The first day of JavaOne proper (or the second day if you include CommunityOne on Monday) started with a two hour General Session.
A brief documentary showing the parallels between a 14 year old boy named Justin and 14 year old Java set the tone for the session. Each year from 1996, a different facet of Java has come to the fore. And in 2009, just as Java turned 14, the 14 year old boy was introduced as a gamer and Java developer. Sun is appealing to a new generation of developers now, and the emphasis on JavaFX reflects a generational shift in more ways than one.
Jonathan Schwartz, Sun's CEO, came up on stage next, and was the MC for almost the rest of the session. I have always been impressed by Schwartz for the direction he has given Sun as CEO, and I was impressed by his poise, confidence and easy manner as he conducted the proceedings. He did goof up a bit, though. He announced the release of Java 7 as of today, but it turned out later that it was just a milestone release. The final release of Java 7 isn't due till early 2010.
The theme for the morning was the power of a simple idea - to wit, "Write Once, Run Anywhere (WORA)".
An impressive array of customers and business partners trooped up to join Schwartz one after the other, all testifying to the wonderful goodies that Java technology had delivered to their organisations.
First up was James Baresse (VP Architecture, Platforms and Systems, eBay). eBay uses the integrated Java stack to run their business - the application framework, content management, batch systems and SOA.
Next in the witness box was Alan Brenner (Senior VP for the BlackBerry platform at RIM). For those who don't know already, the BlackBerry is a Java phone. RIM uses Java end-to-end - the core apps, the development platform, the works. Brenner showed off a third party app called Zavnee that integrates with the BlackBerry's email and phonebook APIs as well as community sites to provide a more insightful address book. According to Brenner, the open APIs of BlackBerry allow ISVs to build applications that integrate tightly with the device.
Don Eklund (Executive VP of Advanced Technologies at Sony Pictures Home Entertainment) came up to crow about the victory of Blu-Ray over its competition, or so it seemed to me. I'm not a great fan of Sony, which represents evil media. Eklund sang the praises of Java's openness. I couldn't help mentally completing his statement. Every company loves it when its building blocks are open and free, and when their own products are closed and proprietary. How about opening up the Blu-Ray format to everyone, Sony?
Lowell McAdam (President and CEO, Verizon Wireless) spoke about Verizon's Open Development Initiative last year that dealt with hardware, and their Open Development for Applications this year that deals with software. Verizon is opening up its APIs to enable third party developers to exploit functions such as presence, location, friends and family, etc.
Diane Bryant (Executive VP and CIO at Intel) talked about the collaboration between Intel and Sun to deliver high Java performance on the Intel platforms (Atom, Core and Xeon). They claim to have achieved an 8x raw performance improvement since 2006.
The final partner to come up on stage was Paul Ciciore (Chief Technologist at the Chicago Board Options Exchange). The CBOE is the world's largest options exchange, but it's a relatively new company. The Java-based implementation was conceived in 1998 and launched in 2001. From 5000 transactions per second in 2001, CBOE has grown to 300,000 transactions per second in 2009. They're also driving latency down lower and lower.
The next phase of the General Session talked about what I would characterise as an attempt by Sun to shift gears and start to provide the technology tools for applications that deal with media content in addition to those for the traditional enterprise applications that have been its mainstay so far. It's a risky gambit for Sun, and I'm not very optimistic about their chances of success. As an example, if Adobe trivially reengineers Flex to generate JVM bytecode, it's bye-bye, JavaFX.
There were some nifty demos of JavaFX applications, including one that ran on an HDTV set. There was another demo by Sun's Director of Engineering for the JavaFX platform, Nandini Ramani (wrongly pronounced (what else?) Ramaani). She showed off a nifty development environment for JavaFX that allowed content to be edited and targeted simultaneously for different devices. There's no compile-build cycle for JavaFX, this being a scripting language.
James Gosling, the inventor of Java, then came up on stage. This is one person I put in the same category as Bob Metcalfe, the inventor of Ethernet. Both are technology geniuses who have an astonishing blind spot about Open Source. [Metcalfe once famously referred to it as "Open Sores".] Gosling made a snide remark about how the Linux platform doesn't let developers build applications for it unless they're willing to make it a labour of love. His self-styled mission is to help developers convert a labour of love into a day job that puts food on the table. That's all very well, but someone should tell him that Open Source works very well as it is, thank you very much. It's a benign pyramid scheme, where a new generation of programmers comes along to build the next layer of an open platform on top of the last. The commoditisation continues up the stack. Too bad for people wanting to make money along the way. But that's not a problem for Open Source, nor is it a problem for the world. It's only in Gosling's (and Metcalfe's) world that a failure to monetise something equates to failure, period.
Gosling presented the Duke's Choice award to Mark Gerhard (CEO of Jagex, maker of the popular RuneScape game). About 20% of Jagex's users are paying customers. RuneScape will be available on the Java Store that I wrote about earlier. The Java Store provides tools to "ingest" and "distribute" applications, and Sun is still working on a suitable cash register implementation to enable effective commercialisation. Suggestions from the community are welcome...
Randy Bryant (Dean of Computer Science at Carnegie Mellon University) received another Duke's Choice award from Gosling on behalf of Randy Pausch, the inventor of the Alice Project. Alice, like MIT's Scratch, is a means of teaching computer programming to kids. Alice 3 goes a step further by introducing kids to Java programming, which Scratch doesn't do. [I'm planning to introduce Alice to my twelve year old.]
Somewhere along the way, Scott McNealy, Sun's chairman and former CEO, came up on stage. I have previously referred to McNealy as a dinosaur, and I must say that he literally looked and sounded old. Gone was the youthful "puckish humour" that magazines used to refer to. He seemed resigned to an imminent retirement. Reading between the lines, though he made some condescending remarks to Jonathan Schwartz about the wonderful way he had led the company even though he was a relative newcomer, I sensed some resentment and disapproval. I guess it's an open secret that Schwartz preferred an IBM takeover of Sun, and McNealy won out with the Oracle deal. I wonder how long Schwartz will last with Oracle CEO Larry Ellison as his boss. Open sourcing Java was the best thing Schwartz has done for the world, and must have turned Ellison's dreams of monetisation to ashes.
The piece de resistance of the morning's session was then the surprise introduction of Ellison himself.
Ellison said many nice things about Java (e.g., "Except for the database, everything at Oracle is Java-based"). Again, I was tempted to complete his sentence that "Java was attractive to us because it was open" with the clincher "and because it has allowed us to close everything we build above it". I hope the emerging Open Source enterprise stack eats Oracle's lunch in the coming recession.
Ellison said a few things that I found very significant. He wanted to see OpenOffice being redeveloped using JavaFX. He's now in a position to drive that initiative through investment, and something tells me he'll do it. It's more than just his traditional hatred of Microsoft. There's probably a big support subscription-based revenue stream that will come from the corporate market when OpenOffice supplants MS-Office.
Ellison also pledged not to make changes to the Java model but to "expand investment" in it, a commitment that drew relieved applause from the mostly geek audience. I guess there's indirect benefit to Oracle from Java's success, largely from its ability to prevent competitors from succeeding with their proprietary equivalents.
In another very significant statement, Ellison also hinted that Sun and Oracle would jointly introduce a mobile device to compete with devices running Google's Android. I think JavaFX is the weapon that Oracle-Sun are betting on.
Someone (I forget whether it was Gosling or someone else) also made a snide remark about Ajax that made me prick up my ears. I have previously wondered on this blog why people even bother with RIA tools like Flash, Silverlight and JavaFX when Ajax/DHTML is getting to be so much more capable. I realise now that I've been looking at it from the viewpoint of the community at large. From the viewpoint of Sun (and now Oracle), there is a silent and desperate struggle for survival going on. If Ajax succeeds, it will further reduce the relevance of these vendors. JavaFX is critically important to Sun. It's irrelevant to the world.
The second session I attended was "Deploying Java Technology to the Masses: How Sun deploys the JavaFX runtime" by Thomas Ng from Sun.
My major grouse against JavaFX is that it still isn't available for the Linux platform. Nigel Eke commented on my earlier blog post that Sun was going to announce Linux support for JavaFX at JavaOne, but it hasn't happened yet.
Very briefly, Ng's talk covered the following points - the deployment mechanism is JNLP, pioneered by Java Web Start almost a decade ago. There's a tool called the JavaFX Packager that is bundled with the JavaFX SDK. This helps to automate the creation of JNLP files, which is otherwise an error-prone undertaking. In future, the same tool will be used to create JNLP-based launchers for applets and Java Web Start applications, but as of today, that's still on the wishlist.
A potentially very useful feature (albeit a potential security headache) is the ability of the JavaFX runtime to permit cross-domain XML traffic. This removes the crippling constraint that prevents current-generation browser applications from reaching back to any servers but their own to make service calls.
A future version of JNLP will also remove the current requirement for an absolute "codebase" URI in the jnlp tag. This relaxation will make applications more readily portable between servers.
The next session was another General Technical Session hosted by Robert Brewin (Distinguished Engineer, VP and CTO for Application Platform Software at Sun). It was called "Intelligent Design: The Pervasive Java Platform".
[My "Press/Analyst" badge entitled me to special seating at the front of the hall, but since the perk didn't come with a table for my laptop, I declined the honour and chose to sit in the bleachers with a mortal friend.]
Items in brief:
Project Kenai allows developers to collaborate, share and engage. It seems to be a richer version of CVS or Subversion as a repository, because it has some of the characteristics of a social networking site. It will soon include continuous integration capabilities through its incorporation of the Hudson continuous build tool.
JDK 7 (prematurely announced by Jonathan Schwartz) will feature 3 things when it debuts - a modular platform, a multilingual VM and productivity enhancements for developers.
A new dependency information file format for classes means that "the classpath is dead", a statement that drew cheers. This diagram shows the new packages in Java 7, and their dependencies.
It will also make it easier to create deployment packages for various target platforms (such as .deb files for Ubuntu Linux).
There is a project called the "Da Vinci Machine" to enable the Java VM to be a true multi-language VM. For the first time in a decade, there will be new bytecode that will effectively upgrade the JVM architecture.
Then there's the cheekily-named Project Coin, which deals with small change(s) to Java.
Many minutes were wasted on a description of JEE 6. I have never understood the rationale for some of the components of JEE, and why Sun insists on throwing good money after bad. There's JSF 2.0 and EJB 3.1. The EJB cancer has reached Java's lymph nodes and is now threatening to infect healthy web server tissue through "Lite EJB", which can be bundled inside .war files and does not require .ear files or a heavyweight container. Why, why, why??? I thought Spring framework chemotherapy had forced EJB into remission, but this seems much more virulent than I thought.
Bean validation (JSR 303) seems to be a way to ensure consistent data validation across tiers (through JSF in the presentation tier and JPA in the persistence tier). I can't help thinking this is just the Java version of XForms. XForms carries an XML document payload that is defined through a schema that can then be used to validate this instance data in any tier.
There's a lot of emphasis on the Glassfish server that I just can't understand. Again, it's probably critical for Sun to own an application server that isn't just Tomcat+Spring. It just isn't that relevant to the rest of the world. Glassfish has ambitions of being scalable, "from embedded to carrier-grade".
One corollary of a more modular Java that I deduced and that Sun acknowledged is that in the future, there will be just one Java. No more ME, SE and EE variants.
I next attended a rather boring and depressing session that was optimistically called "Tips and Tricks for Ajax Push and Comet Apps". This was conducted by Jean-François Arcand of Sun and Ted Goddard of ICEsoft Technologies. It was depressing because at the end of the day, there seems to be no satisfactory method to implement server push that will scale well and work on all browsers. The lecture was a tour of various unsatisfactory compromises. The three standard techniques (Polling, Ajax push (long polling) and HTTP Streaming) all have their drawbacks. I personally like HTTP Streaming with its chunked response (multiple as-and-when partial responses to a single request). However, this doesn't seem to work very well in practice because of the lack of a client-side API for reading such an input stream, and the tendency for proxies to cache responses instead of passing them on, incomplete though they may be.
My conclusion is that push is impossible with HTTP. We need to implement AMQP over TCP for true bidirectional messaging. It will take time, but it will happen within a decade. And then these problems (and their kludgy solutions) will seem laughable in retrospect.
The last session that I attended was "Spring Framework 3.0: New and Notable" by Rod Johnson himself. The hall was huge but absolutely packed.
Points in brief:
Spring 3.0 will use Java 5+. Anyone wishing to use Java 1.4 must remain with Spring 2.5. Three cheers for courage. Backward-compatibility is a two-edged sword, and I'm glad Spring has made the leap (no pun intended).
There is a new expression language (EL) that allows developers to navigate bean properties, invoke methods and allow construction of value objects. It also allows us to parameterise annotated code:
@Value("#{systemProperties.favoriteColor}")
private String favoriteColor;
where the term within "#{}" is in the EL.
There is an elegant implementation of REST based on Spring MVC (and what was unsaid was that it was not based on JAX-RS). The Spring MVC ViewResolver is a natural point to implement the various resource representations that REST provides a common interface to.
There are several MVC enhancements. @RequestHeader provides access to HTTP request headers. @CookieValue provides access to cookies. It's also possible to have application-specific annotations.
There is a new Java configuration mechanism. Annotations can now be placed in dedicated "configuration classes" rather than in POJOs themselves. In other words, these are XML files all over again, but in Java 5 syntax rather than using angle brackets. I like this, because I was uneasy about annotations. One of the major benefits of externalising configuration is the ability to decouple wiring from the application's own components and make it possible to substitute implementations without recompiling code. Annotations in code are a step backwards, from this viewpoint. Annotations in dedicated configuration classes are three-quarters of a step forward again. We still need a recompile, but only of the config classes.
Rod Johnson pointed out that previous versions of Spring had a rather ad hoc approach to the web side of an application, but that Spring 3.0 now features a consistent stack of components. The base is Spring MVC. Above this layer are Spring Web Flow, Spring Blaze DS (for Flex) and Spring JavaScript. At the top layer is Spring Faces (ugh!). Spring Blaze DS will make it very easy to build Flex apps with Spring. The diagram made no mention of Spring Portlet MVC, which is perhaps just as well. [The portlet specification is another monstrosity that continues to give organisations grief. As an "integration" technology, it belongs more in the problem space than in the solution space.]
The Spring Java config mechanism is type-safe and does not depend on string names. It therefore has more robust bean-to-bean dependencies. It allows inheritance of configuration. And it allows object creation using arbitrary method calls.
Johnson also introduced Spring Roo, the Domain-Driven Design tool and Ben Alex's brainchild. There is a major functional overlap between Roo and Grails, which Johnson did point out, but his logical flowchart to decide which one to use was a bit contrived, in my opinion. Roo and Grails are competitors, and the fact that they are uncomfortable co-components in the Spring portfolio does not make them part of a seamless product line with an implied "horses for courses" decision-making logic. To put it bluntly, if Roo had appeared a couple of years earlier, Grails would probably have been stillborn. The delay in Roo's release gave Grails its break, and now they're competing for developer mindshare. Well, may the best framework win.
A brief documentary showing the parallels between a 14 year old boy named Justin and 14 year old Java set the tone for the session. Each year from 1996, a different facet of Java has come to the fore. And in 2009, just as Java turned 14, the 14 year old boy was introduced as a gamer and Java developer. Sun is appealing to a new generation of developers now, and the emphasis on JavaFX reflects a generational shift in more ways than one.
Jonathan Schwartz, Sun's CEO, came up on stage next, and was the MC for almost the rest of the session. I have always been impressed by Schwartz for the direction he has given Sun as CEO, and I was impressed by his poise, confidence and easy manner as he conducted the proceedings. He did goof up a bit, though. He announced the release of Java 7 as of today, but it turned out later that it was just a milestone release. The final release of Java 7 isn't due till early 2010.
The theme for the morning was the power of a simple idea - to wit, "Write Once, Run Anywhere (WORA)".
An impressive array of customers and business partners trooped up to join Schwartz one after the other, all testifying to the wonderful goodies that Java technology had delivered to their organisations.
First up was James Baresse (VP Architecture, Platforms and Systems, eBay). eBay uses the integrated Java stack to run their business - the application framework, content management, batch systems and SOA.
Next in the witness box was Alan Brenner (Senior VP for the BlackBerry platform at RIM). For those who don't know already, the BlackBerry is a Java phone. RIM uses Java end-to-end - the core apps, the development platform, the works. Brenner showed off a third party app called Zavnee that integrates with the BlackBerry's email and phonebook APIs as well as community sites to provide a more insightful address book. According to Brenner, the open APIs of BlackBerry allow ISVs to build applications that integrate tightly with the device.
Don Eklund (Executive VP of Advanced Technologies at Sony Pictures Home Entertainment) came up to crow about the victory of Blu-Ray over its competition, or so it seemed to me. I'm not a great fan of Sony, which represents evil media. Eklund sang the praises of Java's openness. I couldn't help mentally completing his statement. Every company loves it when its building blocks are open and free, and when their own products are closed and proprietary. How about opening up the Blu-Ray format to everyone, Sony?
Lowell McAdam (President and CEO, Verizon Wireless) spoke about Verizon's Open Development Initiative last year that dealt with hardware, and their Open Development for Applications this year that deals with software. Verizon is opening up its APIs to enable third party developers to exploit functions such as presence, location, friends and family, etc.
Diane Bryant (Executive VP and CIO at Intel) talked about the collaboration between Intel and Sun to deliver high Java performance on the Intel platforms (Atom, Core and Xeon). They claim to have achieved an 8x raw performance improvement since 2006.
The final partner to come up on stage was Paul Ciciore (Chief Technologist at the Chicago Board Options Exchange). The CBOE is the world's largest options exchange, but it's a relatively new company. The Java-based implementation was conceived in 1998 and launched in 2001. From 5000 transactions per second in 2001, CBOE has grown to 300,000 transactions per second in 2009. They're also driving latency down lower and lower.
The next phase of the General Session talked about what I would characterise as an attempt by Sun to shift gears and start to provide the technology tools for applications that deal with media content in addition to those for the traditional enterprise applications that have been its mainstay so far. It's a risky gambit for Sun, and I'm not very optimistic about their chances of success. As an example, if Adobe trivially reengineers Flex to generate JVM bytecode, it's bye-bye, JavaFX.
There were some nifty demos of JavaFX applications, including one that ran on an HDTV set. There was another demo by Sun's Director of Engineering for the JavaFX platform, Nandini Ramani (wrongly pronounced (what else?) Ramaani). She showed off a nifty development environment for JavaFX that allowed content to be edited and targeted simultaneously for different devices. There's no compile-build cycle for JavaFX, this being a scripting language.
James Gosling, the inventor of Java, then came up on stage. This is one person I put in the same category as Bob Metcalfe, the inventor of Ethernet. Both are technology geniuses who have an astonishing blind spot about Open Source. [Metcalfe once famously referred to it as "Open Sores".] Gosling made a snide remark about how the Linux platform doesn't let developers build applications for it unless they're willing to make it a labour of love. His self-styled mission is to help developers convert a labour of love into a day job that puts food on the table. That's all very well, but someone should tell him that Open Source works very well as it is, thank you very much. It's a benign pyramid scheme, where a new generation of programmers comes along to build the next layer of an open platform on top of the last. The commoditisation continues up the stack. Too bad for people wanting to make money along the way. But that's not a problem for Open Source, nor is it a problem for the world. It's only in Gosling's (and Metcalfe's) world that a failure to monetise something equates to failure, period.
Gosling presented the Duke's Choice award to Mark Gerhard (CEO of Jagex, maker of the popular RuneScape game). About 20% of Jagex's users are paying customers. RuneScape will be available on the Java Store that I wrote about earlier. The Java Store provides tools to "ingest" and "distribute" applications, and Sun is still working on a suitable cash register implementation to enable effective commercialisation. Suggestions from the community are welcome...
Randy Bryant (Dean of Computer Science at Carnegie Mellon University) received another Duke's Choice award from Gosling on behalf of Randy Pausch, the inventor of the Alice Project. Alice, like MIT's Scratch, is a means of teaching computer programming to kids. Alice 3 goes a step further by introducing kids to Java programming, which Scratch doesn't do. [I'm planning to introduce Alice to my twelve year old.]
Somewhere along the way, Scott McNealy, Sun's chairman and former CEO, came up on stage. I have previously referred to McNealy as a dinosaur, and I must say that he literally looked and sounded old. Gone was the youthful "puckish humour" that magazines used to refer to. He seemed resigned to an imminent retirement. Reading between the lines, though he made some condescending remarks to Jonathan Schwartz about the wonderful way he had led the company even though he was a relative newcomer, I sensed some resentment and disapproval. I guess it's an open secret that Schwartz preferred an IBM takeover of Sun, and McNealy won out with the Oracle deal. I wonder how long Schwartz will last with Oracle CEO Larry Ellison as his boss. Open sourcing Java was the best thing Schwartz has done for the world, and must have turned Ellison's dreams of monetisation to ashes.
The piece de resistance of the morning's session was then the surprise introduction of Ellison himself.
Ellison said many nice things about Java (e.g., "Except for the database, everything at Oracle is Java-based"). Again, I was tempted to complete his sentence that "Java was attractive to us because it was open" with the clincher "and because it has allowed us to close everything we build above it". I hope the emerging Open Source enterprise stack eats Oracle's lunch in the coming recession.
Ellison said a few things that I found very significant. He wanted to see OpenOffice being redeveloped using JavaFX. He's now in a position to drive that initiative through investment, and something tells me he'll do it. It's more than just his traditional hatred of Microsoft. There's probably a big support subscription-based revenue stream that will come from the corporate market when OpenOffice supplants MS-Office.
Ellison also pledged not to make changes to the Java model but to "expand investment" in it, a commitment that drew relieved applause from the mostly geek audience. I guess there's indirect benefit to Oracle from Java's success, largely from its ability to prevent competitors from succeeding with their proprietary equivalents.
In another very significant statement, Ellison also hinted that Sun and Oracle would jointly introduce a mobile device to compete with devices running Google's Android. I think JavaFX is the weapon that Oracle-Sun are betting on.
Someone (I forget whether it was Gosling or someone else) also made a snide remark about Ajax that made me prick up my ears. I have previously wondered on this blog why people even bother with RIA tools like Flash, Silverlight and JavaFX when Ajax/DHTML is getting to be so much more capable. I realise now that I've been looking at it from the viewpoint of the community at large. From the viewpoint of Sun (and now Oracle), there is a silent and desperate struggle for survival going on. If Ajax succeeds, it will further reduce the relevance of these vendors. JavaFX is critically important to Sun. It's irrelevant to the world.
The second session I attended was "Deploying Java Technology to the Masses: How Sun deploys the JavaFX runtime" by Thomas Ng from Sun.
My major grouse against JavaFX is that it still isn't available for the Linux platform. Nigel Eke commented on my earlier blog post that Sun was going to announce Linux support for JavaFX at JavaOne, but it hasn't happened yet.
Very briefly, Ng's talk covered the following points - the deployment mechanism is JNLP, pioneered by Java Web Start almost a decade ago. There's a tool called the JavaFX Packager that is bundled with the JavaFX SDK. This helps to automate the creation of JNLP files, which is otherwise an error-prone undertaking. In future, the same tool will be used to create JNLP-based launchers for applets and Java Web Start applications, but as of today, that's still on the wishlist.
A potentially very useful feature (albeit a potential security headache) is the ability of the JavaFX runtime to permit cross-domain XML traffic. This removes the crippling constraint that prevents current-generation browser applications from reaching back to any servers but their own to make service calls.
A future version of JNLP will also remove the current requirement for an absolute "codebase" URI in the jnlp tag. This relaxation will make applications more readily portable between servers.
The next session was another General Technical Session hosted by Robert Brewin (Distinguished Engineer, VP and CTO for Application Platform Software at Sun). It was called "Intelligent Design: The Pervasive Java Platform".
[My "Press/Analyst" badge entitled me to special seating at the front of the hall, but since the perk didn't come with a table for my laptop, I declined the honour and chose to sit in the bleachers with a mortal friend.]
Items in brief:
Project Kenai allows developers to collaborate, share and engage. It seems to be a richer version of CVS or Subversion as a repository, because it has some of the characteristics of a social networking site. It will soon include continuous integration capabilities through its incorporation of the Hudson continuous build tool.
JDK 7 (prematurely announced by Jonathan Schwartz) will feature 3 things when it debuts - a modular platform, a multilingual VM and productivity enhancements for developers.
A new dependency information file format for classes means that "the classpath is dead", a statement that drew cheers. This diagram shows the new packages in Java 7, and their dependencies.
It will also make it easier to create deployment packages for various target platforms (such as .deb files for Ubuntu Linux).
There is a project called the "Da Vinci Machine" to enable the Java VM to be a true multi-language VM. For the first time in a decade, there will be new bytecode that will effectively upgrade the JVM architecture.
Then there's the cheekily-named Project Coin, which deals with small change(s) to Java.
Many minutes were wasted on a description of JEE 6. I have never understood the rationale for some of the components of JEE, and why Sun insists on throwing good money after bad. There's JSF 2.0 and EJB 3.1. The EJB cancer has reached Java's lymph nodes and is now threatening to infect healthy web server tissue through "Lite EJB", which can be bundled inside .war files and does not require .ear files or a heavyweight container. Why, why, why??? I thought Spring framework chemotherapy had forced EJB into remission, but this seems much more virulent than I thought.
Bean validation (JSR 303) seems to be a way to ensure consistent data validation across tiers (through JSF in the presentation tier and JPA in the persistence tier). I can't help thinking this is just the Java version of XForms. XForms carries an XML document payload that is defined through a schema that can then be used to validate this instance data in any tier.
There's a lot of emphasis on the Glassfish server that I just can't understand. Again, it's probably critical for Sun to own an application server that isn't just Tomcat+Spring. It just isn't that relevant to the rest of the world. Glassfish has ambitions of being scalable, "from embedded to carrier-grade".
One corollary of a more modular Java that I deduced and that Sun acknowledged is that in the future, there will be just one Java. No more ME, SE and EE variants.
I next attended a rather boring and depressing session that was optimistically called "Tips and Tricks for Ajax Push and Comet Apps". This was conducted by Jean-François Arcand of Sun and Ted Goddard of ICEsoft Technologies. It was depressing because at the end of the day, there seems to be no satisfactory method to implement server push that will scale well and work on all browsers. The lecture was a tour of various unsatisfactory compromises. The three standard techniques (Polling, Ajax push (long polling) and HTTP Streaming) all have their drawbacks. I personally like HTTP Streaming with its chunked response (multiple as-and-when partial responses to a single request). However, this doesn't seem to work very well in practice because of the lack of a client-side API for reading such an input stream, and the tendency for proxies to cache responses instead of passing them on, incomplete though they may be.
My conclusion is that push is impossible with HTTP. We need to implement AMQP over TCP for true bidirectional messaging. It will take time, but it will happen within a decade. And then these problems (and their kludgy solutions) will seem laughable in retrospect.
The last session that I attended was "Spring Framework 3.0: New and Notable" by Rod Johnson himself. The hall was huge but absolutely packed.
Points in brief:
Spring 3.0 will use Java 5+. Anyone wishing to use Java 1.4 must remain with Spring 2.5. Three cheers for courage. Backward-compatibility is a two-edged sword, and I'm glad Spring has made the leap (no pun intended).
There is a new expression language (EL) that allows developers to navigate bean properties, invoke methods and allow construction of value objects. It also allows us to parameterise annotated code:
@Value("#{systemProperties.favoriteColor}")
private String favoriteColor;
where the term within "#{}" is in the EL.
There is an elegant implementation of REST based on Spring MVC (and what was unsaid was that it was not based on JAX-RS). The Spring MVC ViewResolver is a natural point to implement the various resource representations that REST provides a common interface to.
There are several MVC enhancements. @RequestHeader provides access to HTTP request headers. @CookieValue provides access to cookies. It's also possible to have application-specific annotations.
There is a new Java configuration mechanism. Annotations can now be placed in dedicated "configuration classes" rather than in POJOs themselves. In other words, these are XML files all over again, but in Java 5 syntax rather than using angle brackets. I like this, because I was uneasy about annotations. One of the major benefits of externalising configuration is the ability to decouple wiring from the application's own components and make it possible to substitute implementations without recompiling code. Annotations in code are a step backwards, from this viewpoint. Annotations in dedicated configuration classes are three-quarters of a step forward again. We still need a recompile, but only of the config classes.
Rod Johnson pointed out that previous versions of Spring had a rather ad hoc approach to the web side of an application, but that Spring 3.0 now features a consistent stack of components. The base is Spring MVC. Above this layer are Spring Web Flow, Spring Blaze DS (for Flex) and Spring JavaScript. At the top layer is Spring Faces (ugh!). Spring Blaze DS will make it very easy to build Flex apps with Spring. The diagram made no mention of Spring Portlet MVC, which is perhaps just as well. [The portlet specification is another monstrosity that continues to give organisations grief. As an "integration" technology, it belongs more in the problem space than in the solution space.]
The Spring Java config mechanism is type-safe and does not depend on string names. It therefore has more robust bean-to-bean dependencies. It allows inheritance of configuration. And it allows object creation using arbitrary method calls.
Johnson also introduced Spring Roo, the Domain-Driven Design tool and Ben Alex's brainchild. There is a major functional overlap between Roo and Grails, which Johnson did point out, but his logical flowchart to decide which one to use was a bit contrived, in my opinion. Roo and Grails are competitors, and the fact that they are uncomfortable co-components in the Spring portfolio does not make them part of a seamless product line with an implied "horses for courses" decision-making logic. To put it bluntly, if Roo had appeared a couple of years earlier, Grails would probably have been stillborn. The delay in Roo's release gave Grails its break, and now they're competing for developer mindshare. Well, may the best framework win.
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