What version of Java is running in Eclipse?

Question

How do I know what version of Java is being run in Eclipse?

Is there a way to write code to find out?

Is "JRE System Library [JavaSE-1.6]" in "Package Explorer" the right version?

Answer 1

String runtimeVersion = System.getProperty("java.runtime.version");

should return you a string along the lines of:

1.5.0_01-b08

That's the version of Java that Eclipse is using to run your code which is not necessarily the same version that's being used to run Eclipse itself.

Answer 2

The one the eclipse run in is the default java installed in the system (unless set specifically in the eclipse.ini file, use the -vm option). You can of course add more Java runtimes and use them for your projects

The string you've written is the right one, but it is specific to your environment. If you want to know the exact update then run the following code:

public class JavaVersion {
  public static void main(String[] args) {
    System.out.println(System.getProperty("java.runtime.version"));
  }
}

Answer 3

Don't about the code but you can figure it out like this way :

Go into the 'window' tab then preferences->java->Installed JREs. You can add your own JRE(1.7 or 1.5 etc) also.

For changing the compliance level window->preferences->java->compiler. C Change the compliance level.

Answer 4

Eclipse uses the default Java on the system to run itself. This can also be changed in the eclipse.ini file in your eclipse install folder.

To find out the version of java that your eclipse project is using, see Project->properties->build path->Libraries tab and see the JRE system library thats being used. You can also check it out at Window->Preferences->Java->Installed JREs. This is a list of all JREs that eclipse knows about

To find out using code, use the System.getProperty(...) method. See http://java.sun.com/j2se/1.5.0/docs/api/java/lang/System.html#getProperties() for supported properties.