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https://issues.apache.org/jira/browse/NUTCH-797?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12846865#action_12846865
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Jukka Zitting commented on NUTCH-797:
-------------------------------------
I guess we need to apply the same logic also to other Tika parsers that may
deal with relative URLs.
Since we in any case need this functionality in Tika, would it be useful for
Nutch if it was made available as a public utility class or method in
tika-core? It would be great if we could avoid duplicating the code in
different projects.
> parse-tika is not properly constructing URLs when the target begins with a "?"
> ------------------------------------------------------------------------------
>
> Key: NUTCH-797
> URL: https://issues.apache.org/jira/browse/NUTCH-797
> Project: Nutch
> Issue Type: Bug
> Components: parser
> Affects Versions: 1.1
> Environment: Win 7, Java(TM) SE Runtime Environment (build
> 1.6.0_16-b01)
> Also repro's on RHEL and java 1.4.2
> Reporter: Robert Hohman
> Priority: Minor
> Attachments: pureQueryUrl-2.patch, pureQueryUrl.patch
>
>
> This is my first bug and patch on nutch, so apologies if I have not provided
> enough detail.
> In crawling the page at
> http://careers3.accenture.com/Careers/ASPX/Search.aspx?co=0&sk=0 there are
> links in the page that look like this:
> <a href="?co=0&sk=0&p=2&pi=1">2</a></td><td><a
> href="?co=0&sk=0&p=3&pi=1">3</a>
> in org.apache.nutch.parse.tika.DOMContentUtils rev 916362 (trunk), as
> getOutlinks looks for links, it comes across this link, and constucts a new
> url with a base URL class built from
> "http://careers3.accenture.com/Careers/ASPX/Search.aspx?co=0&sk=0";, and a
> target of "?co=0&sk=0&p=2&pi=1"
> The URL class, per RFC 3986 at
> http://labs.apache.org/webarch/uri/rfc/rfc3986.html#relative-merge, defines
> how to merge these two, and per the RFC, the URL class merges these to:
> http://careers3.accenture.com/Careers/ASPX/?co=0&sk=0&p=2&pi=1
> because the RFC explicitly states that the rightmost url segment (the
> Search.aspx in this case) should be ripped off before combining.
> While this is compliant with the RFC, it means the URLs which are created for
> the next round of fetching are incorrect. Modern browsers seem to handle
> this case (I checked IE8 and Firefox 3.5), so I'm guessing this is an obscure
> exception or handling of what is a poorly formed url on accenture's part.
> I have fixed this by modifying DOMContentUtils to look for the case where a ?
> begins the target, and then pulling the rightmost component out of the base
> and inserting it into the target before the ?, so the target in this example
> becomes:
> Search.aspx?co=0&sk=0&p=2&pi=1
> The URL class then properly constructs the new url as:
> http://careers3.accenture.com/Careers/ASPX/Search.aspx?co=0&sk=0&p=2&pi=1
> If it is agreed that this solution works, I believe the other html parsers in
> nutch would need to be modified in a similar way.
> Can I get feedback on this proposed solution? Specifically I'm worried about
> unforeseen side effects.
> Much thanks
> Here is the patch info:
> Index:
> src/plugin/parse-tika/src/java/org/apache/nutch/parse/tika/DOMContentUtils.java
> ===================================================================
> ---
> src/plugin/parse-tika/src/java/org/apache/nutch/parse/tika/DOMContentUtils.java
> (revision 916362)
> +++
> src/plugin/parse-tika/src/java/org/apache/nutch/parse/tika/DOMContentUtils.java
> (working copy)
> @@ -299,6 +299,50 @@
> return false;
> }
>
> + private URL fixURL(URL base, String target) throws MalformedURLException
> + {
> + // handle params that are embedded into the base url - move them to
> target
> + // so URL class constructs the new url class properly
> + if (base.toString().indexOf(';') > 0)
> + return fixEmbeddedParams(base, target);
> +
> + // handle the case that there is a target that is a pure query.
> + // Strictly speaking this is a violation of RFC 2396 section 5.2.2 on
> how to assemble
> + // URLs but I've seen this in numerous places, for example at
> + // http://careers3.accenture.com/Careers/ASPX/Search.aspx?co=0&sk=0
> + // It has urls in the page of the form href="?co=0&sk=0&pg=1", and by
> default
> + // URL constructs the base+target combo as
> + // http://careers3.accenture.com/Careers/ASPX/?co=0&sk=0&pg=1,
> incorrectly
> + // dropping the Search.aspx target
> + //
> + // Browsers handle these just fine, they must have an exception
> similar to this
> + if (target.startsWith("?"))
> + {
> + return fixPureQueryTargets(base, target);
> + }
> +
> + return new URL(base, target);
> + }
> +
> + private URL fixPureQueryTargets(URL base, String target) throws
> MalformedURLException
> + {
> + if (!target.startsWith("?"))
> + return new URL(base, target);
> +
> + String basePath = base.getPath();
> + String baseRightMost="";
> + int baseRightMostIdx = basePath.lastIndexOf("/");
> + if (baseRightMostIdx != -1)
> + {
> + baseRightMost = basePath.substring(baseRightMostIdx+1);
> + }
> +
> + if (target.startsWith("?"))
> + target = baseRightMost+target;
> +
> + return new URL(base, target);
> + }
> +
> /**
> * Handles cases where the url param information is encoded into the base
> * url as opposed to the target.
> @@ -400,8 +444,7 @@
> if (target != null && !noFollow && !post)
> try {
>
> - URL url = (base.toString().indexOf(';') > 0) ?
> - fixEmbeddedParams(base, target) : new URL(base, target);
> + URL url = fixURL(base, target);
> outlinks.add(new Outlink(url.toString(),
> linkText.toString().trim()));
> } catch (MalformedURLException e) {
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