Hi all,

I am confused with what really "compiler compliance level" means.

I am trying to make a "web project" in myeclipse 7.5 with the default compiler compliance level of 1.6 and the default jdk6 that comes with it. However, it gives me "Incompatible Java Compliance Level" error, if i follow the steps as listed below:

1- Open myeclipse ide in my default workspace (d:\__nece)
2- File -> New -> Web Project
3- Enter name of project as "e6"
4- Select J2EE specification level to be "Java EE 5.0"
5- Click "Finish"

My installation details are as follows:

Code:

*** Date: Sunday, August 2, 2009 7:01:42 PM AST ** System properties: OS=WindowsXP OS version=5.1.0 Java version=1.6.0_13 *** MyEclipse details: MyEclipse Enterprise Workbench Version: 7.5 Build id: 7.5-20090609 *** Eclipse details: MyEclipse Enterprise Workbench Version: 7.5 Build id: 7.5-20090609 Eclipse Plug-in Development Environment Version: 3.4.2.R342_v20090122-7T7U1E9imVKz-A8Vz-p_jRS Build id: M20080703-0800 Eclipse Platform Version: 3.4.2.R342_v20090122-9I96EiWElHi8lheoJKJIvhM3JfVsYbRrgVIWL Build id: M20090211-1700 Eclipse Graphical Editing Framework GEF Version: 3.4.2.v20090218-1145-67728084A56B4I233613552 Build id: 200809101400 Eclipse RCP Version: 3.4.200.R342_v20090122-989JESTEbig-SVaL8UJHcYBr4A63 Build id: M20090211-1700 Eclipse Java Development Tools Version: 3.4.2.r342_v20081217-7o7tEAoEEDWEm5HTrKn-svO4BbDI Build id: M20090211-1700 Eclipse startup command=-os win32 -ws win32 -arch x86 -showsplash -launcher C:\Program Files\Genuitec\MyEclipse 7.5\myeclipse.exe -name Myeclipse --launcher.library C:\Program Files\Genuitec\MyEclipse 7.5\../Common\plugins\org.eclipse.equinox.launcher.win32.win32.x86_1.0.101.R34x_v20080731\eclipse_1115.dll -startup C:\Program Files\Genuitec\MyEclipse 7.5\../Common\plugins\org.eclipse.equinox.launcher_1.0.101.R34x_v20081125.jar -clean -configuration configuration -clean -vm C:\Program Files\Genuitec\Common\binary\com.sun.java.jdk.win32.x86_1.6.0.013\jre\bin\client\jvm.dll

mnsharif,

Are you referring to the below screenshot? It is not an error but a warning. If you right click on your project and go to Properties > Java Compiler. It will show you the compiler compliance level is 1.5 because you have selected the J2EE Specification Level as Java EE5.0.
You can set your Compiler's JDK compliance here - From MyEclipse menu options click on Window > Preferences > Java > Compiler.

Hey Joy,

Thanks for your response.

Quote:

Are you referring to the below screenshot?

Yes, exactly. But the fact that it is a warning only, does this mean that i can configure my application to us J2EE5.0 specification level and still keep the compiler compliance level to be 1.6?

Quote:

It will show you the compiler compliance level is 1.5 because you...

No, it does not because i clicked on "No" when it asked me for "Do you want to use a custom setting for your project?" I want to use 1.6 as compliance level, so i clicked on "No" and therefore, it shows me compliance level as "1.6" (which is default for the workspace).

Quote:

... because you have selected the J2EE Specification Level as Java EE5.0.

Correct me if i am wrong, this means that if i select J2EE specification level to be EE5.0, i can not set the compiler compliance level to 1.6? Doesn't this mean that practically one can not have an EE application with compliance level of 1.6? This sounds un-natural to me. Is there an explanation for it that i am not aware of? Or am i just hallucinating?

regards,
--mnsharif

mnsharif,

By setting the compliance level to 1.6, Eclipse will allow you to use API/methods that were introduced in 1.6 in your project, this code will only work if executed with a 1.6 VM, you would likely get a NoSuchMethodError if you run it with a 1.5 series VM or it is possible that you get the class version error and the classes will not even load.

Now when it comes to Java EE 5.0, the minimum requirement for a Java EE 5.0 server is a Java 1.5 VM. If you do run your server - say Tomcat with a 1.5 VM and deploy your 1.6 compliant application on it, you could run into the issues described above. This is why we present you with a warning dialog that allows you to change the compliance level. There is nothing wrong with choosing 1.6 as a compliance level, you should ensure you run your server with a 1.6 JDK as well to avoid problems.

Hope this helps.

Ahan, that's cool.

I will keep my compliance level to 1.6 by ignoring this warning, and will offcourse ensure that i use JDK6 for both development and deployment.



I think, improving the error message in this case would be a great help. Currently it states:

Incompatible Java Compliance Level
Compiler compliance level of project e6 should be 5.0. Your current workspace default is 6.0. Do you want to use a custom setting for your project?
Yes No Cancel

I think, the following alternate would do a better job of explaining the issue when the selected compliance level is _higher_ than the one required by the specifications.

Java Compliance Level Mismatch
Compiler compliance level of project e6 should be 5.0 or higher. Your current workspace default is 6.0. Do you want to use a custom setting for your project?
Yes No Cancel


And a similar message when the selected compliance level is _lower_ than the one required by the specifications.

Incompatible Java Compliance Level
Compiler compliance level of project e6 should be 5.0 or higher. Your current workspace default is 1.3. <A sentence describing the NoSuchMethodError/class version/loading issue in a user friendly manner>. Do you want to use a custom setting for your project?
Yes No Cancel

Thanks for your help once again, guys!

regards,
--mnsharif

mnsharif,
Thank you for your feedback. I shall make a note of your request.

It's years later and the same annoying, confusing behavior still occurs on MyEclipse 9.1.

We're using version 6 with EE 5. I don't even have a 1.5 jdk on my dev box. I just created a Web Project several times. I select File > New > Web Project. Then, I enter a name, note that the default Java EE 5.0 is still selected, and click Finish. It pops the Incompatible Java Compliance Level box:

Compiler compliance ... should be 5.0. Your ... default is 6.0. Do you want to use a custom setting for your project?

If I click No, the box goes away and my project is created. If I display its properties, the compliance level is set to 1.5, the Use default... box is checked, the shadowed values show 1.5, and there's an alert message about my lack of a 1.5 jdk.

If I click Yes, I get the same results.

There is also a link "Open workspace compiler settings". If I click the link, it shows my workspace settings including (gasp!) compiler compliance 1.6. When I click OK there, that window and the popup both disappear and my project is created. With a compliance level of 1.5. Of course.

The message in the box should be changed. It should be possible to create a Web Project (or other EE project) with the workspace default compliance level. Just in case a user wants a different compliance level for EE projects, there should be a workspace setting for the EE compliance level.

I looked at the Web Project tutorial just to see if this issue was mentioned there. (It isn't.) The tutorial should be updated to show more current pictures, etc.

vgriffin ,

Please refer - http://myeclipseide.com/index.php?name=PNphpBB2&file=viewtopic&t=28362&highlight=

This is going to be fixed in ME 10 release.