Redmond Developer News has published an interview with Dr. James Gosling, creator of the Java language, where among other things, he talks about JavaFX and  competing technologies. And he made a comment I can’t agree with. Here’s the quote from that interview:

Before even going into technical details explaining why this statement is wrong,  let me tell you that if someone would ask me to name a dozen of the most respected people in the industry, James Gosling would be one of them. Because of him, I live in a nice house and drive a nice car – I’ve been doing Java for the last 10 years.  If James had not invented Java, I’d be probably still working with PowerBuilder, writing that it’s the best thing since sliced bread. 

But let’s go to the essence of the accusations. Dr. Gosling does not attack the presentation and delivery abilities of Flash Player because Flash Player is today’s leading delivery mechanism  for rich Internet applications. He addresses network protocols, something that may not be as easy to argue. So let’s talk protocols.

In 2007, my colleague and I were invited by a financial company (a Java shop) to assess if they could create an Internet version of their trading application using Flex. They did not have any doubts the GUI part should be done in Flex and delivered to their customers by Flash Player. Using AJAX for such an application would be crazy.

Sun’s long history of ignoring Java as a platform for delivering Internet applications ruled Java applets out. A dancing Duke made his short appearance in 1995 and was forgotten by Sun for the next 10 years. Can you imagine Amazon or Google using Java as a front end for their applications? It’d be insane – they’d lose half of their customers trying to persuade them to use Java applets - each of them has different version of JRE and installing the right one requires a college degree in computers.  I hope this situation will change with the introduction of the Consumer JRE later this year, but we are not there yet.

Anyway, this financial company was not sure if the communication protocols offered by Flex were robust enough to provide reliable and guaranteed message delivery and could be extended to accommodate the specific needs of this application, such as adding the application-specific quality of service (QoS) information right to the packets sent over the network from the Flash client to Java server-side application. They wanted some other things too, such as message throttling in case of network congestion and more.

Flex offers a server-side piece called LiveCycle Data Services ES, which comes  with a couple of fast communication protocols: AMF – a binary protocol that makes calls over HTTP from client to server (polling), and RTMP – real time messaging protocol that supports real time push from the server to the Flash client.  By the way, AMF goes open source in a month or so (see BlazeDS).  Security is similar to Java applets (sandbox) and you can use RTMPS instead of RTMP. Java offers RMI protocol for RPC and JMS for messaging.  RTMP is easy to integrate with other messaging systems via JMS. RTMP is built using Java non-blocking IO and it supports the data push needed in most Web applications.

Under the hood,  AMF and RTMP protocols implement object serialization,  so an instance of a Java object gets serialized on one end and is re-created as an instance of the ActionScript object on the client inside Flash Player, which is nothing else but a VM. On the way back, an ActionScript object is serialized on the client and gets re-created in the server’s JVM as a Java object.

One of the most important features of the Flex framework is that it’s extendable. The server side of the implementation of these protocols is written in Java, and the client side in ActionScript 3. To make the story short, we were able to extend the communication channels, end points, message consumers and producers to enrich RTMP protocols to the client's specification. Now the messages about trading orders and executions travel happily between the Flash client and Java server.  We've also added a two-way RPC-over-messaging in a symmetrical way. 

This project was an example of a nice marriage between  Flex and Java in a Wall Street application. If Flex has weak spots, it’s slow compiler and a mediocre (by Java standards)  Eclipse-based IDE. Since Flex is open sourced now,  I hope that some third-party company will create a better IDE and improve the compiler.

But as of now, I’m pretty happy with using both Java and Flex technologies, and the good part is that it’s not an either-or situation – just use the right tools for the job. There is no need to lobby for any particular language. As for JavaFX, I wish it would start competing with Flex and Silverlight as soon as possible. The more the merrier.

Some time ago I said to my kids, “Even if, God forbid, you commit a crime, Mom and I will still love you and will try to protect you to the very end. You are our kids and we love you regardless of your achievements and personal qualities.” It seems that James Gosling has the same principles and protects his baby no matter what. I respect this but have my reservations.

James Gosling's fan,
Yakov Fain

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