Is it possible and what tools could be used to parse an html document as a string or from a file and then to construct a DOM tree so that a developer can walk the tree throu
HTML Parser seems to support conversion from HTML to XML. Then you can build a DOM tree using the usual Java toolchain.
You can use TagSoup - it is a SAX Compliant parser that can clean malformed content such as HTML from generic web pages into well-formed XML.
This is <B>bold, <I>bold italic, </b>italic, </i>normal text
gets correctly rewritten as:
This is <b>bold, <i>bold italic, </i></b><i>italic, </i>normal text.
JTidy should let you do what you want.
Usage is fairly straight forward, but parsing is configurable. e.g.:
InputStream in = ...;
Tidy tidy = new Tidy();
// configure Tidy instance as required
...
...
Document doc = tidy.parseDOM(in, null);
Element root = doc.getDocumentElement();
The JavaDoc is hosted here.
You can take a look at NekoHTML, a Java library that performs a best effort cleaning and tag balancing in your document. It is an easy way to parse a malformed HTML (or a non-valid XML) file.
It is distributed under the Apache 2.0 license.
There are several open source tools to parse HTML from Java.
Check http://java-source.net/open-source/html-parsers
Also you can check answers to this question: Reading HTML file to DOM tree using Java It is almost the same...