Current File : //proc/309157/root/home/waritko/yacy/htroot/api/getpageinfo_p.java
// getpageinfo_p
// (C) 2011 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
// first published 11.11.2011 on http://yacy.net
//
// This is a part of YaCy, a peer-to-peer based web search engine
//
// $LastChangedDate$
// $LastChangedRevision$
// $LastChangedBy$
//
// LICENSE
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
import java.io.IOException;
import java.net.MalformedURLException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Locale;
import java.util.Set;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
import net.yacy.cora.document.id.AnchorURL;
import net.yacy.cora.document.id.DigestURL;
import net.yacy.cora.federate.yacy.CacheStrategy;
import net.yacy.cora.protocol.ClientIdentification;
import net.yacy.cora.protocol.RequestHeader;
import net.yacy.cora.util.ConcurrentLog;
import net.yacy.crawler.robots.RobotsTxtEntry;
import net.yacy.repository.Blacklist.BlacklistType;
import net.yacy.search.Switchboard;
import net.yacy.server.serverObjects;
import net.yacy.server.serverSwitch;
/**
* Remote resource analyzer
*/
public class getpageinfo_p {
/**
* <p>Scrape and parse a resource at a specified URL to provide some information, depending on the requested actions.</p>
*
* <p>
* Example API calls :
* <ul>
* <li>With the minimum required parameters : http://localhost:8090/api/getpageinfo_p.xml?url=http://yacy.net</li>
* <li>Only check the robots.txt policy and sitemap presence : http://localhost:8090/api/getpageinfo_p.xml?url=https://en.wikipedia.org/wiki/Main_Page&actions=robots</li>
* <li>Only check for an OAI Repository at CiteSeerX : http://localhost:8090/api/getpageinfo_p.xml?url=http://citeseerx.ist.psu.edu/oai2&actions=oai</li>
* </ul>
* </p>
*
*
* @param header
* servlet request header
* @param post
* request parameters. Supported keys :
* <ul>
* <li>url (required) : the URL of the resource to analyze. HTTP protocol is assumed if not present at the beginning of the URL.</li>
* <li>actions (optional) : a list of comma separated actions to perform (default to "title,robots"). Supported actions :
* <ul>
* <li>title : look for the resource title, description, language, icons, keywords, and links</li>
* <li>robots : check if crawling the resource is allowed by the eventual robots.txt policy file, and also if this file exposes sitemap(s) URLs.</li>
* <li>oai : send an "Identify" OAI-PMH request (http://www.openarchives.org/OAI/openarchivesprotocol.html#Identify)
* at the URL to check for a OAI-PMH response from an Open Archive Initiative Repository</li>
* </ul>
* </li>
* <li>agentName (optional) : the string identifying the agent used to fetch the resource. Example : "YaCy Internet (cautious)"</li>
* <li>maxLinks (optional integer value) : the maximum number of links, sitemap URLs or icons to return on 'title' action</li>
* <li>maxBytes (optional long integer value) : the maximum number of bytes to load and parse from the url on 'title' action</li>
* </ul>
* @param env
* server environment
* @return the servlet answer object
*/
public static serverObjects respond(final RequestHeader header, final serverObjects post, final serverSwitch env) {
final Switchboard sb = (Switchboard) env;
final serverObjects prop = new serverObjects();
// avoid UNRESOLVED PATTERN
prop.put("title", "");
prop.put("desc", "");
prop.put("lang", "");
prop.put("robots-allowed", "3"); //unknown
prop.put("robotsInfo", ""); //unknown
prop.put("sitemap", "");
prop.put("icons","0");
prop.put("sitelist", "");
prop.put("filter", ".*");
prop.put("oai", 0);
// default actions
String actions = "title,robots";
if (post != null && post.containsKey("url")) {
final int maxLinks = post.getInt("maxLinks", Integer.MAX_VALUE);
if (post.containsKey("actions"))
actions=post.get("actions");
String url=post.get("url");
if (url.toLowerCase(Locale.ROOT).startsWith("ftp://")) {
prop.put("robots-allowed", "1"); // ok to crawl
prop.put("robotsInfo", "ftp does not follow robots.txt");
prop.putXML("title", "FTP: " + url);
return prop;
} else if (!url.startsWith("http://") &&
!url.startsWith("https://") &&
!url.startsWith("ftp://") &&
!url.startsWith("smb://") &&
!url.startsWith("file://")) {
url = "http://" + url;
}
if (actions.indexOf("title",0) >= 0) {
DigestURL u = null;
try {
u = new DigestURL(url);
} catch (final MalformedURLException e) {
ConcurrentLog.logException(e);
}
net.yacy.document.Document scraper = null;
if (u != null) try {
ClientIdentification.Agent agent = ClientIdentification.getAgent(post.get("agentName", ClientIdentification.yacyInternetCrawlerAgentName));
if(post.containsKey("maxBytes")) {
/* A maxBytes limit is specified : let's try to parse only the amount of bytes given */
final long maxBytes = post.getLong("maxBytes", sb.loader.protocolMaxFileSize(u));
scraper = sb.loader.loadDocumentAsLimitedStream(u, CacheStrategy.IFEXIST, BlacklistType.CRAWLER, agent, maxLinks, maxBytes);
} else {
/* No maxBytes limit : apply regular parsing with default crawler limits.
* Eventual maxLinks limit will apply after loading and parsing the document. */
scraper = sb.loader.loadDocumentAsStream(u, CacheStrategy.IFEXIST, BlacklistType.CRAWLER, agent);
}
} catch (final IOException e) {
ConcurrentLog.logException(e);
// bad things are possible, i.e. that the Server responds with "403 Bad Behavior"
// that should not affect the robots.txt validity
}
if (scraper != null) {
// put the document title
prop.putXML("title", scraper.dc_title());
// put the icons that belong to the document
Set<DigestURL> iconURLs = scraper.getIcons().keySet();
long count = 0;
for (DigestURL iconURL : iconURLs) {
if(count >= maxLinks) {
break;
}
prop.putXML("icons_" + count + "_icon", iconURL.toNormalform(false));
prop.put("icons_" + count + "_eol", 1);
count++;
}
if(count > 0) {
prop.put("icons_" + (count - 1) + "_eol", 0);
}
prop.put("icons", count);
// put keywords
final Set<String> list = scraper.dc_subject();
count = 0;
for (final String element: list) {
if (!element.equals("")) {
prop.putXML("tags_"+count+"_tag", element);
count++;
}
}
prop.put("tags", count);
// put description
prop.putXML("desc", scraper.dc_description().length > 0 ? scraper.dc_description()[0] : "");
// put language
final Set<String> languages = scraper.getContentLanguages();
prop.putXML("lang", (languages == null || languages.size() == 0) ? "unknown" : languages.iterator().next());
// get links and put them into a semicolon-separated list
final LinkedHashSet<AnchorURL> uris = new LinkedHashSet<>();
uris.addAll(scraper.getAnchors());
final StringBuilder links = new StringBuilder(uris.size() * 80);
final StringBuilder filter = new StringBuilder(uris.size() * 40);
count = 0;
final Iterator<AnchorURL> urisIt = uris.iterator();
while (urisIt.hasNext()) {
AnchorURL uri = urisIt.next();
if (uri == null) continue;
if(count >= maxLinks) {
break;
}
links.append(';').append(uri.toNormalform(true));
filter.append('|').append(uri.getProtocol()).append("://").append(uri.getHost()).append(".*");
prop.putXML("links_" + count + "_link", uri.toNormalform(true));
count++;
}
prop.put("links", count);
prop.put("hasMoreLinks", scraper.isPartiallyParsed() || (count >= maxLinks && urisIt.hasNext()) ? "1" : "0");
prop.putXML("sitelist", links.length() > 0 ? links.substring(1) : "");
prop.putXML("filter", filter.length() > 0 ? filter.substring(1) : ".*");
}
}
if (actions.indexOf("robots",0) >= 0) {
try {
final DigestURL theURL = new DigestURL(url);
// determine if crawling of the current URL is allowed
ClientIdentification.Agent agent = ClientIdentification.getAgent(post.get("agentName", ClientIdentification.yacyInternetCrawlerAgentName));
RobotsTxtEntry robotsEntry = sb.robots.getEntry(theURL, agent);
prop.put("robots-allowed", robotsEntry == null ? 1 : robotsEntry.isDisallowed(theURL) ? 0 : 1);
prop.putHTML("robotsInfo", robotsEntry == null ? "" : robotsEntry.getInfo());
// get the sitemap URL(s) of the domain
final List<String> sitemaps = robotsEntry == null ? new ArrayList<String>(0) : robotsEntry.getSitemaps();
int count = 0;
for (String sitemap : sitemaps) {
if(count >= maxLinks) {
break;
}
prop.putXML("sitemaps_" + count + "_sitemap", sitemap);
count++;
}
prop.put("sitemaps", count);
} catch (final MalformedURLException e) {
ConcurrentLog.logException(e);
}
}
if (actions.indexOf("oai",0) >= 0) {
try {
final DigestURL theURL = new DigestURL(url
+ "?verb=Identify");
final String oairesult = checkOAI(theURL.toNormalform(false));
prop.put("oai", oairesult == "" ? 0 : 1);
if (oairesult != "") {
prop.putXML("title", oairesult);
}
} catch (final MalformedURLException e) {
}
}
}
// return rewrite properties
return prop;
}
/**
* @param url an OIA-PHM "Identify" request URL (http://www.openarchives.org/OAI/openarchivesprotocol.html#Identify). Must not be null.
* @return the OAI Repository name or an empty String when the response could not be parsed as an OAI-PMH response
*/
private static String checkOAI(final String url) {
final DocumentBuilderFactory factory = DocumentBuilderFactory
.newInstance();
try {
final DocumentBuilder builder = factory.newDocumentBuilder();
return parseXML(builder.parse(url));
} catch (final ParserConfigurationException ex) {
ConcurrentLog.logException(ex);
} catch (final SAXException ex) {
ConcurrentLog.logException(ex);
} catch (final IOException ex) {
ConcurrentLog.logException(ex);
}
return "";
}
/**
* Extract the OAI repository name from an OAI-PMH "Identify" response
* @param doc an XML document to parse. Must not be null.
* @return the repository name or an empty String when the XML document is not an OAI-PMH "Identify" response
*/
private static String parseXML(final Document doc) {
String repositoryName = null;
final NodeList items = doc.getDocumentElement().getElementsByTagName(
"Identify");
if (items.getLength() == 0) {
return "";
}
for (int i = 0, n = items.getLength(); i < n; ++i) {
if (!"Identify".equals(items.item(i).getNodeName()))
continue;
final NodeList currentNodeChildren = items.item(i).getChildNodes();
for (int j = 0, m = currentNodeChildren.getLength(); j < m; ++j) {
final Node currentNode = currentNodeChildren.item(j);
if ("repositoryName".equals(currentNode.getNodeName())) {
repositoryName = currentNode.getFirstChild().getNodeValue();
}
}
if (repositoryName == null) {
return "";
}
}
return repositoryName;
}
}
Mini Shell