what is meant by Java 2 SDK tools ? Is tools something different from classes ?
Note that the classes which implement the Java 2 SDK tools are in a separate archive from the bootstrap classes
What about core java classes. It does not say anything about core java classes and packages. Are core java classes known as extension classes ? If not, then how are these classes found ?
In general, you only have to specify the location of user classes. Bootstrap classes and extension classes are found "automatically".
I understand that they are included with java installation, but how do compiler finds these classes ? How is classpath set for these packages ? Can I see them in environment variables ? If not, then how is classpath set ?
They are included with the Java installation, and the compiler knows where they are.
So, is rt.jar set in some classpath ? When compiler starts looking for some classes it will look in environment variables. So is this rt.jar set in any environment variable ? If compiler does not find classpath in environment variables, does it look for anywhere else ? If no, then how is rt.jar set to be made available to compiler ?
They line inside a file called rt.jar (I think) and the compiler is programmed to look there