I want to know is it possible to get the dimensions of componenst (like Doors) or there quantity from journal files? And also can we transfer the journal file to revit model again?
No, I do not believe that information such as door dimensions is included in the journal file.
Yes, you can in fact use a journal file generated by manually driving Revit and performing certain operations as a script to automatically drive Revit and repeat the exact same identical operations again.
This mechanism is used by the development team for unit testing purposes.
Here are some discussions on making use of this functionality: