How to change default JRE for all Eclipse workspaces?

Question

I have one JRE in C:\\Program Files (x86)\\Java\\jre6 and that was the only one at the time I installed Eclipse. I have subsequently installed a complete JDK i

Answer 1

I navigated to:

Eclipse>Pref>Java>Installed JRE>Search...

2 of them popped up and I checked the latest one. Before I did this I also went to About>Check for Updates and updated it. I didn't have to reinstall any JRE or JDK either. I might have done it a while back, except it was with 1.6 not 1.4. Hope that helps!

Answer 2

The Installed JREs is used for what JREs to execute for your downstream Java projects and servers. As far as what JVM or JRE that is used to execute Eclipse process (workbench) itself that is controlled by your environment, history and eclipse.exe binary. So eclipse.exe itself decides what JRE Eclipse will execute itself with, not installed JREs preferences since those are not read until OSGi framework is up and running which is loaded after the JVM/JRE is picked.

So for new workspaces, Eclipse is going to use its currently executing JRE to populate the JRE prefs.

The best way I know how is to force eclipse.exe to use the JRE that you tell it via the -vm switch. So in your eclipse.ini do this:

-startup
plugins/org.eclipse.equinox.launcher_1.2.0.v20110502.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.win32.win32.x86_64_1.1.100.v20110502
-vm
/path/to/exactly/what/jre/you/want/as/default/javaw.exe
...

Answer 3

My answer will overlap with amphibient's while adding on to it.

Your JAVA_HOME variable is fine, but you also need to append the following to your Path variable :

;%JAVA_HOME%\bin

This will allow your applications in your Windows environment to access your JDK. You should also restart your computer once you've added these environment variables before checking out if they work. In my case, even logging out and then back in didn't work : I had to completely restart.

If you want to check if the environment variables are set correctly, you can open up a command prompt and type >echo %JAVA_HOME and >echo %Path% to see if those variables are working correctly. While snooping around for solutions, I have also run into people claiming that they need to add quotations marks (") around the environment variables to make them work correctly ("%JAVA_HOME%"\bin) if your JAVA_HOME path includes spaces. I thought that this was my case at first, but after doing a full restart my variables seemed to work correctly without quotation marks despite the spaces.

Answer 4

Finally got it: The way Eclipse picks up the JRE is using the system's PATH.

I did not have C:\home\SFTWR\jdk1.6.0_21\bin in the path at all before and I did have C:\Program Files (x86)\Java\jre6\bin. I had both JRE_HOME and JAVA_HOME set to C:\home\SFTWR\jdk1.6.0_21 but neither of those two mattered. I guess Eclipse did (something to the effect of) where java (or which on UNIX/Linux) to see where Java is in the path and took the JRE to which that java.exe belonged. In my case, despite all the configuration tweaks I had done (including eclipse.ini -vm option as suggested above), it remained stuck to what was in the path.

I removed the old JRE bin from the path, put the new one in, and it works for all workspaces.

Answer 5

I have faced with the same issue. The resolve: - Window-->Preferences-->Java-->Installed JREs-->Add... - Right click on your project-->Build Path-->Configure Build Path-->Add library-->JRE system library-->next-->WorkSpace Default JRE