how to parse html with nutch and index specific ta

问题:

i have installed nutch and solr for crawling a website and search in it; as you know we can index meta tags of webpages into solr with parse meta tags plugin of nutch.(http://wiki.apache.org/nutch/IndexMetatags) now i want to know is there any way to crawl another html tag to solr that isn't meta?(plugin or anyway) like this:

<div id=something>
      me specific tag
</div>

indeed i want to add a field to solr (something) that have value of "me specific tag" in this page.

any idea?

回答1:

I made my own plugin for something similar you want to. The config file for mapping NutchDocument to SolrDocument is in $NUTCH_HOME/conf/solrindex-mapping.xml. Here you can add your own tags. But still you have to fill your own tags somewhere.

Here are some tips to plugin:

• read http://wiki.apache.org/nutch/WritingPluginExample, here you can find how to make your plugin very simply
• in your plugin extend the ParseFilter and IndexingFilter.
• in YourParseFilter you can use NodeWalker to find your specific div

• your parsed informations put into page metadata like this

  page.putToMetadata(new Utf8("yourKEY"), ByteBuffer.wrap(YourByteArrayParsedFromMetaData));

• in YourIndexingFilter add the metadata from page (page.getMetadata) to NutchDocument

  doc.add("your_specific_tag", value);

• most important!!!!!

• put your_specific_tag to fileds of:

  • Solr config file schema.xml (and restart Solr)

  field name="your_specific_tag" type="string" stored="true" indexed="true"

  • Nutch config file schema.xml (don't know if it is realy neccessary)
  • Nutch config file solrindex-mapping.xml

  field dest="your_specific_tag" source="your_specific_tag"

回答2:

u have to just try http://lifelongprogrammer.blogspot.in/2013/08/nutch2-crawl-and-index-extra-tag.html the tutorial said img tag how to get and what all are steps are there mention...

回答3:

You can use one of these custom plugins to parse xml files based on xpath (or css selectors):

• https://github.com/BayanGroup/nutch-custom-search
• http://www.atlantbh.com/precise-data-extraction-with-apache-nutch/

回答4:

You may want to check Nutch Plugin which should allow you to extract an element from a web page.