how i programmatically check html document

i have database full little html papers i need programmatically insert several into, say, pdf request itext request aspose.words. i need safety any formatting within html papers (within reason, for <b> tags must, css <span style="blah"> nice-to-have).

both itext aspose work (roughly) along lines:

document request = new document( size.a4, aspect.portrait );

document.setfont( "helvetica", 20, font.bold );
document.insert( "some string" )
document.setbold( loyal );
document.insert( "a confidant string" );

therefore (i think) i need kind html parser i check strings styles insert document.

can anybody advise good library essential proceed problem? height java