write permissions:

obj_Folder.open(
obj_Folder.READ_WRITE);

The next step is to get a list of messages in the folder. With the JavaMail API, this is done by retrieving an array of "Message" objects.

ar_Messages =
obj_Folder.getMessages();

This code returns all messages in the folder. If you only need a subset of the messages, you must pass an array of message numbers to the "getMessages" function. Because I modeled my IMAP tag after the CFPOP tag, I wanted to allow the user to pass a list of message numbers to the tag. This discrepancy was easily remedied by using the built-in "ListToArray" ColdFusion function.

ar_Messages =
obj_Folder.getMessages(
ListToArray("1,2"));

Once you have the messages, you are ready to read the message headers using methods of the "Message" object. The following shows how to access the "subject" and "to addresses" of the first message in the folder (which is located at position 1 of the messages array):

// Get the received date
str_Subject =
ar_Messages[1].getSubject();

// Get the to addresses
cls_RecipientType =
CreateObject("Java",
"javax.mail.Message$RecipientType");
ar_To =
ar_Messages[1].getRecipients(
cls_RecipientType.TO);
lst_ToAddresses =
arrayToList(ar_To);

Note that the "getRecipients" method of the "Message" object returns an array of addresses since an e-mail message can be addressed to more than one person. This is also true when getting the "from", "reply-to", "CC", and "BCC" addresses. Also note the dollar sign ($) syntax used to invoke the "RecipientType" class. RecipientType is an "inner class" of the "Message" class. Although you can access inner classes in Java code by using dot notation (e.g., "Message.RecipientType"), this doesn't work in ColdFusion code.

Now that you have read the messages, the next step is to delete the unwanted ones. To do this, you set the "deleted" flag of the message and then call the folder object's "expunge" method:

cls_Flag =
CreateObject("Java",
"javax.mail.Flags$Flag");
ar_Messages[1].setFlag(
cls_Flag.DELETED,
true);
arguments.obj_Folder.expunge();

Where to Go from Here
The code presented here only scratches the surface of the functionality provided by IMAP. Most obviously, it lacks the ability to read message contents and attachments. Another useful feature would allow users to retrieve a listing of subfolders. If you are interested in adding these or other features, check out the JavaMail tutorial at http://developer.java.sun.com/developer/ onlineTraining/JavaMail/contents.html and the API specification at http://java.sun.com/products/ javamail/1.3/docs/javadocs/index.html.

Summary
With the release of MX, ColdFusion developers have more options for code reuse, including native access to a wide array of predeveloped Java software. Sometimes, especially for developers who don't have extensive Java experience, using existing Java libraries is not always the most obvious option. However, in ColdFusion MX, it can be a very worthwhile option to consider. It certainly is one that I strongly recommend the next time you start a project and think "Cool, I'll just write it myself..."

More Stories By Christian Thompson

Christian Thompson is a certified advanced Macromedia ColdFusion MX developer. He is a senior software engineer for Inserso, a technology consulting firm headquartered in Annandale, VA, where he has specialized in ColdFusion application development for over two years.

Comments (4) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


Most Recent Comments
Christian Thompson 05/27/03 10:53:00 AM EDT

As it is, the tag does not allow you to connect with NNTP servers. With a little configuration (getting and setting up an NNTP provider), though, JavaMail does. Once you got this set up, you would have create a tag similar to CF_IMAP that performs the necessary actions. I have included a link that talks a little about accessing NNTP servers with JavaMail.

Craig Rosenblum 05/26/03 11:17:00 PM EDT

Does this allow us to do nntp reading and posting?

Christian Thompson 05/12/03 02:25:00 PM EDT

According to the documentation, BlueDragon's CFIMAP implements the following actions: list folders, list messages, mark message as read, delete message, move message, delete folder, and move folder. Since the tag presented in this article currently only lists messages, you would need to add the rest of the functions. The good news is that they are all implemented in JavaMail. You would just need to write the CF code to call the functions.

Abraham 05/08/03 12:24:00 PM EDT

Nice article.

I'm planning to write a email app and want IMAP support.

I've been playing with BlueDragon lately, which offers a tag called CFIMAP. Would it take much extra code to get the same functionality?

@ThingsExpo Stories
Join IBM June 8 at 18th Cloud Expo at the Javits Center in New York City, NY, and learn how to innovate like a startup and scale for the enterprise. You need to deliver quality applications faster and cheaper, attract and retain customers with an engaging experience across devices, and seamlessly integrate your enterprise systems. And you can't take 12 months to do it.
Machine Learning helps make complex systems more efficient. By applying advanced Machine Learning techniques such as Cognitive Fingerprinting, wind project operators can utilize these tools to learn from collected data, detect regular patterns, and optimize their own operations. In his session at 18th Cloud Expo, Stuart Gillen, Director of Business Development at SparkCognition, will discuss how research has demonstrated the value of Machine Learning in delivering next generation analytics to im...
This is not a small hotel event. It is also not a big vendor party where politicians and entertainers are more important than real content. This is Cloud Expo, the world's longest-running conference and exhibition focused on Cloud Computing and all that it entails. If you want serious presentations and valuable insight about Cloud Computing for three straight days, then register now for Cloud Expo.
You think you know what’s in your data. But do you? Most organizations are now aware of the business intelligence represented by their data. Data science stands to take this to a level you never thought of – literally. The techniques of data science, when used with the capabilities of Big Data technologies, can make connections you had not yet imagined, helping you discover new insights and ask new questions of your data. In his session at @ThingsExpo, Sarbjit Sarkaria, data science team lead ...
So, you bought into the current machine learning craze and went on to collect millions/billions of records from this promising new data source. Now, what do you do with them? Too often, the abundance of data quickly turns into an abundance of problems. How do you extract that "magic essence" from your data without falling into the common pitfalls? In her session at @ThingsExpo, Natalia Ponomareva, Software Engineer at Google, will provide tips on how to be successful in large scale machine lear...
IoT device adoption is growing at staggering rates, and with it comes opportunity for developers to meet consumer demand for an ever more connected world. Wireless communication is the key part of the encompassing components of any IoT device. Wireless connectivity enhances the device utility at the expense of ease of use and deployment challenges. Since connectivity is fundamental for IoT device development, engineers must understand how to overcome the hurdles inherent in incorporating multipl...
The paradigm has shifted. A Gartner survey shows that 43% of organizations are using or plan to implement the Internet of Things in 2016. However, not just a handful of companies are still using the old-style ad-hoc trial-and-error ways, unaware of the critical barriers, paint points, traps, and hidden roadblocks. How can you become a winner? In his session at @ThingsExpo, Tony Shan will present a methodical approach to guide the holistic adoption and enablement of IoT implementations. This ov...
We’ve worked with dozens of early adopters across numerous industries and will debunk common misperceptions, which starts with understanding that many of the connected products we’ll use over the next 5 years are already products, they’re just not yet connected. With an IoT product, time-in-market provides much more essential feedback than ever before. Innovation comes from what you do with the data that the connected product provides in order to enhance the customer experience and optimize busi...
The IETF draft standard for M2M certificates is a security solution specifically designed for the demanding needs of IoT/M2M applications. In his session at @ThingsExpo, Brian Romansky, VP of Strategic Technology at TrustPoint Innovation, will explain how M2M certificates can efficiently enable confidentiality, integrity, and authenticity on highly constrained devices.
Artificial Intelligence has the potential to massively disrupt IoT. In his session at 18th Cloud Expo, AJ Abdallat, CEO of Beyond AI, will discuss what the five main drivers are in Artificial Intelligence that could shape the future of the Internet of Things. AJ Abdallat is CEO of Beyond AI. He has over 20 years of management experience in the fields of artificial intelligence, sensors, instruments, devices and software for telecommunications, life sciences, environmental monitoring, process...
SYS-CON Events announced today that Ericsson has been named “Gold Sponsor” of SYS-CON's @ThingsExpo, which will take place on June 7-9, 2016, at the Javits Center in New York, New York. Ericsson is a world leader in the rapidly changing environment of communications technology – providing equipment, software and services to enable transformation through mobility. Some 40 percent of global mobile traffic runs through networks we have supplied. More than 1 billion subscribers around the world re...
SYS-CON Events announced today that Stratoscale, the software company developing the next generation data center operating system, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. Stratoscale is revolutionizing the data center with a zero-to-cloud-in-minutes solution. With Stratoscale’s hardware-agnostic, Software Defined Data Center (SDDC) solution to store everything, run anything and scale everywhere...
Angular 2 is a complete re-write of the popular framework AngularJS. Programming in Angular 2 is greatly simplified – now it's a component-based well-performing framework. This immersive one-day workshop at 18th Cloud Expo, led by Yakov Fain, a Java Champion and a co-founder of the IT consultancy Farata Systems and the product company SuranceBay, will provide you with everything you wanted to know about Angular 2.
SYS-CON Events announced today that Men & Mice, the leading global provider of DNS, DHCP and IP address management overlay solutions, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. The Men & Mice Suite overlay solution is already known for its powerful application in heterogeneous operating environments, enabling enterprises to scale without fuss. Building on a solid range of diverse platform support,...
In his session at @ThingsExpo, Chris Klein, CEO and Co-founder of Rachio, will discuss next generation communities that are using IoT to create more sustainable, intelligent communities. One example is Sterling Ranch, a 10,000 home development that – with the help of Siemens – will integrate IoT technology into the community to provide residents with energy and water savings as well as intelligent security. Everything from stop lights to sprinkler systems to building infrastructures will run ef...
You deployed your app with the Bluemix PaaS and it's gaining some serious traction, so it's time to make some tweaks. Did you design your application in a way that it can scale in the cloud? Were you even thinking about the cloud when you built the app? If not, chances are your app is going to break. Check out this webcast to learn various techniques for designing applications that will scale successfully in Bluemix, for the confidence you need to take your apps to the next level and beyond.
Manufacturers are embracing the Industrial Internet the same way consumers are leveraging Fitbits – to improve overall health and wellness. Both can provide consistent measurement, visibility, and suggest performance improvements customized to help reach goals. Fitbit users can view real-time data and make adjustments to increase their activity. In his session at @ThingsExpo, Mark Bernardo Professional Services Leader, Americas, at GE Digital, will discuss how leveraging the Industrial Interne...
Whether your IoT service is connecting cars, homes, appliances, wearable, cameras or other devices, one question hangs in the balance – how do you actually make money from this service? The ability to turn your IoT service into profit requires the ability to create a monetization strategy that is flexible, scalable and working for you in real-time. It must be a transparent, smoothly implemented strategy that all stakeholders – from customers to the board – will be able to understand and comprehe...
Increasing IoT connectivity is forcing enterprises to find elegant solutions to organize and visualize all incoming data from these connected devices with re-configurable dashboard widgets to effectively allow rapid decision-making for everything from immediate actions in tactical situations to strategic analysis and reporting. In his session at 18th Cloud Expo, Shikhir Singh, Senior Developer Relations Manager at Sencha, will discuss how to create HTML5 dashboards that interact with IoT devic...
The increasing popularity of the Internet of Things necessitates that our physical and cognitive relationship with wearable technology will change rapidly in the near future. This advent means logging has become a thing of the past. Before, it was on us to track our own data, but now that data is automatically available. What does this mean for mHealth and the "connected" body? In her session at @ThingsExpo, Lisa Calkins, CEO and co-founder of Amadeus Consulting, will discuss the impact of wea...