// opensearchdescriptionReader.java
// (C) 2008 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
// first published 11.03.2008 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
package net.yacy.document.parser.xml;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.HashSet;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import net.yacy.cora.protocol.ClientIdentification;
import net.yacy.cora.protocol.http.HTTPClient;
import net.yacy.cora.util.ConcurrentLog;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
/*
* reads opensearchdescription xml document and provides the parsed search url
* templates via get methodes as well as all other tags by getItem(tagname)
*/
public class opensearchdescriptionReader extends DefaultHandler {
//private static final String recordTag = "OpenSearchDescription";
private static final String[] tagsDef = new String[]{
"ShortName",
"LongName",
// "Image",
"Language",
"OutputEncoding",
"InputEncoding",
"AdultContent",
"Description",
"Url",
"Developer",
"Query",
"Tags",
"Contact",
"Attribution",
"SyndicationRight"
};
/*
<?xml version="1.0" encoding="UTF-8"?>
<OpenSearchDescription xmlns="http://a9.com/-/spec/opensearch/1.1/">
<ShortName>YaCy/#[clientname]#</ShortName>
<LongName>YaCy.net - #[SearchPageGreeting]#</LongName>
<Image type="image/gif">http://#[thisaddress]#/env/grafics/yacy.gif</Image>
<Language>en-us</Language>
<OutputEncoding>UTF-8</OutputEncoding>
<InputEncoding>UTF-8</InputEncoding>
<AdultContent>true</AdultContent>
<Description>YaCy is an open-source GPL-licensed software that can be used for stand-alone search engine installations or as a client for a multi-user P2P-based web indexing cluster. This is the access to peer '#[clientname]#'.</Description>
<Url type="application/rss+xml" method="GET" template="http://#[thisaddress]#/yacysearch.rss?query={searchTerms}&Enter=Search" />
<Developer>See http://developer.berlios.de/projects/yacy/</Developer>
<Query role="example" searchTerms="yacy" />
<Tags>YaCy P2P Web Search</Tags>
<Contact>See http://#[thisaddress]#/ViewProfile.html?hash=localhash</Contact>
<Attribution>YaCy Software © 2004-2007 by Michael Christen et al., YaCy.net; Content: ask peer owner</Attribution>
<SyndicationRight>open</SyndicationRight>
</OpenSearchDescription>
*/
private static final HashSet<String> tags = new HashSet<String>();
static {
for (final String element : tagsDef) {
tags.add(element);
}
}
// class variables
private final StringBuilder buffer;
private boolean parsingDescription, parsingTextValue;
private final HashMap<String, String> items; // Opensearchdescription Item map
private String rssurl, atomurl; // search url templates
private ClientIdentification.Agent agent;
public opensearchdescriptionReader() {
this.items = new HashMap<String, String>();
this.buffer = new StringBuilder();
this.parsingDescription = false;
this.parsingTextValue = false;
this.rssurl = null;
this.atomurl = null;
this.agent = ClientIdentification.yacyInternetCrawlerAgent;
}
private static final ThreadLocal<SAXParser> tlSax = new ThreadLocal<SAXParser>();
private static SAXParser getParser() throws SAXException {
SAXParser parser = tlSax.get();
if (parser == null) {
try {
parser = SAXParserFactory.newInstance().newSAXParser();
} catch (final ParserConfigurationException e) {
throw new SAXException(e.getMessage(), e);
}
tlSax.set(parser);
}
return parser;
}
public opensearchdescriptionReader(final String path) {
this();
try {
final SAXParser saxParser = getParser();
saxParser.parse(path, this);
} catch (final Exception e) {
ConcurrentLog.logException(e);
}
}
public opensearchdescriptionReader(final InputStream stream) {
this();
try {
final SAXParser saxParser = getParser();
saxParser.parse(stream, this);
} catch (final Exception e) {
ConcurrentLog.logException(e);
}
}
public opensearchdescriptionReader(final String path, final ClientIdentification.Agent agent) {
this();
this.agent = agent;
try {
HTTPClient www = new HTTPClient(agent);
www.GET(path, false);
final SAXParser saxParser = getParser();
saxParser.parse(www.getContentstream(), this);
www.finish();
} catch (final Exception e) {
ConcurrentLog.logException(e);
}
}
public boolean read(String path) {
this.items.clear();
this.buffer.setLength(0);
this.parsingDescription = false;
this.parsingTextValue = false;
this.rssurl = null;
this.atomurl = null;
try {
HTTPClient www = new HTTPClient(this.agent);
www.GET(path, false);
final SAXParser saxParser = getParser();
try {
saxParser.parse(www.getContentstream(), this);
} catch (final SAXException se) {
www.finish();
return false;
} catch (final IOException ioe) {
www.finish();
return false;
}
www.finish();
return true;
} catch (final Exception e) {
ConcurrentLog.warn("opensearchdescriptionReader", "parse exception: " + e);
return false;
}
}
@Override
public void startElement(final String uri, final String name, final String tag, final Attributes atts) throws SAXException {
if ("OpenSearchDescription".equals(tag)) {
this.parsingDescription = true;
} else if (this.parsingDescription) {
if ("Url".equals(tag)) {
this.parsingTextValue = false;
String type = atts.getValue("type");
if ("application/rss+xml".equals(type)) {
rssurl = atts.getValue("template");
} else if ("application/atom+xml".equals(type)) {
atomurl = atts.getValue("template");
}
} else {
this.parsingTextValue = tags.contains(tag);
}
}
}
@Override
public void endElement(final String uri, final String name, final String tag) {
if (tag == null) return;
if (parsingDescription && "OpenSearchDescription".equals(tag)) {
this.parsingDescription = false;
} else if (this.parsingTextValue) {
final String value = this.buffer.toString().trim();
this.buffer.setLength(0);
if (tags.contains(tag)) {
this.items.put(tag, value);
}
}
}
@Override
public void characters(final char ch[], final int start, final int length) {
if (this.parsingTextValue) {
this.buffer.append(ch, start, length);
}
}
public String getRSSTemplate() {
return this.rssurl;
}
public String getRSSorAtomUrl() {
return this.rssurl == null ? this.atomurl : this.rssurl;
}
public String getShortName() {
return items.get("ShortName");
}
public String getItem(final String name) {
// retrieve item by name
return this.items.get(name);
}
public int items() {
return this.items.size();
}
}