You can use regular expressions (java.util.regex package) if the tags are easy to identify in your documents.
If html used in a complex way in your documents (e.g. if they might have invalid html like not having some closing tags), then you should use a library to parse the html document. I recommend you to use an
html parser. They are easy to use.
And if you dont want to use an additional library in your project, you can try using
Swing HTML Parser.
Linear Mode
