How to generate a PDF from JavaDoc (including overview and package summaries)

Nailed it. After trying all the possible tools to generate straight from the source, I returned to HTMLDOC. It is not JavaDoc-aware, but it is so well built that a few tweaks are enough to make it generate a pretty usable PDF.

Here goes a step-by-step description of how I did it:

1. Download the software on the releases page;

2. Generate your traditional HTML docs in your preferred way (Ant, Maven, command-line javadoc - your choice);

3. The GUI is nice, but adding all files manually can be cumbersome, so just create a .book file with Document Type set to "Web Page", add one of the HTML files from your generated javadoc's root folder (e.g., overview-summary.html, anyone will do, it's just for reference on step 5). On the Output tab select the PDF format and set a name for it, and add other options to your heart's content (logos, colors, lots of cool stuff here). Save this project (say, myjavadocpdf.book) and close the GUI

4. Generate a list of all HTML files in your javadoc. I did it with Cygwin's find command (my DOS/cmd shell days are long over), but you can do anything you want, as long as you get a file list. In my case a find . | grep html$ | sort -r > files.txt did the trick; For Windows users, dir /s/b *.html > files.txt should do the same (but keep in mind you may have to replace \s with /s if they appear like so on the next step).

5. Open the .book file generated on step 3 in your favorite pure text editor (as a programmer you should have strong opinions on that, so will keep my opinions to myself - NOT ;-) ) and append the list generated on step 4 to this .book file (it keeps the list of files at the end, making life really easy). Don't forget to fix the relative paths, if needed with a global search/replace (that's why you needed at least one file added on step 3 - to see which file path pattern htmldoc expects);

6. Now you should sort the files in a convenient order. I put my overview first, then package descriptions and each class, then the full index, and everything else at the end. Remember that any file you delete will become an external (hence broken) link, so choose wisely;

7. Save your .book file and re-open it on HTMLDOC. Voila: all files added and sorted. Click on generate. That's it!

You may want to fiddle with images (hint: use HTML width/height, not style/css). In the end, the resulting file is surprisingly good: nice looking and fully navigable for internal and external links. Impressive when you consider that the tool is not Java(Doc) aware at all...

EDIT: software is now free from original author; updated links, thank you @mohammed

According to the Sun JavaDoc FAQ, there's a couple of options -- mostly free, with one or two commercial offerings as well. Check it out at http://java.sun.com/j2se/javadoc/faq/index.html#print.