我在 Github 上找到了一个代码，它使用 DBpedia Lookup 发送单词并从 DBpedia 获取候选 URI。问题是：所有的 URI 都带有单词Category. 例如，对于Berlin它返回的单词：
代替
如果我将第一个 URI（带有“类别”的那个）放在浏览器上，它不会向我显示与主题“History_of_Berlin”相对应的页面，它会返回一个包含链接列表的页面以及我可以在哪里找到“History_of_Berlin”的链接。但是，如果我输入第二个 URI（没有“类别”的那个），它会返回与主题“History_of_Berlin”对应的页面。如何避免从查找中返回这些带有“类别”的 URI？
代码
package com.knowledgebooks.info_spiders;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpMethod;
import org.apache.commons.httpclient.methods.GetMethod;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import java.io.IOException;
import java.io.InputStream;
import java.net.URLEncoder;
import java.util.*;
/**
* Copyright Mark Watson 2008-2010. All Rights Reserved.
* License: LGPL version 3 (http://www.gnu.org/licenses/lgpl-3.0.txt)
*/
// Use Georgi Kobilarov's DBpedia lookup web service
// ref: http://lookup.dbpedia.org/api/search.asmx?op=KeywordSearch
// example: http://lookup.dbpedia.org/api/search.asmx/KeywordSearch?QueryString=Flagstaff&QueryClass=XML&MaxHits=10
/**
* Searches return results that contain any of the search terms. I am going to filter
* the results to ignore results that do not contain all search terms.
*/
public class DBpediaLookupClient extends DefaultHandler {
public DBpediaLookupClient(String query) throws Exception {
this.query = query;
HttpClient client = new HttpClient();
String query2 = query.replaceAll(" ", "+"); // URLEncoder.encode(query, "utf-8");
HttpMethod method =
new GetMethod("http://lookup.dbpedia.org/api/search.asmx/KeywordSearch?QueryString=" +
query2);
try {
client.executeMethod(method);
System.out.println(method);
InputStream ins = method.getResponseBodyAsStream();
SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser sax = factory.newSAXParser();
sax.parse(ins, this);
} catch (HttpException he) {
System.err.println("Http error connecting to lookup.dbpedia.org");
} catch (IOException ioe) {
System.err.println("Unable to connect to lookup.dbpedia.org");
}
method.releaseConnection();
}
private List<Map<String, String>> variableBindings = new ArrayList<Map<String, String>>();
private Map<String, String> tempBinding = null;
private String lastElementName = null;
public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
//System.out.println("startElement " + qName);
if (qName.equalsIgnoreCase("result")) {
tempBinding = new HashMap<String, String>();
}
lastElementName = qName;
}
public void endElement(String uri, String localName, String qName) throws SAXException {
//System.out.println("endElement " + qName);
if (qName.equalsIgnoreCase("result")) {
if (!variableBindings.contains(tempBinding) && containsSearchTerms(tempBinding))
variableBindings.add(tempBinding);
}
}
public void characters(char[] ch, int start, int length) throws SAXException {
String s = new String(ch, start, length).trim();
//System.out.println("characters (lastElementName='" + lastElementName + "'): " + s);
if (s.length() > 0) {
if ("Description".equals(lastElementName)) {
if (tempBinding.get("Description") == null) {
tempBinding.put("Description", s);
}
tempBinding.put("Description", "" + tempBinding.get("Description") + " " + s);
}
if ("URI".equals(lastElementName)) tempBinding.put("URI", s);
if ("Label".equals(lastElementName)) tempBinding.put("Label", s);
}
}
public List<Map<String, String>> variableBindings() {
return variableBindings;
}
private boolean containsSearchTerms(Map<String, String> bindings) {
StringBuilder sb = new StringBuilder();
for (String value : bindings.values()) sb.append(value); // do not need white space
String text = sb.toString().toLowerCase();
StringTokenizer st = new StringTokenizer(this.query);
while (st.hasMoreTokens()) {
if (text.indexOf(st.nextToken().toLowerCase()) == -1) {
return false;
}
}
return true;
}
private String query = "";
}