I have the existing codebase which runs on java6, but the current requirement is to upgrade the Java from java6 to java 7, Can anyone please let me know the steps, how can i upgrade it using eclipse(because i am using eclipse as IDE)?.
Upgrading code requires almost nothing, as Java 7 is backwards compatible with Java 6 except for a few things, mostly behavioral and in the standard library. And as said here, it should mostly just work:
What do I need to do?
Option 1 – “Just run”
Upgrading your eclipse project has been asked and answered several times, like here.
Related
I have a doubt about java upgrading
I have applications running in java 6, for example.
And I wanto to upgrade my java to a 7 or 8
My doubt is: What is the best way to upgrade mi current java version?
Or how can I do it?
This applications currently are productive, so this means I has to upgrade the java version witouth affectate it.
I'm very confused about this, hope you can help me
There's only one way to do it:
Upgrade the JVM
Recompile the code and fix any errors that the JVM complains about.
Regression test the code running under the new JVM and make sure the functionality is unchanged.
Take the opportunity to see if there are any advantages to adding new features (e.g. java.time package, lambdas, java.util.function package, etc.)
No one should be running on any JVM other than 8 or 9. JDKs older than 8 have passed the end of their support lives. They are not getting any more security patches.
You are making the excuse that everyone tries when faced with currency issues: "The code is working fine. Why change it?"
Unfortunately there's a price to falling behind.
I'd advise you to upgrade as soon as possible. Stop the excuses.
JDK 9 is the current version. Current or current-1 is usually acceptable; current-3 is not.
this is a follow up question about previously one Corda running on Java 9
We appreciate you have already started to work on Java 9 support. Are you able to tell us an estimated month for this completion? I believe all major organisation also have a red flag on all Java 8 application and require a plan for upgrade. Regarding bundling JRE into Corda, is this only going to happen for the Enterprise version? If so, for the open source version would you continue to support the latest version of Java?
Thanks in advance
Javier
We aim to be on the latest release of Java to take advantage of its latest capabilities. However, we don't have a specific timeframe for Java 9 support at this time. We will communicate this in the near future via Corda.net.
Since the release of Java 8, I found myself slowly becoming dependent on Java 8-specific features (ex. lambda statements) on a library project that I have just started.
I have seen many other projects which, to this day, still build against Java 7, or even Java 6, causing me to second-guess myself.
Is it a good idea to immediately start building against the newest version of Java, or should I still use older versions?
Note that unlike those other projects that have started back when Java 6/7 was the newest version, mine was started recently when Java 8 is the newest.
There are two reasons I can think of that would require staying with a pre-Java 8 JVM:
You are writing a library that is being used by a large group of people outside your organization who are still stuck on a pre-Java 8 JVM. If you use the latest and greatest JVM, they won't be able to use your product anymore.
You are dependent on a 3rd party library that has not upgraded to Java 8 and breaks on Java 8.
Since you mentioned this is a new project, #1 is unlikely. Even if you plan on having external users, if it's a new project, requiring the latest version of the JVM isn't really an issue.
Number 2 is also getting more and more unlikely as the more popular 3rd party libraries have released updates to work on Java 8. Even the few stragglers are usually OK working on Java 8. For example I use an ancient version of hibernate with Java 8. I just don't use any Java 8 features in any mapped fields/entities.
Java 8 denotes a major change to the language since Java 5 (or perhaps its inception). If you are targeting specifically the changed language parts (which I guess you claim) then making it usable only by Java 8+ runtime makes sense.
When Java 5 occurred 10 years ago and you wanted to use all the new features introduced at the time (e.g. foreach statement, Enums etc.) into your own library development, what would you have done? I believe you would have made your library require Java 5 at the minimum. If you agree with that, then that (sound) logic applies consistently to your present situation as well.
For server side application, possibly a version or two prior to the current version as suggested by EJP.
On the client side however, I don't see any point in trying to support older Java versions. The JRE has been auto-updating since at least Java 6. It has gotten to the point where Java Web Start launched applications cannot specify an earlier than current JRE. Or rather, it can specify any JRE it chooses in the launch file, but that will be ignored in favor of the latest version installed on the user's computer.
We are planning to upgrade our Tomcat from 4.1.31.
Our's is an Axis 1.4 application where we have our web services.
Request you to suggest the latest stable version of Tomcat 5 or Tomcat 6 suitable for our application. And the things to consider while upgrading.
Will the existing 1.4 Java code base works smoothly on Tomcat 5 or 6?
And going further we may write the code in JDK 1.5 as well. So, having Java 1.4 code and Java 1.5 code together, will create any problems?
Kindly suggest.
Please share your upgradation experiences.
Thank You :)
Tomcat 6.0.26 is the latest stable release.
It requires JRE 5.0 or later, so if you are truly stuck on 1.4, you'll need to download the latest 5.5 release, which requires a compatability package to run on 1.4.
My advice: bite the bullet and make the necessary changes for your application to function on 1.6. It is only going to get more and more painful to upgrade (and to continue to code in 1.4) as time goes on.
Go to Java (1.)6; it really makes doing web services like yours easier and it's really widely available now.
If you are going to upgrade I would recommend first doing some tests with java 6 + the existing codebases. If that seems to work, go to Tomcat 6.
Perhaps also upgrade some Axis libraries while you're at it, or leave it as is if it still works.
In my experience you can get to trouble by migrating to Java 5 (and thus 6), especially with XML. My memory has something like a class name clash between Java 5 and an old version of Xerces, but I could be mistaken.
We've been developing a windows based application using Java for a while now, but NOW we want to make a mac port and have to reverse of code from Java 6 and Java 5. Is there any easy way to do this rather than re-coding Java 6 specific code? We'd like to keep our code up to date.
There are a couple of libraries out there which can help you. Unfortunately I haven't tried them myself, because I've never run into such a situation.
Retroweaver
Retrotransaltor
backport-jsr166
See here:
http://en.wikipedia.org/wiki/Comparison_of_backporting_tools
I tried retrotranslator from 1.6 to 1.4.2 and it works pretty well!
Apple released Java 6 on the latest version of OS X. What features are you using specifically from Java6 that aren't in java5?
In my experience this is so easy that the whining takes more time than the doing. There are very few things in 1.6 that can't be backported with a minute or so (literally) worth of work. How many compile errors are you seeing when you try it with 1.5, and what for?
Keep in mind that there are readily available, API compatible, low-footprint backports for the few things that are useful in 1.6 (SwingWorker).
Do you know how much you would have to rewrite if you just went back to Java 5? If you changes the JDK setting in your IDE and try to recompile it should give you a pretty good idea on how big the changes would actually be. For most developers, Java 6 didn't really offer too much in the way of new features/APIs but I guess it's possible your project depends heavily on something that was added.
There is also Java 8 for Mac OS X. New versions of Java would be compatible, like Java 8 is compatible with Java 5 Code, so Java 6 code is compatible too.
You might be able to backport the additional libraries from Java 6 to Java 5, but I imagine it would be rather more trouble that it's worth. Intel Macs with 64-bit processors (so not the original Intel Mac Mini) running Leopard have Java 6, so perhaps you could just target them?