Feeds

Time for genuine 'write-once, run-anywhere' Java

Oracle and BEA: a new hope?

Build a business case: developing custom apps

One of the big selling points of Java has been its "write once, run anywhere" capabilities. Of course, in practice, this has always been "write once, test everywhere" you intend to deploy your chosen application.

With the planned purchase of BEA Systems by Oracle, I got to thinking about what this meant for the "write once, run anywhere" mantra in relation to application servers.

My thoughts were partly spurred by my need to port a large server application to IBM's WebSphere and Oracle's Application Server from BEA's WebLogic. This left me thinking about the practicalities involved in porting Java, and looking for areas where an ironing out of inconsistencies between Java containers would have a beneficial effect.

As I looked deeper at the challenges the companies would face, it became clear that in many cases the problem with Java portability springs from a combination of developer ignorance and specification omissions - or at least limitations.

When it comes to Java across different Virtual Machines, there are at least two gotchas you should be wary of. The first relates to the type of JVM available. For example, we had an application running on one hardware platform using a 64-bit JVM and all was fine. In moving to a new platform, there was only a 32-bit JVM available. On this platform the application suddenly started experiencing out of memory exceptions. In a similar vain, I know of a colleague who had a working system on a 32-bit JVM but when moving to a 64-bit JVM found that it required more memory.

The second gotcha relates to non-Java standard classes. For example, a little while ago I encountered a developer who had directly referenced the sun.security.provider.X509Factory class; this was only found when the code was run on an IBM JVM and this class was, of course, missing. Perhaps the developer should not have used this class - but nothing actually stopped him from doing so.

Next, there are application-server specific issues. I refer, of course, to those parts of a server-side system that are not specified by Java EE but are needed to correctly deploy an application to the application server. These are application-server specific deployment descriptors (such as weblogic.xml or orion.xml). Each of these files has its own format, which may vary widely (for example WebSphere uses an .XMI format). However, it goes further than that, as in some cases defaults can be assumed and on other application servers no default is provided - or an alternative default is used.

Bridging the IT gap between rising business demands and ageing tools

More from The Register

next story
NO MORE ALL CAPS and other pleasures of Visual Studio 14
Unpicking a packed preview that breaks down ASP.NET
Cheer up, Nokia fans. It can start making mobes again in 18 months
The real winner of the Nokia sale is *drumroll* ... Nokia
Mozilla fixes CRITICAL security holes in Firefox, urges v31 upgrade
Misc memory hazards 'could be exploited' - and guess what, one's a Javascript vuln
Put down that Oracle database patch: It could cost $23,000 per CPU
On-by-default INMEMORY tech a boon for developers ... as long as they can afford it
Google shows off new Chrome OS look
Athena springs full-grown from Chromium project's head
Apple: We'll unleash OS X Yosemite beta on the MASSES on 24 July
Starting today, regular fanbois will be guinea pigs, it tells Reg
HIDDEN packet sniffer spy tech in MILLIONS of iPhones, iPads – expert
Don't panic though – Apple's backdoor is not wide open to all, guru tells us
prev story

Whitepapers

Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.