Howto: Java 7(ea) & Eclipse 3.7.1 on Mac OS X

I recall that when Java 6 first came out, Mac OS X did not support it at first and it was only when Java 6 got full support by Apple that I decided to switch to a Mac. Now, years later Java 7 is out on Windows/Linux/etc and I have been feeling a bit cheated by Apple since they won’t provide Java 7 and have in fact decided to drop Java support in OS X in the future.

Happily, the OpenJdk project does have Java 7 for Mac OSX under development with an official build from Oracle available here.

In related news, Eclipse Indigo SR1 (v3.7.1) has just been released with full JDK1.7 support for Mac OS X. It is available here.

To get Eclipse 3.7.1 to work with Java 1.7 (EA) on Mac OS X do the following.

1) Install Java 7 but leave the more complete+stable Java 6 as the default Java on Mac OS X.

2) Install Eclipse and let it run under Java 6.

3) Start Eclipse, select Preferences,  Installed JREs, Execution Environments and click on “add”.

4) Select standard VM.

5) In the field JRE home, do not attempt to browse for the Java 7 directory as this will not work. Instead just paste the installation dir of the installed Java 7 package +/Content/Home (fx. “/Library/Java/JavaVirtualMachines/JDK 1.7.0 Developer Preview.jdk/Contents/Home”) into the JRE home text field and press return.

6) Fix the JRE name in the field below to something suitable like “JDK1.7” and click finish.

Now you should be able to create your Java 7 project in eclipse on your Mac OS X and you should be able to run/debug without problems…. Yes!

Portable Eclipse projects & goodbye to unbound classpath container (JRE) errors

It is nice to have Eclipse projects under source control but unless you setup your project correctly you will have a high risk of getting JRE errors like “unbound classpath container” when you share your project with other developers.

• For new projects make sure to select “Execution Environment JRE” when you create your projects – do not select project specific JRE or default JRE!
• For existing projects select package view, right click on JRE system library, select “Execution Environment” and the appropriate environment.  F.x. JavaSE-1.6