What is the best approach to convert multipage html documentation to asciidoc?

Hello everyone. I am looking for a practical approach to convert multipage HTML documentation. For example Java specification. (Reason: Adding my code experiences and notes.)

Normally I do the following:

1. Download all pages with HTTrack Website Copier
2. Determine which part of the site be converted(All HTML pages similar content structure)
3. Gather all HTML documentation files to one folder
4. Convert all files to asciidoc with pandoc
5. Combine all asciidoc files into one text file using external software.

Any advice appreciated.
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