Programming Java 8 in Eclipse

Question

The development of Eclipse support for Java 8 is ongoing in a branch (http://wiki.eclipse.org/JDT_Core/Java8).

To try out the current Eclipse support for Java 8, I did the following:

1. I installed a build of JDK 8 (This step is optional).
2. I checked out branch BETA_JAVA8 of git://git.eclipse.org/gitroot/jdt/eclipse.jdt.core.git.
3. I imported the checked out projects in an instance of Eclipse Juno SR1 (Build ID: 20120920-0800).
4. I ran a new instance of Eclipse from my running Eclipse.

To use the new syntax available in Java 8, Eclipse said that I have to set the compliance level of my code to 1.8. To set the compliance level, I have to set the execution environment to JavaSE-1.8. This execution environment was not available at Windows -> Preferences -> Java -> Installed JREs -> Execution Environments.

How can I set the execution environment to JavaSE-1.8?

The following summarizes some of my attempts to install the execution environment:

1. I followed the wiki instructions looking for a description of JavaSE-1.8 at the update site http://download.eclipse.org/eclipse/updates/4.2. But, the definition of the execution environment wasn't there.
2. I looked for the JavaSE-1.8 profile in the git repository of rt.equinox.framework, but, it wasn't there.

Answer 1

I just went to the Eclipse Marketplace from inside of Eclipse (Help/Eclipse Marketplace...) and installed the "Java 8 support for Eclipse Kepler SR2", and the new "JavaSE-1.8" execution environment showed up automatically. I had previously installed Java 8 and added it as a 'Installed JREs' entry. No need to mess with property files.

Answer 2

Think you just have to change the 'settings' directly in the 'preference file' : org.eclipse.jdt.core.prefs .

e.g. org.eclipse.jdt.core.compiler.compliance=1.8