Artistic Style can format C, C++, and Java source code. Since I like it's default format, I generally run the command
astyle *.{c,h,cc,java}
in a directory. This copies all the original files to *.orig and formats everything!

Use astyle -h for the help page and style options.

• a2ps ftp://ftp.freebsd.org/pub/FreeBSD/ports/local-distfiles/obrien/a2ps-4.13.tar.gz

  Works with many source code formats, such as C, C++, Java, Lisp, yacc, sql, octave, html, perl, tcsh, sh, lex, mail, make, maple, matlab, modula, oberon, objc, ocaml, oracle, pascal, ada, awk, eiffel, verilog, vhdl, vrml, sed, haskel, fortran, tex, and a few others :).

  I usually use one of the following:

  • a2ps -r --columns=1 -T 4 -f 10 -C -s 2 --toc -o x.ps *.{whatever}
  • a2ps -R --columns=1 -T 4 -f 10 -C -s 2 --toc -o x.ps *.{whatever}
  • a2ps -T 4 -C -s 2 --toc -o x.ps *.{whatever}

• c2ps http://www.geocities.com/SiliconValley/Park/2055/
  Print C and C++ code. Has a nice format and includes per-page table of contents for functions. For C/C++, I like this better than a2ps.

  I usually use something like this:
  c2ps -t 4 -f 8 -d 0.3 -o x.ps *.{c,cc,h}

• doc++ ftp://ftp.sourceforge.net/pub/mirrors/metalab/Linux/apps/doctools/doc++-3.4.4.tar.gz

  A tool like Javadoc, but for C, C++, IDL, and Java! It generates both TeX and HTML.

  I have the HTML manual on-line.

• latexdoclet http://www.c2-tech.com/java/TexDoclet/

  Prints javadoc to LaTeX. Very handy.

  javadoc -private -classpath $X -docletpath doclet.jar -doclet com.c2_tech.doclets.TexDoclet $SRC/*.java -output $DST/x.tex

  I have found that for Letter paper, I need to modify the documentclass to use "letterpaper" and set "\topmargin -.4in".