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Microdata extraction from HTML in Java

2020-07-22 19:45发布

问题:

I really need help to extract Mircodata which is embedded in HTML5. My purpose is to get structured data from a webpage just like this tool of google: http://www.google.com/webmasters/tools/richsnippets. I have searched a lot but there is no possible solution.

Currently, I use the any23 library but I can’t find any documentation, just only javadocs which dont provide enough information for me.

I use any23's Microdata Extractor but getting stuck at the third parameter: "org.w3c.dom.Document in". I can't parse a HTML content to be a w3cDom. I have used JTidy as well as JSoup but the DOM objects in these library are not fixed with the Extractor constructor. In addition, I also doubt about the 2nd parameter of the Microdata Extractor.

I hope that anyone can help me to do with any23 or suggest another library can solve this extraction issues.

Edit: I found solution myself by using the same way as any23 command line tool did. Here is the snippet of code:

HTTPDocumentSource doc = new HTTPDocumentSource(DefaultHTTPClient.createInitializedHTTPClient(), value);
InputStream documentInputInputStream = doc.openInputStream();
TagSoupParser tagSoupParser = new TagSoupParser(documentInputInputStream, doc.getDocumentURI());
Document document = tagSoupParser.getDOM();
ByteArrayOutputStream byteArrayOutput = new ByteArrayOutputStream();
MicrodataParser.getMicrodataAsJSON(tagSoupParser.getDOM(),new PrintStream(byteArrayOutput));
String result = byteArrayOutput.toString("UTF-8");

These line of code only extract microdata from HTML and write them in JSON format. I tried to use MicrodataExtractor which can change the output format to others(Rdf, turtle, ...) but the input document seems to only accept XML format. It throws "Document didn't start" when I put in a HTML document.

If anyone found the way to use MicrodataExtractor, please leave the answer here. Thank you.

回答1:

xpath is generally the way to consume html or xml.

have a look at: How to read XML using XPath in Java