package Published;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.BasicResponseHandler;
import org.apache.http.impl.client.DefaultHttpClient;
import org.w3c.dom.Document;
import org.xml.sax.InputSource;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.*;
public class Discovery {
public Discovery() {
}
public String hasHub(Document doc) throws Exception {
String hub = null;
XPathFactory factory = XPathFactory.newInstance();
XPath xPath = factory.newXPath();
XPathExpression xPathExpression;
try{
xPathExpression = xPath.compile("/feed/link[@rel='hub']/@href");
hub = (String) xPathExpression.evaluate(doc);
if ((hub==null)||(hub=="")){
xPathExpression = xPath.compile("//link[@rel='hub']/@href");
hub = (String) xPathExpression.evaluate(doc);
}
if (hub ==""){
return null;
}
return hub;
} catch (XPathExpressionException e) {
return null;
}
}
public String hasTopic(Document doc){
String topic = null;
XPathFactory factory = XPathFactory.newInstance();
XPath xPath = factory.newXPath();
XPathExpression xPathExpression;
try {
xPathExpression = xPath.compile("/feed/link[@rel='self']/@href");
topic = (String) xPathExpression.evaluate(doc);
if ((topic==null)||(topic.equals(""))){
xPathExpression = xPath.compile("//link[@rel='self']/@href");
topic = (String) xPathExpression.evaluate(doc);
}
if (topic.equals("")){
return null;
}
return topic;
} catch (XPathExpressionException e) {
return null;
}
}
public String getContents(String feed) throws Exception {
String response = null;
HttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet(feed);
ResponseHandler<String> responseHandler = new BasicResponseHandler();
String responseBody = httpclient.execute(httpget, responseHandler);
response = (responseBody);
httpclient.getConnectionManager().shutdown();
return response;
}
public String getHub(String feedurl) throws Exception {
DocumentBuilderFactory Factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = Factory.newDocumentBuilder();
Document doc = builder.parse(new InputSource(new StringReader(
getContents(feedurl))));
XPathFactory factory = XPathFactory.newInstance();
XPath xPath = factory.newXPath();
XPathExpression xPathExpression;
String hub;
xPathExpression = xPath.compile("/feed/link[@rel='hub']/@href");
hub = (String) xPathExpression.evaluate(doc);
if ((hub==null)||(hub.equals(""))){
xPathExpression = xPath.compile("//link[@rel='hub']/@href");
hub = (String) xPathExpression.evaluate(doc);
}
return hub;
}
public HashMap<String, String> getHubs(ArrayList<String> feedurls) {
Iterator<String> i = feedurls.iterator();
HashMap<String, String> hashtable = new HashMap<String, String>();
while (i.hasNext()) {
String feedurl = i.next();
try {
hashtable.put(feedurl, getHub(feedurl));
} catch (Exception e) {
}
}
return hashtable;
}
}