IBM JRE是标准VM吗？

Question

I'm adding a JRE to Eclipse and I was given 3 options:

• Execution Environment Description
• Standard 1.1.x VM
• Standard VM

I was wondering if:

1. All JREs end up being VMs?
2. Does VM in this case mean JVM?
3. If the IBM JRE specifically was a Standard VM?
4. How do the 3 choices relate to each other?

Thanks

Answer 1

VM here refers to JVM. Any implementation of a JRE or JDK contains a Java Virtual Machine. The IBM implementation is, as far as I know, fully compatible with the Java specification, so you don't need to worry about compatibility. The distribution's name probably includes what version of the Java spec it's compatible with.

The options you were given allow you to choose between a JVM compatible with the 1.1.X version of Java, or one compatible with a later version (the latest is 7, but support for 6 is pretty wide as well). Unless you're maintaining some ancient legacy code, you'll want to add a "Standard VM" to your IDE.